Controller for a motor and a method of controlling the motor

ES 2 415 243 T3

DESCRIPTION

Controller for a motor and motor control procedure

BACKGROUND

[0001] The invention relates to a controller for a motor, and particularly, to a controller for a motor-operated pump.

[Οθ02] Occasionally in a pool, spa or similar fluid jet application, the main drain can become clogged with an object, such as a towel or pool toy. When this occurs, the suction force of the pump is applied to the clog and the object sticks to the drain. This is called suction entrapment. If the object substantially covers the drain (such as a towel covering the drain), the water is pumped out of the drain area of ​​the pump. Eventually if the pump runs dry, the seals burn out and the pump can be damaged.

[0003] Another type of trapping is referred to as mechanical trapping. Mechanical entrapment occurs when an object, such as a pool towel or toy, becomes entangled in the drain cover. Mechanical entrapment can also affect pump performance.

[0004] Various solutions have been proposed for mechanical and suction entrapment. For example, in newly built pools it is required to have two drains, so that if one of the drains becomes clogged, the other can still flow freely and vacuum trapping does not take place. This, however, does not help in existing pools, as adding a second drain to a pool from an inground drain is very difficult and expensive. Modern pool drain covers are also designed in such a way that objects cannot become entangled in the cover.

[0005] As another example, various manufacturers offer systems known as Safety Vacuum Release Systems (SVRS). SVRS often contain multiple layers of protection to help prevent both mechanical and suction entrapment. Most SVRS use hydraulic release valves that are placed in the suction zone of the pump. The valve is designed to release (open to atmosphere) if the vacuum (or pressure) within the drain pipe exceeds a set threshold, thereby releasing the obstruction. These valves can be very effective in releasing the suction developed under these circumstances. Unfortunately, it has several technical problems that have limited its use. The first problem is that the release valve generally needs to be mechanically adjusted for each pool. Even when properly adjusted, the valve can be prone to annoying plugging. The third problem is that the valve needs to be properly positioned in the suction zone of the pump. This makes installation difficult for the average homeowner.

[0006] US 2009290991 describes a motor control method that operates a pump apparatus of a jet fluid application. The pumping apparatus includes a pump having an inlet for receiving a fluid and an outlet for expelling the fluid, and the motor being coupled to the pump for operating said pump. The procedure includes motor control action to run the pump and monitor the operation of the pump. The act of monitoring includes monitoring a motor power, and determining whether the monitored power indicates an unwanted flow of fluid through the pump. The method further includes the act of controlling the motor to stop the operation of the pump when the determination indicates an unwanted flow rate of fluid through the pump if zero or other conditions occur.

[0007] Document US 2003106147 describes a Safety Vacuum Release System (SVRS) for swimming pools that monitors the vacuum level in a suction pipe and reverses the flow inside the suction pipe, when the vacuum level exceeds a predetermined level. Therefore, if a swimsuit becomes trapped in the suction outlet such as the main pool drain, the SVRS system not only releases the vacuum but also pushes the trapped swimsuit by suction. In response to a high level of vacuum, a vacuum monitoring device actuates an automatic valve, which reverses fluid communication between the inlet and outlet lines of the pump and the filter system. In this process, the suction pipe is converted from vacuum (negative pressure) to positive pressure. From there, the automatic valve system automatically resets the SVRS to the original setting or normal flow. The SVRS works without interrupting the operation of the pool's filtration system.

[0008] US6342841 describes an inlet blockage detection system with a microcontroller that establishes normal operation and suction and vacuum time operation profiles for a swimming pool circulation pump. A user slightly adjusts the vacuum levels within a predetermined range to store a vacuum profile envelope within memory for vacuum operation. A comparator compares the actual time inputs from the start and pump suction to the normal operating envelope during normal operation of the circulating pump. The comparator compares real-time inputs of the vacuum direction and the time since the start when the controller is in vacuum mode with the vacuum envelope stored in memory. Lights flash in sequence to indicate selected vacuum levels, and the levels are displayed on an alphanumeric display screen. A reset switch is also located within the control lock box to allow the system to automatically close the power relay and restart the pump after power outages.

ES 2 415 243 T3

SUMMARY

[0009] The invention is precisely defined in method claim 1. The dependent claims list advantageous embodiments of the invention.

[θ0ΐΟ] In one embodiment, the invention provides a controller for a motor that monitors motor input power and / or pump inlet side pressure (also referred to as pump inlet side vacuum). This monitoring helps determine if a drain clog is occurring. If drainage or pumping is substantially restricted in the suction zone of the pump, the pressure on that side of the pump increases. At the same time, since the pump is no longer pumping fluid, the input power to the motor drops. Any of these conditions can be considered a fault and the engine is shut down. It is also foreseen that if the pool filter becomes clogged, the input power of the pump will also drop and the motor will also turn off.

Other features and aspect of the invention will become apparent upon consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

[0012] Figure 1 is a schematic representation of a jet spa incorporating the invention.

[0013] Figure 2 is a block diagram of a controlled first suitable for use in the jet spa of Figure 1.

Figures 3A and 3B are electrical diagrams of the first controller shown in Figure 2.

[0015] Figure 4 is a block diagram of a second controller suitable for use in the jet spa shown in figure 1.

Figures 5A and 5B are electrical diagrams of the second controller shown in Figure 4.

[0017] Figure 6 is a block diagram of a third controller suitable for use in the jet spa shown in Figure 1.

[0018] Figure 7 is a block diagram of a fourth controller suitable for use in a jet spa shown in Figure 1.

[0019] Figure 8 is a graph indicating the relationship between nominal slip and normalized power of motor 145.

[0020] Figure 9 is a block diagram of a fifth controller capable of being used in a jet spa shown in Figure 1.

Figure 10 is a block diagram of a sixth controller suitable for use in the jet spa shown in Figure 1.

DETAILED DESCRIPTION

Before explaining in detail that any embodiment of the invention, it should be understood that the invention is not limited in its applications to the details of construction and configuration of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it should be understood that the phraseology and terminology is used herein for the purpose of description and should not be considered limiting. The use of "including", "comprising" or "bearing" and variations thereof in this document is understood to encompass the articles related thereto and equivalents thereof as well as additional elements. Unless otherwise specified or limited, the terms "mounted", "attached", "supported" and "attached" and their variations are widely used and include directly and indirectly mounts, connections, brackets and couplings. Furthermore "connected" and "coupled" are not restricted to mechanical or physical connections or couplings.

[0023] Figure 1 schematically represents a jet spa 100 incorporating the invention. However, the invention is not limited to jet spa 100 and can be used in other jet fluid systems (eg, swimming pools, hot tubs, whirlpools, etc.). It is also envisioned that the invention may be used in other applications (eg fluid pumping applications).

[0024] As shown in Figure 1, the spa 100 includes a vessel 105. As used herein, the vessel 105 is a container such as a tub, swimming pool, tank, or tub that contains a charge. The cargo includes a fluid, such as chlorinated water, and can include one or more occupants or articles. The spa further includes a fluid drive system 110 coupled to vessel 105. The fluid drive system 110 includes a drain 115, a pumping apparatus 120 having an inlet 125 coupled to the drain and an outlet 130, and a return conduit 135 coupled to the outlet 130 of pumping apparatus 120. The pumping apparatus Pumping 120 includes a pump 140, a motor 145, coupled to the pump 140, and a controller 150 to control the motor 145. For the construction described herein, pump 140 is a centrifugal pump and motor 145 is an induction motor (e.g. capacitor start motor, induction management capacitor, split phase induction motor, three phase induction motor, etc. .). However, the invention is not limited to this type of pump or motor. For example, a brushless direct current (DC) motor can be used in a different pumping application. For other constructions, a jet fluid system can include multiple drains, multiple returns, or even multiple fluid drive systems.

[0025] Referring again to Figure 1, vessel 105 contains a fluid. When fluid drive system 110 is activated, pump 140 causes fluid to travel from drain 115, through pump

ES 2 415 243 T3

140, spurt into cup 105. This pumping operation occurs when controller 150 provides power to motor 145 in a controlled manner, which results in mechanical movement by motor 145. Coupling of motor 145 (for example , direct coupling or indirect coupling via a connection system) to pump 140 results in motor 145 mechanically operating pump 140 to drive fluid. The operation of the controller 150 can be through an operating interface, which can be as simple as a power switch.

[0026] Figure 2 is a block diagram of a first construction of controller 150, and Figures 3A and 3B are electrical schematics of controller 150. As shown in Figure 2, controller 150 is electrically connected to the power source. energy 155 and to the motor.

With reference to Figures 2 and 3B, controller 150 includes a power supply 160. Power supply 160 includes resistors R46 and R56; capacitors C 13, C 14, C16, C 18, C 19, and C20; diodes D10 and D1; Zener diodes D10 and D1; a power supply controller U7; a U6 regulator; and an optical switch U8. Power supply 160 receives power from power source 155 and provides adequate direct voltage (eg, -5 VDC and -12 VDC) to operate the controller.

[0028] For the controller 150 shown in Figures 2 and 3A, said controller 150 monitors the input power of the motor and the input pressure of the pump zone 140, to determine if a drain blockage has occurred. If in the drain 115 the pumping is plugged on the side of the pump 140, the pressure on that side of the pump 140 increases. At the same time, since the pump 140 is no longer pumping water, the input power to the motor 145 drops. If either of these circumstances occurs, the controller 150 declares a fault, the engine 145 shuts down, and the fault indication lights come on.

[0029] A voltage sensing and averaging circuit 165, a current sensing and averaging circuit 170, a line voltage sensing circuit 175, a triac (alternating current triode) voltage sensing circuit 180, and the micro-controller 185, perform input power supervision. The voltage sensing and averaging circuit 165 includes resistors R34, R41, and R42; a diode D9; a capacitor C110; and an operational amplifier U4A. The voltage sensing and averaging circuitry rectifies the voltage from power source 155 and then performs a direct current average of the rectified voltage. The DC media is then fed to the microcontroller 185.

[0030] An example of the averaging and current sensor circuit 170 is shown in Figure 3. The averaging and current sensor circuit 170 includes a transformer T1 and a resistor R45, which act as a current sensor that detects the current applied to the motor. The current sensing and averaging circuit also includes resistors R25, R26, R27, R28, and R33; diodes D7 and D8; a capacitor C9; and operational amplifiers U4C and U4D, which rectifies and averages the value that represents the detected current. For example, the resulting scale of the current sensing and averaging circuit 170 may be a negative value between zero and five volts, corresponding to an RMS value between zero and twenty five amps. The average DC is then fed to microcontroller 185.

[0031] An example of a line voltage detection circuit 175 is shown in FIG. 3A. Line voltage detection circuit 175 includes resistors R23, R24 and R25; a diode D5; a Zener diode D6; a transistor Q6; and NAND gate U2B. Line voltage sense circuit 175 includes a zero crossing detector that generates a pulse signal. The pulse signal includes pulses that are generated each time the line voltage crosses zero volts.

[0032] Another example of a triac voltage sense circuit 180 is shown in FIG. 3A. The triac voltage sense circuit 180 includes resistors R1, R5, and R6; a diode D5; a Zener diode D1; a transistor Q1; and a NAND U2A gate. Triac voltage sense circuit 180 includes a zero crossing detector that generates an impulsive signal. The impulse signal includes pulses that are generated each time the line voltage crosses zero volts.

[0033] An example of a microcontroller 185 that can be used with the invention is a Motorola brand microcontroller, model number MC68HC908QY4CP. Microcontroller 185 includes a processor and memory. Memory includes software instructions that are read, interpreted, and executed by the processor to manipulate data or signals. The memory also includes memory for storing data. Micro-controller 185 may include other circuitry (for example, an analog-to-digital converter) necessary to operate micro-controller 185. In general, micro-controller 185 receives inputs (signals or data), executes instructions for software to analyze the inputs and generate outputs (signal or data) based on the analyzes. Although the microcontroller 185 is shown and described, the invention can be implemented with other devices, including a variety of integrated circuits (e.g., application-specific integrated circuit), programmable devices, and / or discrete devices, as should be apparent to the public. a person of normal skill in the art. Additionally, it is envisaged that the micro-controller 185 or similar circuit can perform the function of some of the other circuits described (eg, circuitry 165 to 180) above the controller 150. For example, the micro-controller 185, in some construction, it can receive a detected voltage or a detected current and determine an average voltage, an average current, the zero crossing of the detected voltage and / or the zero crossing of the detected current.

The micro-controller 185 receives the signals representing the average voltage applied to the motor 145, the average current through the motor 145, the zero crossing of the motor voltage, and the zero crossing of the motor current. . From the zero crossing, the microcontroller 185 can determine a power factor. The power factor can be calculated using known mathematical equations or by using a look-up table based on mathematical equations. The micro-controller 185 can then calculate a power with the averaged voltage, the averaged current, and the power factor as known. As we will discuss later, the

ES 2 415 243 T3 micro-controller 185 compares the power to a power calibration value to determine if a fault condition is present (eg due to obstruction).

Referring again to Figures 2 and 3A, the pressure (or vacuum) sensing circuit 190 and the microcontroller 185 monitor the pressure on the inlet side of the pump. In FIG. 3A, an example of the pressure sensing circuit 190 is shown. The pressure sensing circuit 190 includes resistors R16, R43, R44, R47, and R48; capacitors C8, C12, C15, and C17; a Zener diode D4, a piezoresistive sensor U9, and operational amplifiers U4-B. Piezoresistive sensor U9 is welded to the suction side of pump 140. Pressure sensing circuit 190 and microcontroller 185 translate and amplify the signal generated by piezoresistive sensor U9 into a value representing the inlet pressure. As will be discussed later, the microcontroller 185 compares the resulting pressure value with the pressure calibration value to determine if a fault condition is present (eg, due to an obstruction).

[0036] Calibration of controller 150 occurs when the user activates calibration switch 195. An example of a calibration switch is shown in FIG. 3A. The calibration switch 195 includes a resistor R18 and a Hall effect switch U10. When a magnet passes Hall effect switch U10, the switch generates a signal provided to microcontroller 185. Upon receiving the signal, the micro-controller 185 stores the signal calibration value for the pressure sensor by acquiring the current pressure, and stores a power calibration value for the motor by calculating the present power.

[0037] As noted above, controller 150 provides power to motor 145 in a controlled manner. Referring to Figure 2 and Figure 3A, controller 150 includes retrigger pulse generator circuit 200. The re-trigger pulse generator circuit 200 includes a resistor R7, a capacitor C1, and a pulse generator U1A, and outputs a value to the NAND gate U2D, when the re-trigger pulse generator circuit 200 receives a signal having a pulse frequency higher than the set frequency determined by resistor R7 and capacitor C1. The NAND gate U2D also receives a signal from the ignition delay circuit 205, which prevents a spurious trip of the relay during start-up. The output of the NAND gate U2D is provided to the relay control circuit 210. The relay control circuit 210, shown in Figure 3A includes resistors R19, R20, R21, and R22; a capacitor C7; a diode D3; e Q5 and Q4 switches. Relay control circuit 210 controls relay K1.

The micro-controller 185 also provides an output to the triac controller circuit 215, which controls the triac Q2. As shown in Figure 3A, the triac driver circuit 215 includes resistors R12, R13, and R14, a capacitor C11, and a switch Q3. For current to flow to the motor, relay K1 needs to close and triac Q2 needs to be activated / tripped.

Controller 150 also includes a thermal switch S1 to monitor the triac heatsink, a power supply supervisor 220 to monitor the voltages produced by power supply 160, and a plurality of LEDs DS1, DS2, and DS3 to provide information to the user. In the construction shown, a green DS1 LED indicates power applied to controller 150, a red DS2 LED indicates that a fault has occurred, and a third DS3 LED is a flashing LED to indicate that micro-controller 185 is operating. Of course, other interfaces can be used to provide information to the operator.

[0040] The normal sequence of events for a procedure of operation of the controller 150 is described below. When the fluid drive system 110 is initially activated, the system 110 may have to draw air from the pump suction side and cause it to fluid circulates slightly. This "prime" period usually lasts only a few seconds, but can last a minute or more when there is a lot of air in the system. After priming, the water circulates, the suction zone applies pressure, and the motor input power remains relatively constant. It is during this period of normal operation that the circuit is effective in detecting an abnormal event. The micro-controller 185 includes a start-stop function that prevents the supervisor from detecting an abnormal condition during the priming period.

[0041] After the system 110 is running smoothly, the spa operator can calibrate the controller 150 to the current operating conditions of the spa. The calibration values ​​are stored in the memory of the micro-controller 185, and will be used as the basis for the supervision of the spa 100. If for any reason the operating conditions of the spa change, the controller 150 can be re-calibrated by the operator. . If at any time during normal operation, however, the suction zone pressure increases substantially (for example 12%) above the pressure set value, or the motor input power drops (12%) below the power calibration value, the pump shuts down, lighting a fault indicator.

[0042] As discussed above, controller 150 measures motor input power, and not just motor power factor or input current. Some motors have electrical characteristics such that the power factor remains constant while the motor is without load. Other motors have an electrical characteristic such that the current remains relatively constant when the pump is without load. However the input power goes down in pump systems when the drain becomes clogged, and water circulation is impeded.

[0043] The averaging and voltage detector circuit 165 generates a value representing the mean power line voltage while the averaging and current detector circuit 170 generates a value representative of the mean motor current. The motor power factor is derived from the difference between line power zero crossing events and triac zero crossing events. The line voltage sensing circuit 175 provides a signal representing the zero crossing of the line power. The triac zero crossing occurs at the zero crossing of the control current. The triac voltage sensing circuit 180 provides a signal representing the triac's zero crossings. The time difference of the zero crossing events is used to

ES 2 415 243 T3 look up the motor power factor from a table stored in the micro-controller 185. This data is then used to calculate the motor input power using equation e1.

[el] Vmean x Imean x PF = Motor_Input_power

[0044] The calculated motor_input_power is then compared to the calibrated value to determine if a fault has occurred. If a fault has occurred, the engine is shut down and the fault is turned on.

[0045] Another aspect of controller 150 is a "soft start" feature. When the typical pump motor 145 is turned on, it quickly accelerates to full speed. Sudden flushing creates an increase in vacuum on the inlet side of pump 140 and increases pressure on the discharge zone side of pump 140. Increased vacuum can spuriously hinder the hydraulic release valves of spa 100. Increased pressure at the outlet can also create water hammer which is detrimental to the pumping / piping and especially detrimental to the filter (if present). The soft start feature slowly increases the voltage applied to the motor over a period of time (for example two seconds). By gradually increasing the voltage, the motor accelerates more smoothly, avoiding the pressure / vacuum peak in the pumping / piping is avoided.

[0046] Another aspect of controller 150 is the use of a redundant detection system. By observing both the inlet side pressure of the pump and the input power of the motor, should a fault occur in either of them, the remaining detector could still shutdown the system 110.

[0047] Redundancy is also used for power switches that cut off power to the motor. Both a relay and a triac are used in series to perform this function. In this way, a failure in any of the components will still leave a switch to turn off the motor 145. As an additional safety feature, the proper operation of both switches is checked by the micro-controller 185 each time the motor is started. .

[0048] Another aspect of controller 150 is the use of various monitoring functions to verify that all circuits are operating as intended. These functions may include checking if the input voltage is in a reasonable range, checking if the motor current is in a reasonable range, and checking if the suction side pressure is in a reasonable range. For example, if the motor current exceeds 135% of the calibrated value, the motor can be considered overloaded and is shut down.

[0050] As discussed above, controller 150 also monitors the power supply 160 and the temperature of the triac heat sink. If either is out of proper range, controller 185 may shut down motor 145 and declare a fault. Controller 150 also supervises triac and line voltage detector circuits 175 and 180 respectively. If pulses passing through zero are received by any of these circuits at a frequency less than a defined period of time (for example, every 80 milliseconds), the motor shuts down.

[0051] Another aspect of controller 150 is that micro-controller 185 must provide pulses at a frequency greater than a set frequency (determined by the time constant of resistor R7 and C1) to close relay K1. If pulse generator U1A is not fired at the proper frequency, relay K1 opens and the motor shuts down.

Thus, the invention provides, among other things, a controller for a motor operating a pump. While numerous aspects of the controller 150 have been discussed above, not all of the aspects and features discussed above are required for the invention. For example, controller 150 can be modified to monitor only motor input power or suction side pressure. Additionally, other features and features can be added to the controller 150 shown in the figures. For example, some of the features to be discussed later for controller 150a may be added to controller 150.

[0053] Figure 4 is a block diagram of a second construction of controller 150a, and Figures 5A and 5B are an electrical schematic of controller 150a. As shown in Figure 4, controller 150a is electrically connected to a power source 155 and motor 145.

[0054] With reference to Figures 4 and 5B, controller 150a includes a power supply 160a. Power supply 160a includes resistors R56 and R76, capacitors C16, C18, C20, C21, C22, C23, and C25; diodes D8, D10 and D11; Zener diodes D6, D7 and D9; a power supply controller U11; a U9 regulator; inductors L1 and L2, surge suppressors MOV 1 and MOV 2, and optical switch U10. Power source 160a receives power from power source 155 and provides adequate direct voltage (eg +5 VDC and +12 VDC) to operate controller 150a.

[0055] In controller 150a shown in Figures 4, 5A and 5B, said controller 150a monitors the input power of the motor to determine if a drain clog has occurred. As in the previously disclosed construction, if the drain 115 or (the) pump / pipes are (are) stuck on the suction side of the pump 140, the pump 140 will no longer pump water. And the input power to the motor goes down. If this condition occurs, controller 150a declares a fault, engine 145 shuts down, and a fault indicator lights.

[0056] A voltage sensing and averaging circuit 165a, a current sensing and averaging circuit 170a, and the micro-controller 185a perform input power supervision. An example of a voltage sensing and averaging circuit 165a is shown in FIG. 5A. The Voltage Detector and Average Circuit 165^to, includes resistors R2, R31, R34, R35, R39, R59, R62, and R63; diodes D2 and D12; a capacitor C 14; and U5C and U5D operational amplifiers. The voltage sensing and averaging circuit 165a rectifies the voltage of the power source 155 and then performs a direct current averaging of the rectified voltage. The average DC is then

ES 2 415 243 T3 fed to micro-controller 185a. The medium circuit and voltage detector 165a, also includes resistors

R22, R23, R27, R28, R30, and R36; a capacitor C27; and a comparator U7A; that provide the voltage waveform signal (eg as a zero crossing detector) to microcontroller 185a.

[0057] An example of the current sensing and averaging circuit 170a is shown in FIG. 5B. The averaging and current detector circuit 170a includes a transformer T1 and a resistor R53, which acts as a current detector that detects the current applied to the motor 145. The 170a current sensing and averaging circuit also includes resistors R18, R20, R21, R40, R43, and R57; diodes D3 and D4; capacitor C8; and operational amplifiers U5A and U5B, which rectify and average the value represented by the current detector. For example, the scale resulting from the 170a current sensing and averaging circuit may be a positive value of or to five volts, corresponding to an RMS value of zero to twenty-five amps. The resulting average DC is then fed to microcontroller 185a. The averaging and current detector circuit 170a also includes resistors R24, R25, R26, R29, R41, and R44; a capacitor C11; a comparator U7B; which provides the sign of the current waveform (eg, acts as a zero-crossing detector) to microcontroller 185a.

[0058] An example of a microcontroller 185a that can be used with the invention is a Motorola brand microcontroller model number MC68HC908QY4CP. Similar to what has been discussed for the previous construction, the microcontroller 185a includes a processor and memory. Memory includes software instructions that are read, interpreted, and executed by the processor to manipulate data or signals. The memory also includes data storage memory. Micro-controller 185a may include other circuitry (eg, analog-to-digital converters) necessary to operate micro-controller 185a and / or may perform the function of any of the other circuits described above for controller 150a. In general, the microcontroller 185a receives inputs (signals or data), executes software instructions to analyze the input, and generates outputs (signals or data) based on the analyzes.

[0059] The micro-controller 185a receives the signals representing the average voltage applied to the motor 145, the average current through the motor 145, the zero crossings of the motor voltage, the zero crossings of the motor current. From the zero crossings, the microcontroller 185a can determine a power factor and a power as described above. The micro-controller 185a can then compare the calculated power to a power calibration value to determine if the fault condition is present (eg, due to an obstruction).

[0060] Calibration of controller 150a occurs when the user activates a calibration switch 195a. An example of calibration switch 195a is shown in the figure. 5A, which is similar to the calibration switch 195 shown in the figure. 3A. Of course, other calibration switches are possible. In one method of operating the calibration switches 195a, a calibration fob needs to be set close to the switch 195a when the controller 150a receives initial power. After removing the magnet and cyclic power, controller 150a goes through prime mode and enters an automatic calibration mode (discussed later).

Controller 150a provides power to motor 145 in a controlled manner. Referring to Figures 4 and 5A, controller 150a includes a re-trigger pulse generator circuit 200a. The re-trigger pulse generator circuit 200a, includes resistors R15 and R16, capacitors C2 and C6, and pulse generators U3A and U3B, and outputs a value to the relay control circuit 210a, when the retrigger pulse generator circuit 200a receives a signal that has a pulse frequency greater than a set frequency determined by resistors R15 and R16, and capacitors C2 and C6. The re-trip pulse generators U3A and U3B also receive a signal from the ignition delay circuit 205a, which prevents spurious activation of the relay during startup. The relay control circuit 210a shown in Figure 5A includes resistors R1, R3, R47, and R52; a capacitor C7; diodes D1 and D5; e Q1 and Q2 switches. Relay control circuit 210a controls relay K1 and K2. For current to flow to the motor, both relays K1 and K2 need to close.

Controller 150a further includes two voltage detectors 212a and 214a. The first voltage detector 212a includes resistors R71, R72, and R73; a capacitor C26; a diode D14; and a Q4 switch. The first voltage detector 212a senses when voltage is present across relay K1, and verifies that the relays are working properly before allowing the motor to run. The second voltage detector 214a includes resistors R66, R69, and R70; a capacitor C9; a diode D13; and a Q3 switch. The second voltage detector 214a detects whether a two-speed motor is being operated in high or low speed mode. The motor input power step values ​​are set according to the speed at which the motor runs. It is also envisioned that controller 150a can be used with a single speed motor without second voltage detector 214a (eg, controller 150b shown in Figure 6).

Controller 150a also includes a room thermal sensor circuit 216a to monitor the operating temperature of controller 150a, a power supply supervisor 220a to monitor the voltage produced by power supply 160a, and a plurality of DS1 LEDs. and DS3 to provide information to the user. In the construction shown, a green DS2 LED indicates power applied to controller 150a, a red DS3 LED indicates that a fault has occurred. Of course, other interfaces can be used to provide information to the operator.

[0064] Controller 150a further includes a cleaning mode switch 218a, which includes switch U4 and resistor R10. The cleaning mode switch can be actuated by an operator (for example maintenance personnel) to deactivate the power monitoring function described in this for a period of time (for example 30 minutes so that maintenance personnel can clean the bowl 105). Additionally, the red LED DS3 can be used to indicate that controller 150a is in cleaning mode. After the period of time, controller 150a returns to normal operation. In some constructions, maintenance personnel

ES 2 415 243 T3 may actuate the cleaning mode switch 218a for the controller 150a to exit the cleaning mode before the time period has been completed.

[0065] In another construction, the operator can determine a desired period of time for the controller 150a to operate in cleaning mode. For example, maintenance personnel may actuate the cleaning mode switch 218a a predefined number of times to indicate a desired length of time for the controller 150a to operate in the cleaning mode. In some cases when relatively low maintenance of the bowl 105 is required, the operator may actuate the cleaning mode switch 218a to operate in the cleaning mode for one hour, for example. The red LED DS3 can be used to visually indicate the amount of time maintenance personnel have programmed the controller 150a to operate in cleaning mode.

[0066] In some cases, it may be desirable to disable the power monitoring function for reasons other than performing bowl cleaning operations 105. Such cases will be indicated as off mode, disabled mode, unprotected mode or the like. Regardless of the name, this latter mode of operation may be at least in part characterized by the instructions defined under the cleaning mode operation above. In addition, when it comes to cleaning mode and its operation, the discussion also applies to the latter modes to deactivate the power monitoring function and vice versa.

[0067] The normal sequence of events for an operating procedure of controller 150a is described below, some of which are similar to the operating procedure of controller 150. When fluid drive system 110 is initially activated, system 110 You may have to draw air from the pump suction side (discussed above) and circulate the fluid to flow smoothly (indicated as a normal operating period). It is during this period of normal operation that the circuit is effective in detecting an abnormal event.

[0068] After powering up the system, the system 100 may enter a prime period. The priming period may be preset for a duration of time (eg a duration of 3 minutes), or for a duration of time determined by a detected state. After the prime period, the system 110 enters the normal period of operation. Controller 150 may include instructions to perform an automatic calibration to determine one or more calibration values ​​after a first power-up of the system. An example of a calibration value is a power calibration value. In some cases, the power calibration value is stored in the memory of the micro-controller 185, and will be used as a basis for monitoring the vessel 105.

[0069] If for any reason, the operating conditions of the container 105 change, the controller 150a can be re-calibrated by the operator. In some constructions, the operator actuates the calibration switch 195a to erase one or more calibration values ​​stored in the memory of the micro-controller 185. The operator then turns off the system 110, in particular the motor 145, and performs the power on of the system. . System 110 initiates the automatic calibration process as discussed above to determine one or more new calibration values. If at any time during normal operation, the monitored power varies from the power set value (for example, varies by 12.5% ​​from a window above the power set value), the engine 145 will shut down and an indicator will turn off. fault will light up.

[0070] In one construction, the automatic calibration instructions include not monitoring the power of the engine 145 during the ignition period, generally preset for a duration of time (eg 2 seconds), after the system is turned on. In the case when the system 110 is operated for the first time, the system 110 enters the priming period, after completing the start period, and the power of the motor 145 is monitored to determine the power calibration value. As noted above, the power calibration value is stored in the memory of the micro-controller 185. After the completion of the 3 minute prime period, the system 110 enters the normal operating period. On subsequent system power-ups, the monitored power is compared to the power calibration value stored in the memory of the micro-controller 185, memorized during the calibration period. More specifically, the system 110 enters the normal period of operation when the monitored power rises above the power set value during the priming period. In some cases, the monitored power does not rise above the power calibration value within 3 minutes of the prime period. As a consequence, the engine 145 is shut down and a fault indicator is lit.

[0071] In other constructions, the autocalibration prime period may include a longer preset duration of time (eg 4 minutes) or the adjustable duration of time capability. Additionally, controller 150a may include instructions, controller 150a may include instructions to perform signal conditioning operations at the supervised power. For example, controller 150a may include instructions to perform IIR (infinite impulse response) filtering to condition the monitored power. In some cases, IIR filtering can be applied to the monitored power during the priming period and the normal operating period. In other cases, IIR filtering can be applied to the monitored power after determining the power calibration value after the prime period.

Similar to controller 150, controller 150a measures motor input power, and not just motor power factor or input current. However, it is envisioned that controllers 150 and 150a may be modified to monitor other motor parameters (eg, motor current only, motor power factor only, or motor speed). But the motor input power parameter is preferred for controller 150a to determine if the water is clogged. It is also envisioned that controller 150a may be modified to monitor another parameter (eg, suction side pressure) of system 110.

[0073] For some constructions of controller 150a, micro-controller 185a monitors the power of

ES 2 415 243 T3 input of the motor for an over-power state in addition to an under-power state. Monitoring for an over-power condition helps reduce the possibility that controller 150a has been incorrectly calibrated, and / or also helps detect when the pump is overloaded (eg, the pump is driving too much fluid).

[0074] The averaging and voltage detector circuit 165a, generates a value representing the averaged power line voltage, while the averaging and current detector circuit 170a, generates a value representative of the mean motor current. The motor power factor is derived from the difference between the sign of the voltage signal and the sign of the current signal. The time difference is used to find the motor power factor from a table stored in the micro-controller 185a. The averaged power line voltage, mean motor current, and motor power factor are then used to calculate motor input power using equation e1, as discussed above. The calculated motor input power is then compared to the calibrated value to determine if a fault condition has occurred. If a fault condition has occurred, the engine is shut down and the fault indicator is lit.

Redundancy is also used for the power switches of the controller 150a. Two relays K1 and K2 are used in series to do this function. In this way, a failure in any of the components will still leave a switch to turn off the engine 145. As an additional safety feature, proper operation of both switches is checked by microcontroller 185a each time the engine is started through relay voltage sensing circuit 212a.

[0076] Another aspect of controller 150a is the use of various monitoring functions to verify that all circuits function as intended. These functions may include verifying if the input voltage is within a reasonable range (for example 85 to 135 V alternating current [AC], or 175 to 255 V alternating current), and verifying, if the motor current is within a reasonable range (5% to 95% of range). Also, if the motor current exceeds 135% of the calibrated value, the motor can be considered overloaded and is shut down.

[0077] Controller 150a also monitors the power supply 160a and ambient temperature of controller circuitry 150a. If either is out of proper range, controller 150a may shut down motor 145 and declare a fault. Controller 150a also monitors the sign of the power line voltage and the sign of the motor current. If the zero-passing pulses that result from this monitoring are at a frequency less than a defined period of time (eg every 30 milliseconds), the motor shuts down.

[0078] Another aspect of controller 150a is that micro-controller 185a provides pulses with a frequency greater than a set frequency (determined by re-trigger pulse generator circuits) to close relay K1 and relay K2. If pulse generators U3A and U3B are not activated at the proper frequency, relays K1 and K2 open and the motor shuts down.

[0079] Another aspect of some construction of controller 150a is that micro-controller 185a includes an automatic reset feature, which can help recognize spurious clogs (eg due to an air bubble in fluid drive system 110.) For this aspect, the micro-controller 185a, after detecting a fault and turning off the motor, waits a period of time (for example one minute), to reset, and try to start the pump. If controller 150a cannot successfully start the pump after a defined number of attempts (for example 5), microcontroller 185a hangs until it is turned off and restarted. The micro-controller 185a can further be programmed to clear the fault history when the pump operates normally for a period of time.

[0080] The micro-controller 185a may include a start-stop function that prevents the supervisor from detecting an abnormal state during the priming period, thus preventing unnecessary spurious firing. In a specific procedure of operation, the microcontroller 185a initiates a stop state after start, but monitors the input power of the motor after start. If pump 140 is priming, the input is usually low. Once the input power falls within a monitoring window (for example within 12.5% ​​above or below the power calibration value) and remains there for a period of time (for example two seconds), the micro-controller 185 ceases the stop state and enters normal operation even if the pump is not fully primed. This feature allows controller 150a to perform normal supervision as soon as possible, while reducing the risk of spurious firing during the priming period. For example, a full prime event can last two to three minutes after controller 150a has been turned on. However, when the motor input power has entered the monitoring window, the suction force 115 is sufficient to pick it up. By allowing the controller to enter run mode at this point, the risk of a suction event is greatly reduced through the remaining portion of the prime period. Therefore, the just-described operating procedure for cessation of the stopped state provides a higher protection efficiency than the programmed start-stop.

[0081] While numerous aspects of controller 150a have been discussed above, not all aspects and functions discussed above are required for the invention. Additionally, other features and functions can be added to the controller 150a shown in the figures.

[0082] As previously indicated, the micro-controllers 185, 185a, can calculate an input power from parameters such as average voltage, average current, and power factor. Microcontrollers 185 and 185a then compare the calculated input power to the power calibration heat to determine when a fault condition is present (eg, due to a plug).

In the construction shown in Figure 7, a sensor 300 is coupled to motor 145 to detect a characteristic of motor 145, such as motor speed. In other constructions, sensor 300 can detect other characteristics of motor 145. Controller 150c includes micro-controller 185b that receives at least one signal from sensor 300 indicative of motor speed. In the construction shown in figure 7, the micro

ES 2 415 243 T3 controller 185b can use motor speed and measured parameters of motor 145 to determine power output. Microcontroller 185b may also monitor output power to determine if a fault condition is present in a similar way to previous constructions (e.g. microcontrollers 185,

185a) using input power.

[0084] Figure 8 shows the power output of an exemplary motor 145 as a function of slip (horizontal axis) and normalized power (vertical axis). Referring to Figures 7 and 8, line 302 is indicative of the relationship between slip, which is a function of engine speed 145, and normalized power. In the illustrated construction, mark A indicates a slip of 0.081 at a normalized power ratio of 1, and mark B indicates a slip of 0.071 at a normalized power ratio of 0.9. Microcontroller 185b detects motor speed from sensor 300 and determines slip using formulas known to those skilled in the art. A 12% slip drop (for example from 0.081 at mark A to 0.071 at mark B) is determined to be representative of a 10% reduction in power output from engine 145. Thus, by monitoring the speed of the motor, the controller 150c can detect a fault condition and stop the operation of the motor 145 in accordance with the procedures described above. It should be understood that the information shown in figure 8 corresponds to a particular engine and that other engines may have different characteristics.

In another construction shown in Figure 9, controller 150d includes voltage averaging and detector circuit 165a, similar to that shown in Figures 4 and 6, feeding a DC voltage average to a microcontroller 185c, at least one certain normalized input voltage value. Under relatively normal operating conditions, the normalized input voltage is determined to be substantially constant at 1 unit and the slip is monitored to determine a failure state similar to that of the construction shown in Figure 7. In the construction shown in Figure 9, other than normal operating conditions can be determined by the change in value of the normalized input voltage. More particularly, the micro-controller 185c can adjust the slip in which the fault state is determined from the determined values ​​of the normalized input voltage using e2.

<img file="ES2415243T3_D0001.tif" />

Where Stp is the new displacement at which a fault condition is determined, Scal is the calibrated slip at a normalized voltage equal to 1, Vcal is the normalized calibrated voltage (generally a value of 1), and Vmeas is the normalized measured voltage. indicative of at least one operating state other than normal. [0086] A particular example where the normalized stress is determined to be 0.8, the slip value for a failure state is calculated using equation e2 to a new value of about 0.111. For this particular example, a decrease in slip of 12% is representative of an approximate decrease in normalized power of 7.5%. In another example, where the normalized stress is determined to be 1.2, the slip value for a fault condition can be calculated to a new value of 0.049. A 12% decrease in slip is representative of an approximate 12.5% ​​decrease in normalized power. For these two examples, a new equation e3 can be experimentally determined to better approximate the 12% drop to a 10% drop in normalized power.

<img file="ES2415243T3_D0002.tif" />

It should be understood that e3 is applicable to the motor with the characteristics shown in figure 8. Other motors require the same type of experimentation to determine a similar equation.

[0087] In another construction shown in Figure 10, controller 150e includes current sensing and averaging circuitry 170a, similar to that of Figures 4 and 6, at least for detecting current through motor 145. In the In the construction shown in Figure 10, microcontroller 185d uses motor speed, sensed current, and a set of calculation parameters previously programmed into microcontroller 185d to determine motor 145 output power. It is also possible that the calculation parameters, used by the micro

ES 2 415 243 T3 controller 185d to calculate the output power of the motor 145, are determined during the automatic calibration process described above. Some of the calculation parameters for a motor 145 are: stator resistance, stator leakage reactance, magnetization reactance, rotor leakage reactance, and rotor resistance. Thus, the microcontroller 185d may include instructions for determining the output power of the motor 145 using the sensed current, the sensed motor speed, and the calculation parameters. The instructions are generally equations known to those skilled in the art. It is necessary to understand that other constructions of the controller 150, 150a, 150b, 150c, 150d, and 150e are possible and that the constructions illustrated herein are not limiting the invention.

Variations and modifications are possible within the scope of the appended claims.