Inverter

BACKGROUND

1. Technical Field

0001The present disclosure relates to an inverter, and more particularly, to an inverter capable of attenuating noise during operation by structurally separating a signal unit from a power unit.

2. Description of the Related Art

0002Typically, a motor drive device is supplied with power from a commercial power source. Then, the motor driving device varies the voltage and frequency of the power and supplies the varied power to the motor, thereby controlling the speed of the motor with high efficiency. A conventional motor configured as above is described below.

0003<figref idref="f0001">FIG. 1</figref> illustrates a conventional inverter and power and signal flows thereof, and <figref idref="f0002">FIG. 2</figref> is a perspective view illustrating the conventional motor drive seen from another side.

0004Referring to <figref idref="f0001">FIGS. 1</figref> and <figref idref="f0002">2</figref>, the conventional inverter includes a heat sink 10 and a plurality of circuit boards 20, 30, 40, 50, which are installed on a base.

0005The heat sink 10 is installed on the base.

0006The circuit boards 20, 30, 40, 50 are disposed on a middle base, which is disposed on the heat sink 10.

0007The circuit boards 20, 30, 40, 50 include a power board 20 disposed on the middle base, a cap board 50 disposed on the power board 20, a control board 30 perpendicularly connected to the power board 20, and an I/O board 40 disposed on control board 30.

0008In <figref idref="f0001">FIG. 1</figref>, the hollow arrow indicates flow of a main power along an input terminal 31, a rectification part 22, a DC link 27, an inverter part 23, and an output terminal 32.

0009The solid arrow indicates a switched-mode power supply (SMPS) secondary power source 25, which supplies power to the control board 30, a gate drive, and a sensing and protection circuit 26. The dotted arrow indicates signals of a controller 24 of the control board 30, the gate drive and the sensing and protection circuit 26.

0010In the case of power flow and signal flow of the conventional inverter described above, interference occurs between the output of the rectification part 22 and the output of inverter part 23 due to intersection of main power therebetween.

0011That is, for the conventional inverter, a power terminal, a power unit such as PIM, and a signal unit are installed on the same board.

0012Accordingly, the signal of the conventional inverter is structurally subjected to interference by the flow of main power as described above.

0013<patcit id="pcit0001" dnum="US2013294040A1"><text>US2013/294040A1</text></patcit> discloses an example background art inverter comprising a main board, and a control board electrically connected to the main board and an I/O board.

0014<patcit id="pcit0002" dnum="US5555519A"><text>US 5 555 519 A</text></patcit> discloses an example background art add-on module for a variable speed drive that includes a casing containing an electronic circuit and a connector to plug into a corresponding connector on the variable speed drive.

0015Referring to <figref idref="f0002">FIG. 2</figref>, the conventional I/O board 40 and the control board 30 are electrically connected to each other through a wire 60 for signals, thereby forming a signal line.

0016The I/O board 40 is connected to the power board 20 through a ground wire 70 formed on the corresponding board, and the ground wire 70 connected to the power board 20 is extended and connected to the heat sink 10.

0017According to the configuration described above, the conventional inverter is structurally weak as it uses wires such as a signal wire capable of functioning as a noise antenna and a ground wire.

0018In addition, in the conventional cases, as the wires are used, fire may be caused by contact between the wires and a component generating heat in the process of assembling a product. Thereby, damage to the product and malfunctioning may occur.

0019Prior art documents related to the present disclosure include Korean Patent Application Publication No. <patcit id="pcit0003" dnum="KR1020070053940"><text>10-2007-0053940</text></patcit> (Publication Date: May 28, 2007). This document discloses a flexible print circuit board preventing circuit interference among the layers.

SUMMARY

0020It is an object of the present disclosure to provide an inverter capable of attenuating noise during operation by structurally separating a signal unit from a power unit.

0021Objects of the present disclosure are not limited to the above-described objects and other objects and advantages can be appreciated by those skilled in the art from the following descriptions. Further, it will be easily appreciated that the objects and advantages of the present disclosure can be practiced by means recited in the appended claims and a combination thereof.

0022An inverter according to the invention is defined in claim 1.

0023A further embodiment is defined in the dependent claim. Embodiments which do not fall within the scope of the claims do not describe part of the present invention.

0024According to an embodiment of the present disclosure, a signal unit and a power unit are structurally separated from each other. Thereby, noise may be efficiently attenuated during operation.

0025Further, multiple boards combined to be electrically connected to each other are grounded to a heat dissipation part serving as a heat sink, using a ground screw and a metal rod rather than using a wire. Thereby, the problems resulting from use of wires in the prior art may be addressed.

BRIEF DESCRIPTION OF DRAWINGS

0026<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> illustrates a conventional inverter and power and signal flows thereof.</li><li><figref idref="f0002">FIG. 2</figref> illustrates the structure of the conventional inverter.</li><li><figref idref="f0003">FIG. 3</figref> is a perspective view illustrating an inverter and power and signal flows according to an embodiment covered by the claimed invention.</li><li><figref idref="f0004">FIG. 4</figref> is a perspective view illustrating arrangement of a main board according to an embodiment covered by the claimed invention.</li><li><figref idref="f0005">FIG. 5</figref> illustrates power flow according to an embodiment covered by the claimed invention.</li><li><figref idref="f0006">FIG. 6</figref> illustrates power flow on an EMC board according to an embodiment not covered by the claimed invention.</li><li><figref idref="f0007">FIG. 7</figref> is a perspective view illustrating installation of a control board according to an embodiment covered by the claimed invention.</li><li><figref idref="f0008">FIG. 8</figref> illustrates flow of a secondary power and a signal on a control board according to an embodiment covered by the claimed invention.</li></ul>

DETAILED DESCRIPTION

0027The above objects, features and advantages will become apparent from the detailed description with reference to the accompanying drawings. Embodiments are described in sufficient detail to enable those skilled in the art in the art to easily practice the technical idea of the present disclosure. Detailed descriptions of well known functions or configurations may be omitted in order not to unnecessarily obscure the present disclosure. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Throughout the drawings, like reference numerals refer to like elements.

0028<figref idref="f0003 f0004 f0005">FIG 3-5</figref> describe an embodiment covered by the claimed invention. <figref idref="f0003">FIG. 3</figref> is a perspective view illustrating an inverter and power and signal flows according to an embodiment of the present disclosure, <figref idref="f0004">FIG. 4</figref> is a perspective view illustrating arrangement of a main board according to an embodiment of the present disclosure, and <figref idref="f0005">FIG. 5</figref> illustrates power flow according to an embodiment of the present disclosure.

0029Hereinafter, the structure of an inverter according to an embodiment of the present disclosure will be described with reference to <figref idref="f0003">FIG. 3</figref>.

0030Referring to <figref idref="f0003">FIG. 3</figref>, the inverter according to an embodiment includes a base 100, a heat dissipation part 120, a main board 200, and a control board 400 An I/O board is not shown.

0031The heat dissipation part 120 is installed on the base 100. The area of the heat dissipation part 120 is smaller than the area of the base 100.

0032A side portion of the heat dissipation part 120 is provided with a heat dissipation fan 110, which is exposed to the outside.

0033The main board 200 is disposed at the upper end of the heat dissipation part 120.

0034Herein, the area of the main board 200 may be larger than the area for installation of the heat dissipation part 120.

0035The embodiment covered by the claimed invention comprises a DC link 260 fitted into the main board 200.

0036A plurality of DC links 260 may protrude downward from the main board 200 and be disposed at the side portion of the heat dissipation part 120.

0037Accordingly, the DC links 260 may not protrude upward from the main board 200.

0038In addition, an EMC board 300 not covered by the claimed invention is installed at an upper portion of the main board 200, and an EMC filter 310 is mounted on the EMC board 300.

0039An input terminal 510 is disposed at one side of the main board 200 and an output terminal 520 is positioned adjacent to the input terminal 510.

0040The main board 200 includes an input power connection part 210 (see <figref idref="f0005">FIG. 5</figref>), a rectification part 220, the DC link 260, the inverter part 270, and the output terminal 520.

0041In this embodiment, the control board 400 is perpendicularly installed so as to be electrically connected and fixed to the side portion of the main board 200.

0042Herein, the lower end portion of the control board 400 is preferably disposed so as to be exposed to a side portion of the heat dissipation part 120. That is, the lower end portion of the control board 400 may be exposed to the side portion of the heat dissipation part 120, thereby readily dissipating heat.

0043Herein, the control board 400 includes a SMPS power input unit 411 (see <figref idref="f0008">FIG. 8</figref>), a controller 420, an SMPS power unit 410, and a signal unit 430.

0044The SMPS power input unit 411 is electrically connected to an SMPS power connection part formed on the main board 200. The SMPS power connection part will be described later.

0045Meanwhile, the main board 200 is grounded to a metal rod 320 connected to the heat dissipation part 120 as the metal rod 320 contacts the main board 200 in a penetrating manner. The heat dissipation part 120 is formed of aluminum.

0046In addition, the control board 400 is provided with a ground connection part 451.

0047A ground screw 450 contacting the heat dissipation part 120 is installed on the ground connection part 451.

0048Additionally, although not shown in the figure, the control board 400 fixes an I/O board disposed on the main board 200 by being electrically connected to the I/O board.

0049The I/O board is provided with a pattern connected to the ground connection part 451.

0050Next, a description will be given of a signal flow system according to independent formation of power flow and signal flow through the inverter of the present disclosure configured as above.

0051Hereinafter, power flow of the inverter according to an embodiment covered by the claimed invention will be described with reference to <figref idref="f0003">FIG. 3</figref>.

0052In <figref idref="f0003">FIG. 3</figref>, the hollow arrow indicates flow of a main power along the input terminal 510, the rectification part 220, the DC link 260, the inverter part 270, and the output terminal 520.

0053In addition, the solid arrow indicates flow of a secondary power of SMP supplied from the SMPS power unit 410 to the controller 420 and the signal unit 430.

0054In addition, a signal flow is formed between the controller 420 and the signal unit 430.

0055As described above, according to an embodiment of the present disclosure, intersection of main power flows does not occur.

0056That is, in this embodiment, in implementing power flow and signal flow, the boards 200, 400 are structurally separated from each other. Thereby, interference between signal flows may be prevented.

0057Referring to <figref idref="f0004">FIGS. 4</figref> and <figref idref="f0005">5</figref>, an input AC power is applied to the rectification part 220 via the input power connection part 210 connected to the input terminal 510.

0058Subsequently, the DC power obtained through the rectification part 220 is transmitted to the DC link 260, and the DC link 260 makes the DC power smooth.

0059After passing through the DC link 260, the DC power is applied to the inverter part 270.

0060Herein, a connector 401 is installed at a side portion of the main board 200.

0061The connector 401 is electrically connected to the control board 400 to transfer a signal.

0062Herein, a PWM signal from the control board 400 is transmitted to the inverter part 270 through the connector 401.

0063In addition, the inverter part 270 may output an AC power to the outside via the output terminal 520.

0064In addition, an SMPS power connection part 240 is installed on the main board 200.

0065<figref idref="f0006">FIG. 6</figref> illustrates power flow on an EMC board according to an embodiment not covered by the claimed invention.

0066Referring to <figref idref="f0006">FIG. 6</figref>, the EMC board 300 is disposed on the main board 200.

0067A ground screw 321 is installed on the EMC board 300.

0068The ground screw 321 is fastened to the metal rod 320, which protrudes upward through the main board 200 described above.

0069Herein, an EMC filter 310 and an input power connection part 210 are installed on the EMC board 300.

0070The EMC filter 310 is not electrically connected to either the input power connection part 210 or the output terminal 520.

0071Power flow on EMC board 300 is formed as follows.

0072An AC power input from the input terminal 510 may be transmitted to the main board 200 via the EMC filter 310 and the input power connection part 210.

0073The reference numeral 511 indicates a ground terminal block. <figref idref="f0007">FIG. 7</figref> is a perspective view illustrating installation of a control board according to an embodiment covered by the claimed invention.

0074Referring to <figref idref="f0007">FIGS. 7</figref> and <figref idref="f0008">8</figref>, the main board 200 of this embodiment covered by the claimed invention includes an SMPS power connection part 250.

0075In addition, the control board 400 includes an SMPS power input unit 411 electrically connected to the SMPS power connection part 250 to input a secondary power, a controller, an SMPS power unit 410, and a signal unit 430.

0076In addition, a sensing and protection circuit unit and a gate drive 440 are installed on the control board 400.

0077The SMPS power unit 410 generates the secondary power. Thereby, the SMPS power unit 410 forms flow of the second power transmitted to the controller 420 and signal unit 430 and forms a signal flow between the controller 420 and signal unit 430.

0078When the power is input from the SMPS power connection part 250 to the SMPS power input unit 411, a secondary power used for control, sensing and protection is generated by the SMPS power unit 410.

0079The generated secondary power is supplied to a DSP (not shown), the signal unit 430, and the gate drive 440 to drive the inverter part 270.

0080Thereby, the control board 400 to drive the inverter part 270 may be structurally separated from the main board 200 serving as a power unit forming power flow.

0081According to the configuration and operation described above, in this embodiment, the signal unit is structurally separated from the power unit. Thereby, noise may be efficiently attenuated during operation.

0082The main board 200 may be grounded as the metal rod 320 connected to the heat dissipation part 120 contacts the main board 200 in the penetrating manner.

0083In addition, a ground connection part (451) is formed on the control board 400.

0084Additionally, a ground screw 450 contacting the heat dissipation part 120 is installed on the ground connection part.

0085Further, another connector 402 may be formed on the control board 400 and be electrically connected to the I/O board disposed on the main board 200, thereby fixing the I/O board.

0086The I/O board may be provided with an inverter connected to the ground connection part.

0087According to the configuration and operation described above, the present disclosure is grounded to the heat dissipation part using a metal rod, a ground screw, and a circuit pattern rather than using a wire. Thereby, the problems of the conventional technology such as damage to a product, malfunctioning and fire, which may occur in the event that the wire contacts a heat dissipating component in the product in the process of assembling the product, may be efficiently addressed.