Method for determining power consumption, supervision system and electric installation comprising same

TECHNICAL FIELD OF THE INVENTION

The invention relates to a method for determining the power consumption in an electrical installation comprising a group of several individual power distribution between multiple branches and loads the incoming main supply line, with branches connecting group power supply. A corresponding method comprises an act of performing and recording measurements performed on the incoming power line and to enable the establishment of full power consumed by a group of branches.

The invention also relates to a control system of the group of several individual power distribution of branches among multiple loads in the electrical system, the system comprising at least:

- A device for performing measurements on the main supply line part connecting the branches with a group of the source of electrical power,

- Memory for storing these measurements, allowing for the total power consumed by a group of branches,

- Transducer particular branch equipment among branches.

Furthermore, the invention relates to an electrical installation comprising a group of several individual power distribution of branches among several loads, a main supply line inbound linking group branches with a source of electrical power.

BACKGROUND

Individuals, as well as other economic agents have shown a growing interest in the management of their own consumption of electric power. One direction of this control consumption based on detailed knowledge of the various specific consumption within total consumption. For example, residents of the house or the property of another type may be interested in their electricity consumption attributable to heating, that falls on the light, and / or that is necessary for a specific piece of equipment, not content with only the knowledge of the full housing consumption as a whole .

Currently occupants housing, usually can have access to their total electricity consumption of electric power through the meter, mounted on the connecting line to the public distribution network, which supplies electricity to homes. If it is desired to know the individual consumption, for example, a specific item of equipment within the housing, the branch, which is connected to the piece of equipment, it is equipped with a counter of the electric power consumption. In the appended Fig. 1 is a diagram showing an example of a modern home electrical installation, in which several electric power consumption counters 101 provide information on the various individual consumption, form part of the total electric power consumption.

In this FIG. 1, reference numeral 102 designates a transformer connected to the public distribution network of electric power. Supply side line counter 103 equipped with the electric power consumption, connects with the electrical transformer unit 102. Identical or similar to the counter 103, each electric power consumption of the counter 101 operates in one of several electrical power distribution feeders to multiple loads 104. The wired network is provided for transmitting various counters counts to the central electronic control unit measurement 105 that includes the meter readings.

Counter electric power consumption is expensive and cumbersome. When it is desirable to be able to control a number of individual power consumption within the facility, additional costs resulting from replicating the counters of electric power consumption, can be a real obstacle to the implementation of effective control of individual consumption of the system. Features such multiplication counters can also prevent a lack of available space in many common electrical switchboards, currently installed in private homes.

Furthermore, studies have been conducted to identify the type of load to set by means of mathematical analysis of the supply current specificity of such facility. Patents and / or patent applications US 2010/0287489, JP 2003/070186, WO 2010/037988, WO 2001/177696, EP 2000780, EP 2026299, W0 1010/014762 reflect this research. The solutions that are offered to them, are complex in terms of software tools expensive and actually not allowing user access to individual consumption equipment form part of the electrical installation.

SUMMARY OF THE iNVENTION

The object of the invention is to at least reduce the cost of providing access to information on individual energy consumption, constituting part of the total measured power consumption in the electric installation of the AC.

According to the invention this problem is solved by the method of the above type, comprising the steps of:

a) detecting a change of power consumption in the installation, and

b) reading the information relating to the electric current in the particular branch, among said branches by a transmitter installed in that particular branch, then

c) using the information read via the transmitter installed in a particular branch is set to specify, according to which said variation has occurred in that particular branch, then

d) using data from a measurement performed on the primary input power line before change, and data from measurements performed on the primary input power line after the change, in addition to said instructions define individual specific consumption of said particular branch.

Some of the load is always consume the same energy if their power is off. In other kinds of loads, the power consumption can be varied between several different values, but it is always variable in steps.

It has been found that, provided that the nature of loads to an electrical installation is taken into consideration, the individual power consumption of the load attached to one of several branches that may be derived while no measurements are available for a set of electrical parameters characterizing the operation of the load. In some cases, in particular, the power consumption of the load connected to one of several branches that may be inferred by monitoring changes affecting this consumption. It can be inferred from the measured values ​​characterizing the full electric power branches set of food before and after these changes and, possibly, from other measurements.

However, the availability of measurement values ​​characterizing the full electrical power supply to the set of several branches, is the usual case in the distribution of electricity. This is especially true in case of electrical installations in which a plurality of feeders connected to the same inlet connected to a public distribution network of electrical power and in which the inlet is equipped with a counter electric power consumption. In this case, the invention simplifies the equipment instrumentation specific branches, where the consumption must be controlled. In particular, these gauges can be reduced to the current probe, if only control changes affecting consumption in the branches. current detector is usually much cheaper and less bulky than the electrical power consumption meter. The same is the case with the current sensor or ammeter.

A method of determining the electric power consumption may include one or more of the other preferred features, separately or in combination, such as those defined below.

Preferably step d) comprises the substeps of:

d1) by combining said instructions and tables, establishing at least one correspondence between at least a concrete branch and at least one method from a set of several methods of determining an individual energy consumption in a branch selected method of determining ways to set individual consumption,

d2) using the selected method depends on your individual energy consumption.

Individual distribution branches can be connected in parallel. Preferably, when the source of electrical power is an AC power source, a concrete method of the kit comprises a method of performing time and recording measurements of the total supply voltage of several branches, measuring force values ​​and phase shift a full supply current group of several branches and force measurements specific individual current flowing in a particular branch of the group of branches. Preferably, the specific method comprising the step of:

e) using the measurement is substantially constant over the full voltage change power measurement values ​​of the phase shift and total current before and after the change and the individual current measuring specific force before and after the changes, determined individual power consumed by the particular branch.

Preferably, in step e) individual power determined in consideration of the fact that the set of individual currents flowing in the band branches except the particular individual current is added to the substantially same amount by changing the end, compared with what occurs to change and that should be performed simultaneously the following two conditions:

- The total current to change to be substantially equal to the addition of a substantially constant amount of current for a particular individual before the change, and

- The total current after the change to be substantially equal to the addition amount is substantially constant current to a particular individual after modification.

Preferably, in step e), an abnormal decision rule of two possible solutions.

Individual distribution branches can be connected in parallel. Preferably, the source of electrical power is a source of constant current, the specific method of the kit comprises an act of measuring the full supply voltage group of several branches and force measurements particular individual current flowing in a particular branch of the group of branches, the particular method comprises the step of:

e) using the measurement of a voltage and measuring the current strength of a particular individual, the individual is determined the power consumed in the specific branch.

Preferably, step e) comprises the substeps of:

e1) using measured force values ​​and phase shift of the total current before and after the change and the individual current measuring specific force before and after the change, determining said substantially unchanging sum of the individual currents simultaneously satisfying the two conditions mentioned.

e2) determine which component needs to be added to a substantially constant sum of the individual currents to obtain the total current, and this component is to identify specific individual current

e3) calculating a specific individual capacity, as a product of the total voltage and current of a particular individual.

Preferably, in sub-step e1), said substantially unchanged sum of the individual currents is determined by the numerical solution of a system of two equations with two unknowns:

<maths id="" num="1"><img file="00000001.jpg" he="14" wi="54" img-format="jpg" img-content="undefined" /></maths>

Where <maths id="" num="2"><math display="block"><mrow><msubsup><mi>I</mi><mrow><mn>3</mn><mi>A</mi></mrow><mn>2</mn></msubsup></mrow></math><img file="00000002.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths> and <maths id="" num="3"><math display="block"><mrow><msubsup><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow><mn>2</mn></msubsup></mrow></math><img file="00000003.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths> They are, respectively, a square measure of a particular strength to change individual current and the square power measure the current after a specific individual changes

where X_A and Y_A are respectively the x-axis and y-axis of the vector representation of the total current, as measured before the change in the vector diagram,

where X_B and Y_B are respectively the x-axis and y-axis of the vector representation of the total current is measured after a change in the vector diagram,

and wherein X_S and Y_S are two unknowns, which are respectively the x-axis and y-axis of the vector representation of said substantially constant sum of the individual currents in the vector diagram before and after the change.

Preferably, step e) comprises the substeps of:

- Determine the value of the force AB by the following relationship:

<maths id="" num="4"><math display="block"><mrow><mi>A</mi><mi>B</mi><mo>=</mo><msqrt><mrow><msubsup><mi>I</mi><mi>A</mi><mn>2</mn></msubsup><mo>+</mo><msubsup><mi>I</mi><mi>B</mi><mn>2</mn></msubsup><mo>-</mo><mn>2</mn><mo>×</mo><msub><mi>I</mi><mi>A</mi></msub><mo>×</mo><msub><mi>I</mi><mi>B</mi></msub><mo>×</mo><mi>cos</mi><mo stretchy="false">(</mo><msub><mi>ψ</mi><mi>B</mi></msub><mo>-</mo><msub><mi>ψ</mi><mi>A</mi></msub><mo stretchy="false">)</mo></mrow></msqrt></mrow></math><img file="00000004.jpg" he="8" wi="73" img-format="jpg" img-content="undefined" /></maths>

where I_A and ψ_A are, respectively, the measured force and phase shift of the total current (I) before the change, and where I_B and ψ_AT They are, respectively, the measured force and phase shift of the total current after the change,

- Determine the value ψ₁ angle by the following relation:

<maths id="" num="5"><math display="block"><mrow><msub><mi>ψ</mi><mn>1</mn></msub><mo>=</mo><mi>arcsin</mi><mrow><mo>(</mo><mrow><mfrac><mrow><msub><mi>I</mi><mi>B</mi></msub><mo>×</mo><mi>cos</mi><msub><mi>ψ</mi><mi>B</mi></msub><mo>-</mo><msub><mi>I</mi><mi>A</mi></msub><mo>×</mo><mi>cos</mi><msub><mi>ψ</mi><mi>A</mi></msub></mrow><mrow><mi>A</mi><mi>B</mi></mrow></mfrac></mrow><mo>)</mo></mrow></mrow></math><img file="00000005.jpg" he="12" wi="66" img-format="jpg" img-content="undefined" /></maths>.

- Determine the value ψ₂ angle by the following relation:

<maths id="" num="6"><math display="block"><mrow><msub><mi>ψ</mi><mn>2</mn></msub><mo>=</mo><mi>arccos</mi><mrow><mo>(</mo><mrow><mfrac><mrow><msubsup><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow><mn>2</mn></msubsup><mo>+</mo><mi>A</mi><msup><mi>B</mi><mn>2</mn></msup><mo>-</mo><msubsup><mi>I</mi><mrow><mn>3</mn><mi>A</mi></mrow><mn>2</mn></msubsup></mrow><mrow><mn>2</mn><mo>×</mo><msub><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>×</mo><mi>A</mi><mi>B</mi></mrow></mfrac></mrow><mo>)</mo></mrow></mrow></math><img file="00000006.jpg" he="13" wi="51" img-format="jpg" img-content="undefined" /></maths>.

where I_3A and I_3B They are, respectively, a specific measure of the strength of individual changes to the current measure and current strength of a particular individual after modification.

Preferably, step e) comprises the substeps of:

- A particular individual power after the change is determined by the following relationship:

<maths id="" num="7"><math display="block"><mrow><msub><mi>P</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>=</mo><mi>U</mi><mo>×</mo><msub><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>×</mo><mi>sin</mi><mo stretchy="false">(</mo><msub><mi>ψ</mi><mn>1</mn></msub><mo>+</mo><msub><mi>ψ</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow></math><img file="00000007.jpg" he="6" wi="48" img-format="jpg" img-content="undefined" /></maths>

where P_3B and U are respectively referred to a specific individual capacity after the change and the full supply voltage.

Preferably, the method of determining the power consumption includes the step of:

- Phase shift of a particular individual after the current change is determined by the following relationship:

<maths id="" num="8"><math display="block"><mrow><msub><mi>ψ</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>=</mo><mi>π</mi><mo>/</mo><mn>2</mn><mo>-</mo><mo stretchy="false">(</mo><msub><mi>ψ</mi><mn>1</mn></msub><mo>+</mo><msub><mi>ψ</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow></math><img file="00000008.jpg" he="6" wi="39" img-format="jpg" img-content="undefined" /></maths>

where ψ_3Β It is a phase shift of a particular individual current after the change.

Preferably, in one method of determining the power consumption of the individual, the individual power consumed in one of the branches is defined as equal to the difference between the total power consumed by a group of branches before the change, and the total power consumed in the branches of the group after the change.

Preferably, in one method of determining the individual power consumption of individual measured power consumption in a branch of the group of branches.

The object of the invention is to provide a well control system which is a system of the above type and which comprises a computing device configured to:

- Detect variation in the electric power consumption of the installation by the data exchange with at least one of the devices that are to perform the measurement device and the transducer, and

- Control information related to the electrical current in the particular branch, received from the transmitter, which is equipped with this particular branch, then

- Through information provided by the transducer, which has a specific branch, setting an indication that said change has occurred in that particular branch, then

- Using data from a measurement performed on the input power line before change, and data from measurements performed on the input power line after the change, and said instructions identify specific individual power consumption of said particular branch.

The control system according to the invention may include one or more preferred features, separately or in combination, in particular among those defined below.

Preferably, the computing device has several ways to determine the power consumption in the individual branches, and a table for establishing at least one match between the at least one branch and at least one way. Preferably, the computing device is configured to select a particular method among the methods for determining an individual consumer by combining said instructions and tables, and for determining the power consumption of a particular individual with the particular mode selected.

Preferably, the electrical system AC control system is adapted to perform in time and recording measurements of the total supply voltage is a group of several branches, measuring the force values ​​and phase shift a full supply current group of several branches and force measurements particular individual current flowing in a particular branch groups of branches. Preferably, the computing device comprises means for determining the individual power consumed by a particular branch, using the measurement substantially constant full voltage during the modification, measurement force values ​​and phase shift of the total current before and after the change and the measurement of force a particular individual current before and after change .

Preferably, the means for determining the individual capacity is arranged to determine the individual capacity, given that the set of the individual currents flowing in the branches of the group, except for the particular individual current is added to the substantially same amount by changing the end, compared with what has place before the change, and that the following two conditions must be met simultaneously:

- Total current before the change should be substantially equal to the addition of a substantially constant amount of current for a particular individual before the change, and

- The total current after the change to be substantially equal to the addition amount is substantially constant current to a particular individual after modification.

Preferably, the computing device comprising means for excluding abnormal solutions of two possible solutions.

Preferably, the electrical system for a DC control system is arranged to perform measurements of the total supply voltage from a group of several branches and individual specific force measurements of the current flowing in a particular branch of the group of branches. Preferably, the device comprises computing means for determining the individual power consumed by a particular branch, with the total voltage measurement and the particular individual force measuring current.

Preferably, the device comprises computing means for determining the individual power consumed in one of the branches is equal to the difference between the total power consumed by a group of branches before the change, and the total power consumed in the branches of the group after the change.

Preferably, the computing device is adapted to perform a method as defined above.

Another object of the invention is to provide an electrical installation, which represents a unit of the above type which has a control system, as defined above. Device for the measurement is set in the incoming feed line. The specific branch of the branches has a transmitter.

BRIEF DESCRIPTION OF DRAWINGS

From the accompanying figures in FIG. 1 is a simplified diagram of an electrical installation according to the prior art.

Other advantages and features will become more apparent from the following description of specific embodiments of the invention, given only by way of non-limiting examples and illustrated in the accompanying drawings, in which:

FIG. 2 - a simplified circuit diagram of the electrical installation according to the invention;

FIG. 3 - block diagram of a method that corresponds to the invention and which is implemented in the individual volume control of the consumption, the consumption is part of the electrical system of FIG. 2;

FIG. 4 - a vector diagram illustrating the method steps for determining one of the aforementioned individual consumptions, in the method according to the invention;

FIG. 5 - a vector diagram continuing FIG. 4 further showing the additional detail regarding the operations included in the method illustrated in FIG. 4;

FIG. 6 - a vector diagram continuing FIG. 4 further showing the additional detail about possible ways of implementing the method schematically represented in FIG. 4.

DESCRIPTION OF PREFERRED EMBODIMENT

Electrical installation 1 is suitable for performing the method according to the invention is shown in FIG. 2. For clarity, FIG. 2 is simplified and certain conventional components are omitted therein. In particular, it shows only one phase, while the neutral is not shown.

Electrical installation 1 may belong to the final consumer, and be located in the neighborhood or building, such as an apartment building or office block, where there are several different loads, which must be supplied, and which needs to be performed on the distribution of electric power. This electrical installation 1 can, in particular, be that of a private house or apartment buildings.

Electrical installation 1 is provided with an electric power source with alternating sinusoidal current 2 to which it is connected by incoming feed or supply line 3 and which may be, for example, public network distribution of electric power.

Multiple feeders connected to the cart 3. Each of them forms part of one or more of the four branches, fed in parallel, which are connected to the load 5, which must be powered. In the illustrated example, there are four such branch 4. It is obvious that their number may be different from four.

Approach 3 is equipped with a 6 meter consumption of electric power, which measures the time in several parameters, characteristic for full power group 4 branches, namely, the full supply voltage U and power values ​​and phase shift a full supply current I, flowing in the cart 3. An apparatus for performing the same measurement as that performed by the counter 6 may be used instead of the latter being not directly counter the electric power consumption.

One or more of the four branches may be provided, each, a current sensor or ammeter 7. In the example 7 ammeter measures the intensity of the individual current I₃ in the branch 4.

One or more branches can be provided with four each, the current sensor 8. In the example shown, sensor 8 detects the current flows or not individual current I₃ in the branch 4.

One or more of the four branches may be provided, each, counter 9, the electric power consumption, which may be identical to the counter 6. In the example shown, the consumption meter 9 measures the time power consumed by four branches, where the current I flows₄. It can also measure a variety of parameters characteristic of the electric power supply in this branch 4, and provide the possibility of determining the power consumed in it.

Each of the pieces of equipment formed by ammeter 7, the current sensor 8 and the counter 9, the electric power consumption, has at least one transducer which converts an electrical parameter in an electrical signal representing the measurement or other information element.

One or more of the four branches may not have such a transducer, which may result from the fact that their power consumption is not monitored, or correspond to the case when this consumption can be derived without knowledge of the corresponding branch 4. In the example shown, the detection or measurement device offline 4 in the branch in which the current I flows₁.

Reference numeral 10 denotes a common low voltage panel, where the various electrical devices, including counters 6 and 9, the electric power consumption, ammeter 7 and 8, a current detector.

11 Communication system allows the central electronic unit 12 to communicate the measurements to the measurement and detection devices, ie, 6 and 9 meters electric power consumption, ammeter 7 and 8, the current detector. The central unit 12 collects and stores measurement time, that is, throughout the operation of the electrical apparatus 1, data coming from the measurement and detection instrumentation. Preferably, transmission 13 is performed by the wireless data communication such as a radio frequency link that takes place in the example shown. However, the relationship between the gauges 13 and 12, the central unit can be wired or mixed.

The data collected by central unit 12, stored in the memory 14 of the central unit 12, which also comprises a computing device 15 for processing.

6 and 9 meters consumption of electric power, ammeter 7, the current detector 8, communications system 11 and the central measuring unit 12 together form the whole or part of the system, which corresponds to the invention and which is more precise operation control system 1 of an electrical installation.

The central unit 12 is equipped with at least one port 16, I / O, by means of which it can communicate with an external device, such as an administration computer, monitor and / or control, by means of which the operator fills the data in Table 18, the computing device 15, in particular, in accordance with the types of loads 5a, 5b, 5c and 5d in the branches 4 and in accordance with the manner in which these branches are respectively equipped with four measuring devices.

5a load connected to the branch 4, where the current I flows₁, It has a constant impedance. It consumes the active power and / or reactive power, each of which is either equal to zero when disabled, or substantially equal to a fixed value. This value is, in addition, a single value in an electrical installation 1, which is written in the table 18 by classifying branch 4, in which the current I flows₁According to the first category. If the change in the total power consumption of the installation 1, a single value is equal to the above, it is known that this change in power to be assigned to a branch 4, in which the current I flows₁.

5b load 4 connected to the branch in which the current I flows₂, It has a constant impedance. It consumes the active power and / or reactive power, each of which is zero when disabled, or substantially equal to a fixed value. This value is, in addition, a single value in an electrical installation 1, which is written in the table 18 by classifying branch 4, in which the current I flows₂According to the second category.

The four branches, where the current I flows₃, The power consumption changes are performed stepwise, because of the nature of its load 5c. In other words, the power consumed in the branch 4 is substantially constant between the two changes, that is written in the classification table 18 by the branch in which flows the current I₃According to the third category.

The four branches, where the current I flows₄Consumed active power and / or reactive power may change gradually over long periods of time, which is written in the table 18 by classifying branch in which the current I flows₄According to the fourth category.

Table 18 is full, when a step configuration, the operator and / or the computing device 15 and undergoing the test for classifying each of the four branches of both the observed relating to one of the above mentioned first, second, third and fourth categories.

The computing unit 15 performs a process, the logic of which is shown in FIG. 3. In a first step 20 of this process, the computing unit 15 controls the appearance changes affecting the current strength in the branches 4 and / or the total consumption of electrical installation 1. When such a change is detected, the computing device 15 proceeds to step 21 where it performs filtering to distinguish between significant and lasting changes to other minor and / or time changes.

Significant changes are defined as exceeding the predetermined threshold selected based on various data, such as type of use of the electrical installation 1. Temporal changes are defined as having a duration longer than a predetermined time delay, for example, about 2 to 3 seconds. If answered in the negative to the question of whether the observed change in a significant and prolonged, computing unit 15 returns to step 20 control. In the opposite case the step 22 is started.

At this stage 22 the calculating device 15 determines to what happened four branch power consumption change. If a change has occurred in the branch in which the current I flows₁Computing device concludes that the total power consumption change installation 1 essentially equal to the power absorbed by the load alone 5a, when it is active. In other cases, the computing device 15 detects the origin of changing consumption information provided by the current detector 8, an ammeter 7 and 9 meter.

The computing device 15 has available several methods 30, 31, 32 and 33 to determine the individual power consumed in the branch 4. Each of these modes of action of 30 to 33 is suitable for the case among those used in the first, second, third and fourth higher mentioned categories.

When it discovers to which 4 branches changed power consumption, computing device 15 selects the mode of action of 30, 31, 32 or 33, which will be used to determine the power consumption in this branch 4. To do so, still in step 22, the computing device 15 refers to the table 18, which is a correspondence table, and where one of the above four categories is assigned to each of the observed branches 4, that is one of the modes of action of 30-33. After step 22, the computing unit 15 operates in accordance with the method steps 30, 31, 32 or 33, which it has chosen.

30 A method for determining the individual capacity to like branches 4, in which the power consumption changes are made in steps, due to the nature of their loads. In other words, it is suitable when the power consumption in the branch 4 is substantially constant between two changes.

30 A method for determining an individual power will now be described in case of change in the intake branch 4, in which the current I flows₃. In step 40 of the method steps 30, computing device 15 answers the question of whether an individual current I₃ to zero or not changed.

If so, then the simplified calculation in step 41, which is to determine the individual power consumption of the load 5 seconds after the change as an equal change in the total power consumption of the electrical installation and determined counter 6, power consumption, or only of his measurements of the parameters characteristic of the total supply group branches of the electric power 4, i.e. voltage, current and phase shift of the power supply.

If the personal current I₃ was not null before the change, the computing device 15 performs step 42 in which it determines new individual power consumed in the branch 4 which flows the current I₃While it operates in the manner explained below by means of the vector diagram in Fig. 4.

This method takes into account the actions that electrical installation 1 is provided with a substantially sinusoidal current with little or no harmonic distortion. In the case of harmonic distortions, the individual power computing unit 15 determined to be less accurate.

At least a power calculation formulas presented below and / or in the appended claims mentioned voltage and current strength are (rms) values.

The present vector <maths id="" num="9"><math display="block"><mover accent="true"><mi>U</mi><mo>→</mo></mover></math><img file="00000009.jpg" he="6" wi="4" img-format="jpg" img-content="undefined" /></maths>FIG. 4 voltage across the terminals of each branch 4 is a complete supply voltage U Installation 1. Change the power consumption is very small, it has little effect on him. Therefore, it is considered that it is the total voltage U is not changed when you change the power consumption. On the other hand, this change affects the total current I in the same manner as in the individual current I₃.

FIG. 4, vector<maths id="" num="10"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>A</mi></msub></mrow></math><img file="00000010.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths> and the vector <maths id="" num="11"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>A</mi></mrow></msub></mrow></math><img file="00000011.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths><sub />are, respectively, a graphical representation of the total current I and a graphical representation of the individual current I₃ at the same time, which is before the first time change. Vector<maths id="" num="12"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>B</mi></msub></mrow></math><img file="00000012.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths> and the vector <maths id="" num="13"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>B</mi></mrow></msub></mrow></math><img file="00000013.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths> are, respectively, a graphical representation of the total current I and a graphical representation of the individual current I₃ at another time, which is the second time after the change. Both the first and the second time to pick out the corresponding phase change. In other words, each of them is in a stable and permanent operating phase electrical system 1, so that transients are excluded.

The voltage values, power and phase shift measured by the counter 6, define vectors <maths id="" num="14"><math display="block"><mover accent="true"><mi>U</mi><mo>→</mo></mover></math><img file="00000009.jpg" he="6" wi="4" img-format="jpg" img-content="undefined" /></maths>. <maths id="" num="15"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>A</mi></msub></mrow></math><img file="00000010.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths> and <maths id="" num="16"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>B</mi></msub></mrow></math><img file="00000012.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths>Which therefore known. In contrast, the parameters characterizing the individual current I₃Not measured. In fact, only the measured force, except the phase shifts as regards the individual current I₃.

power change was only four branches, where the current I flows₃. Therefore, the individual set of currents flowing in the other branches 4, except for the individual current I₃Is added to a substantially unchanged amount of time between the first change to the power consumption and the second time after this change. In this example, this sum is the sum of the currents I₁ and I₂. Its graphical representation of FIG. 3 is a vector<maths id="" num="17"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>S</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000014.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths>Where D - the beginning of the orthonormal coordinate system.

Since this vector <maths id="" num="18"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>S</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000014.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths> It is the same before and after the change, it should be simultaneously satisfied as follows:

<maths id="" num="19"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>S</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000014.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths> + <maths id="" num="20"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>A</mi></mrow></msub></mrow></math><img file="00000015.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths>=<maths id="" num="21"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>A</mi></msub></mrow></math><img file="00000010.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths> (=<maths id="" num="22"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>A</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000016.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths>) and

<maths id="" num="23"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>S</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000014.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths> + <maths id="" num="24"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>B</mi></mrow></msub></mrow></math><img file="00000017.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths>=<maths id="" num="25"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>B</mi></msub></mrow></math><img file="00000018.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths> (=<maths id="" num="26"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>B</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000019.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths>)

This is shown in FIG. 4.

The norm of the vector <maths id="" num="27"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>A</mi></mrow></msub></mrow></math><img file="00000020.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths> It is the measurement of I_3A I force₃ current to change. The norm of the vector<maths id="" num="28"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>B</mi></mrow></msub></mrow></math><img file="00000021.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths> It is the measurement of I_3B I force₃ current after the change. Point S is the intersection of two circles, namely, the circle with center A and radius I_3A current I₃As measured before the change, and the circle with center B and radius c I_3B current I₃As measured after the change.

Based on the foregoing, the first course of action is in the numerical solution of the following system of two equations with two unknowns:

<maths id="" num="29"><img file="00000001.jpg" he="14" wi="54" img-format="jpg" img-content="undefined" /></maths> (1)

X_A and Y_A are the Cartesian coordinates of the vector <maths id="" num="30"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>A</mi></msub></mrow></math><img file="00000010.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths> in the above orthonormal coordinate system, in which only the origin O shown for clarity.

X_B and Y_Bare the Cartesian coordinates of the vector <maths id="" num="31"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>B</mi></msub></mrow></math><img file="00000012.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths> in the same orthonormal coordinate system.

X_S and Y_S are two unknowns are the Cartesian coordinates of the vector <maths id="" num="32"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>S</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000014.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths>Again in the same orthonormal coordinate system.

The computing device 15 can solve the system (1) equations with two unknowns using a mathematical method of numerical expansion, based on the gradual change in X_S and Y_S under the control of the convergence criteria.

For example, a numerical method for determining the point S can be to move step by step to one of the uk those indicated two circles, which are the circle with center A and radius I_3A forces and the circle with center B and radius c I_3B force. At each step, one of the circles is checked whether or not the location in the vicinity of the other circle.

It should be noted that the system (1) has two solutions, which correspond to S and S 'points in Fig. 4. S 'point corresponds physically abnormal decision, which must be eliminated to keep only other solution, which corresponds to point S.

Excluding the point S 'can be performed by computing, for each of the points S and S', the active and reactive power before and after the change in the power of the observed and storing only one of two points S and S ', which for this capacity satisfy the following criteria:

- The active power before and after the change of power should be positive, given that the assumed load 5c consuming, but does not provide active power,

- Reactive power before and after the change of power should have the same sign and conform to the nature of the load or the load in the branch 5c 4, ie, in case of positive capacitive loads 5c and negative in the case of inductive loads 5c.

Once the point S is determined, the vector <maths id="" num="33"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>B</mi></mrow></msub></mrow></math><img file="00000021.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths> and force values ​​and phase shift characteristic for the new current I₃It is easily determined using the following relationship: <maths id="" num="34"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>B</mi></mrow></msub></mrow></math><img file="00000021.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths>=<maths id="" num="35"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mi>B</mi></msub></mrow></math><img file="00000012.jpg" he="7" wi="5" img-format="jpg" img-content="undefined" /></maths>-<maths id="" num="36"><math display="block"><mrow><mover accent="true"><mrow><mi>O</mi><mi>S</mi></mrow><mo stretchy="true">→</mo></mover></mrow></math><img file="00000014.jpg" he="6" wi="7" img-format="jpg" img-content="undefined" /></maths>.

New power P_3BThat is, after the change, and consumed in the branch 4, in which the current I flows₃And then calculated the computing device 15, the scalar product of vectors <maths id="" num="37"><math display="block"><mover accent="true"><mi>U</mi><mo>→</mo></mover></math><img file="00000009.jpg" he="6" wi="4" img-format="jpg" img-content="undefined" /></maths> and <maths id="" num="38"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>B</mi></mrow></msub></mrow></math><img file="00000021.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths>: P_3B = <maths id="" num="39"><math display="block"><mover accent="true"><mi>U</mi><mo>→</mo></mover></math><img file="00000009.jpg" he="6" wi="4" img-format="jpg" img-content="undefined" /></maths>·<maths id="" num="40"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>B</mi></mrow></msub></mrow></math><img file="00000021.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths>. The former power P_3A 4 in this branch can also be calculated in a similar way, namely by the ratio Ρ_3A = <maths id="" num="41"><math display="block"><mover accent="true"><mi>U</mi><mo>→</mo></mover></math><img file="00000009.jpg" he="6" wi="4" img-format="jpg" img-content="undefined" /></maths>·<maths id="" num="42"><math display="block"><mrow><msub><mover accent="true"><mi>I</mi><mo>→</mo></mover><mrow><mn>3</mn><mi>A</mi></mrow></msub></mrow></math><img file="00000020.jpg" he="7" wi="6" img-format="jpg" img-content="undefined" /></maths>.

FIG. 6 illustrates the geometric and trigonometric ratios, which are used by the second method of action to determine the power consumption in the branch 4, where the current I flows₃. Instead of the first method steps described above or in addition thereto, the computing device 15 may implement the second mode of operation, which is based on the analytical calculation and which will be discussed below.

The triangle AOB shown in FIG. 5, we have the following relationship:

<maths id="" num="43"><math display="block"><mrow><mi>A</mi><msup><mi>B</mi><mn>2</mn></msup><mo>=</mo><msubsup><mi>I</mi><mi>A</mi><mn>2</mn></msubsup><mo>+</mo><msubsup><mi>I</mi><mi>B</mi><mn>2</mn></msubsup><mo>-</mo><mn>2</mn><mo>×</mo><msub><mi>I</mi><mi>A</mi></msub><mo>×</mo><msub><mi>I</mi><mi>B</mi></msub><mo>×</mo><mi>cos</mi><mo stretchy="false">(</mo><mi>at</mi><mi>g</mi><mi>l</mi><mi>a</mi><mi>A</mi><mi>ABOUT</mi><mi>AT</mi><mo stretchy="false">)</mo></mrow></math><img file="00000022.jpg" he="6" wi="75" img-format="jpg" img-content="undefined" /></maths><maths id="" num="44"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000023.jpg" he="6" wi="38" img-format="jpg" img-content="undefined" /></maths>(2)

I_A and I_BThey are respectively the previous measure of the strength of the total current I (before change), and a new measure of the strength of the total current I (after change).

From (2) we obtain the following equation:

<maths id="" num="45"><math display="block"><mrow><mi>A</mi><mi>B</mi><mo>=</mo><msqrt><mrow><msubsup><mi>I</mi><mi>A</mi><mn>2</mn></msubsup><mo>+</mo><msubsup><mi>I</mi><mi>B</mi><mn>2</mn></msubsup><mo>-</mo><mn>2</mn><mo>×</mo><msub><mi>I</mi><mi>A</mi></msub><mo>×</mo><msub><mi>I</mi><mi>B</mi></msub><mo>×</mo><mi>cos</mi><mo stretchy="false">(</mo><msub><mi>ψ</mi><mi>B</mi></msub><mo>-</mo><msub><mi>ψ</mi><mi>A</mi></msub><mo stretchy="false">)</mo></mrow></msqrt></mrow></math><img file="00000004.jpg" he="8" wi="73" img-format="jpg" img-content="undefined" /></maths><maths id="" num="46"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000023.jpg" he="6" wi="38" img-format="jpg" img-content="undefined" /></maths><maths id="" num="47"><math display="block"><mrow /></math><img file="00000024.jpg" he="6" wi="3" img-format="jpg" img-content="undefined" /></maths>(3)

ψ_Aand ψ_AT They are, respectively, the former measure of the phase shift of the total current I and the phase shift of a new measure of the total current I.

According to a second mode of action, the computing device 15 determines the value of the force AB using equation (3).

Furthermore, we have the following relation:

P_B - P_A = <maths id="" num="48"><math display="block"><mrow><mi>U</mi><mo>×</mo><mi>A</mi><mi>B</mi><mo>×</mo><mi>sin</mi><mo stretchy="false">(</mo><msub><mi>ψ</mi><mn>1</mn></msub><mo stretchy="false">)</mo></mrow></math><img file="00000025.jpg" he="6" wi="29" img-format="jpg" img-content="undefined" /></maths><maths id="" num="49"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000023.jpg" he="6" wi="38" img-format="jpg" img-content="undefined" /></maths>(4)

P_A - Still full of power consumed by the electrical installation 1, ie a set of branches 4, as measured by the counter 6 to change. P_B a new total power consumption of the electric installation 1, as measured by the counter 6 after the change. U represents a measure of the total voltage across the terminals of the branches of Group 4.

From (4) we obtain the following equation:

<maths id="" num="50"><math display="block"><mrow><msub><mi>ψ</mi><mn>1</mn></msub><mo>=</mo><mi>arcsin</mi><mrow><mo>(</mo><mrow><mfrac><mrow><msub><mi>I</mi><mi>B</mi></msub><mo>×</mo><mi>cos</mi><msub><mi>ψ</mi><mi>B</mi></msub><mo>-</mo><msub><mi>I</mi><mi>A</mi></msub><mo>×</mo><mi>cos</mi><msub><mi>ψ</mi><mi>A</mi></msub></mrow><mrow><mi>A</mi><mi>B</mi></mrow></mfrac></mrow><mo>)</mo></mrow></mrow></math><img file="00000005.jpg" he="12" wi="66" img-format="jpg" img-content="undefined" /></maths><maths id="" num="51"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000023.jpg" he="6" wi="38" img-format="jpg" img-content="undefined" /></maths>(5)

According to a second mode of action, the computing device 15 determines the value of the angle ψ₁ using equation (5).

The ABS triangle shown in FIG. 6, we obtain the following relationship:

<maths id="" num="52"><math display="block"><mrow><mi>S</mi><msup><mi>A</mi><mn>2</mn></msup><mo>=</mo><mi>S</mi><msup><mi>B</mi><mn>2</mn></msup><mo>+</mo><mi>A</mi><msup><mi>B</mi><mn>2</mn></msup><mo>-</mo><mn>2</mn><mo>×</mo><mi>S</mi><mi>B</mi><mo>×</mo><mi>A</mi><mi>B</mi><mo>×</mo><mi>cos</mi><msub><mi>ψ</mi><mn>2</mn></msub></mrow></math><img file="00000026.jpg" he="6" wi="68" img-format="jpg" img-content="undefined" /></maths>(6)

From equation (6), we get the following equation:

<maths id="" num="53"><math display="block"><mrow><msub><mi>ψ</mi><mn>2</mn></msub><mo>=</mo><mi>arccos</mi><mrow><mo>(</mo><mrow><mfrac><mrow><msubsup><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow><mn>2</mn></msubsup><mo>+</mo><mi>A</mi><msup><mi>B</mi><mn>2</mn></msup><mo>-</mo><msubsup><mi>I</mi><mrow><mn>3</mn><mi>A</mi></mrow><mn>2</mn></msubsup></mrow><mrow><mn>2</mn><mo>×</mo><msub><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>×</mo><mi>A</mi><mi>B</mi></mrow></mfrac></mrow><mo>)</mo></mrow></mrow></math><img file="00000006.jpg" he="13" wi="51" img-format="jpg" img-content="undefined" /></maths><maths id="" num="54"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000023.jpg" he="6" wi="38" img-format="jpg" img-content="undefined" /></maths>(7)

In accordance with the second method steps, the computing device 15 determines the value of the angle ψ₂ using equation (7).

Furthermore, there is the following relationship

<maths id="" num="55"><math display="block"><mrow><mi>S</mi><mi>H</mi><mo>=</mo><mi>S</mi><mi>B</mi><mo>×</mo><mi>sin</mi><mo stretchy="false">(</mo><msub><mi>ψ</mi><mn>1</mn></msub><mo>+</mo><msub><mi>ψ</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow></math><img file="00000027.jpg" he="6" wi="40" img-format="jpg" img-content="undefined" /></maths><maths id="" num="56"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000028.jpg" he="6" wi="56" img-format="jpg" img-content="undefined" /></maths>(8)

From (8) we obtain the following equation:

<maths id="" num="57"><math display="block"><mrow><msub><mi>P</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>=</mo><mi>U</mi><mo>×</mo><msub><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>×</mo><mi>sin</mi><mo stretchy="false">(</mo><msub><mi>ψ</mi><mn>1</mn></msub><mo>+</mo><msub><mi>ψ</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow></math><img file="00000029.jpg" he="6" wi="47" img-format="jpg" img-content="undefined" /></maths><maths id="" num="58"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000028.jpg" he="6" wi="56" img-format="jpg" img-content="undefined" /></maths>(9)

According to a second mode of action, the computing device 15 uses the equation (9) for determining new individual power P_3B 4 in the branch in which the current I flows₃.

Of course, the formula used may have another shape different from the equations (3) and (5), (7) and (9), while remaining in the second mode of action, which has been explained above. For example, the equation (3), (5), (7) and (9) can be combined in the direction of reducing the formulas used. It should be noted that equation (3) may be included in the equation (5) in equation (7), while the equation (5) and (7) may be included in the equation (9).

Computing device 15 can also determine the phase shift ψ_3B the new current I₃That is, the current I₃ after the change, using the following relationship:

<maths id="" num="59"><math display="block"><mrow><msub><mi>ψ</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>=</mo><mi>π</mi><mo>/</mo><mn>2</mn><mo>-</mo><mo stretchy="false">(</mo><msub><mi>ψ</mi><mn>1</mn></msub><mo>+</mo><msub><mi>ψ</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow></math><img file="00000008.jpg" he="6" wi="39" img-format="jpg" img-content="undefined" /></maths><maths id="" num="60"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000028.jpg" he="6" wi="56" img-format="jpg" img-content="undefined" /></maths>(10)

Computing device 15 may also define individual previous power P_3AThat is, the power consumption to changes in branch 4, where the current I flows₃. To do this, it may use the following relationship:

R_3A= P_3B-(R_AT-R_A)<maths id="" num="61"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000023.jpg" he="6" wi="38" img-format="jpg" img-content="undefined" /></maths>(eleven)

Computing device 15 may also define a new individual reactive power Q_3BThat is, the reactive power after the change in the four branches, where the current I flows₃. To do this, it may use the following relationship:

<maths id="" num="62"><math display="block"><mrow><msub><mi>Q</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>=</mo><mi>U</mi><mo>×</mo><msub><mi>I</mi><mrow><mn>3</mn><mi>B</mi></mrow></msub><mo>×</mo><mi>cos</mi><mo stretchy="false">(</mo><msub><mi>ψ</mi><mn>1</mn></msub><mo>+</mo><msub><mi>ψ</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow></math><img file="00000030.jpg" he="6" wi="48" img-format="jpg" img-content="undefined" /></maths><maths id="" num="63"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000028.jpg" he="6" wi="56" img-format="jpg" img-content="undefined" /></maths>(12)

Computing device 15 may also identify the old individual reactive power Q_3AThat is, the reactive power before the change in the four branches, where the current I flows₃. To do this, it may use the following relationship:

Q_3A= Q_3B- (Q_B - Q_A)<maths id="" num="64"><math display="block"><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow><mtable><mtr><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd><mtd><mrow /></mtd></mtr></mtable></mrow></math><img file="00000031.jpg" he="6" wi="44" img-format="jpg" img-content="undefined" /></maths>(13)

Like the first method steps by using a numerical solution, the second mode of operation based on the trigonometric expansions gives two solutions which correspond to the points S and S 'in Fig. 5. These two solutions arise from the fact that the arcsine calculation in formula (5) can give a positive or negative value. Abnormal solution, corresponding to the point S ', is eliminated in the second mode of action, as it did in the first mode of action.

From the above description in the case of a single phase, the process steps 30 to determine the individual capacity can be easily extended to the case of electrical installations for multiphase currents. For clarity, their distribution in the case of electrical systems for multi-phase currents can not be described in further detail.

31 A method for determining an individual power branch is suitable in the case 4, which is equipped with a current detector or other means to detect the flow or current flow, and which has a fixed load impedance. In the example shown, the method 31 for determining the individual capacity for estimating individual power consumed by the load 5b. In this process 31, the individual capacity of four branches comprising 5b load change is calculated as equal to the total power consumption during a change in the branch 4 when the flow of current I₂ It detected after the change. Apparent power is the power consumed by all branches of 4. It is measured by the counter 6, the electric power consumption, or is derived from measurements made last. In the absence of the current I₂, The power consumed in the branch 4 having 5b load is considered zero.

32 A method for determining the power used in the individual case, the load impedance having unstable, which may gradually change. In the example shown, the method 32 for determining the power used by an individual to determine the individual power consumed by the load 5d. In this process 32, the individual power branch 4 having a load 5d, 9 meter measured the electric power consumption, or derived from measurements made by the latter.

Preferably, the electric power consumption of the counter 9 may be calibrated using measurements made by the counter 6 and consumption of electric power of the simplified calculation 41, which comprises a method 30 for determining the individual capacity. Calibration consumption meter 9 may be in the form of correction, the computing device 15 at the level of the computing device on the results of measurements, rather than at the level 9, the consumption meter. This calibration can be performed during the initial commissioning of the consumption meter 9 in the electrical installation, and then at regular intervals. Due to this, the consumption meter 9 may be less accurate, provided that it forms a true measure. In particular, the counter 9 consumption can be calibrated at the factory and be cheaper.

33 A method for determining an individual power branch is suitable in the case 4, which has a single fixed load impedance throughout the electrical system 1. In the example shown, the method 33 for determining the individual capacity for estimating individual power consumed by the load 5a. In this process 33, the individual capacity of four branches comprising 5a load is calculated as the change in total power equal to four branches set if this variation is positive and a is in the range of power which can consume 5a load. When the change in the total power has a negative sign and is in the range of a power, the power consumed in the branch 4 having 5a load is regarded as zero.

Individual power consumed in the branch 4 is calculated by integrating over the individual capacity, which has been evaluated or measured in this branch 4 one way 30-33. Integration of individual power time use history record power consumption changes in the branches 4.

According to one alternative of the invention, the electrical installation is an installation of one DC source is connected to power supply 2, which ensures a DC voltage. In this case the measuring and detecting devices respectively adapted, and step 42 is simplified. Of course, there is no phase shift to measure or otherwise determine. In a simplified step 42, the power consumed in the branch 4, in which the current I flows₃It is determined by measuring the strength of the current I₃ and measurement of the full supply voltage U of branches 4, as the product of one thing to another. Power in the branch 4, in which the current I flows₄It can be obtained in the same manner, so that the branch 4 may be equipped with one ammeter. 31 Method for determining the individual capacity is similar in the case of AC and DC. The same is true for the process 33 of determining individual power.

The invention is not limited to the embodiments described above. In particular, when used in the AC power supply amount, the invention is not limited to the case of single-phase alternating current, but instead may be implemented in electrical installations for multiphase currents. In addition, the invention encompasses both the average and high voltage and low voltage, even though the example described above relates to the field of low voltage.