JP2010154695A - Inverter device and design support method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively lessen radiation noises emitted from a main circuit of an inverter device, reduce the weight of the inverter device, and improve the heat dissipation properties of the inverter device. <P>SOLUTION: The inverter device includes an inverter device circuit which is composed of a power semiconductor element and converts DC power into AC power, a snubber circuit which protects the power semiconductor element from overvoltage occurring upon switching, and a conductive path serving as a conductor connecting the inverter device circuit to the snubber circuit. The inverter device also includes a concealing conductor that forms a plane at a position opposite to a looped plane formed by the conductive path. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a noise reduction technique of an inverter device that converts power by switching of a power semiconductor, and in particular, a shielding conductor for shielding electromagnetic noise radiated during switching operation is effectively arranged in an appropriate size. The present invention relates to an inverter device capable of enhancing the noise reduction effect and a design support method for the device.

  The inverter device performs power conversion by switching of a power semiconductor element such as a transistor or an IGBT, and conductive or radioactive noise is generated along with the switching operation.

FIG. 14 shows an equivalent circuit diagram focusing on the noise of the inverter main circuit part, and a noise current conduction path (conduction path 1), which is one of the radiation noise sources, as will be described in detail later. This current is generated with the switching of the power semiconductor element. That is, when the power semiconductor element is switched, the output potential U varies due to the switching. As a result, the stray capacitance (C _N ) of the power semiconductor element is charged and discharged, and a noise current flows through the conduction path 1 via the stray capacitance (C _N ) and the snubber capacitor (C _S ). The current loop formed by such a conduction path acts as an antenna (loop antenna), and radiation noise is generated therefrom. (See Non-Patent Document 1 for details).

For example, the radiation noise generated as described above is affected by malfunctions of peripheral devices, noises on wireless devices, and the like, and therefore, the following measures 1) to 4) are generally taken.
1) Cover and shield the device with metal.
2) Insert countermeasure parts such as a noise filter.
3) Strengthen the ground.
4) Shield control lines and power lines.

As a conventional technique for reducing radiation noise, for example, in Patent Document 1, a main circuit unit and a control circuit unit for controlling the main circuit unit are individually separated and stored by a shielding housing, thereby storing the main circuit. There has been proposed a power conversion unit capable of suppressing noise generated from the unit and particularly reducing the influence on the control circuit unit.
JP 2006-230064 IEEJ Transactions D, Vol. 118, No. 6, 1998, p. 757-p. 766 “Analysis and Reduction Method of Electromagnetic Noise Radiated from Power Converter”

  However, according to the above-described conventional technique, the generated radiation noise is shielded by covering the main circuit unit and the control circuit unit with the shielding housing, and the radiation noise propagating to the surroundings can be reduced. Since the main circuit unit and the control circuit unit are covered with the casing, there are problems in terms of weight reduction and heat dissipation performance.

  The present invention has been made in view of the above-described circumstances, and it is possible to effectively reduce radiation noise generated from the main circuit unit, and to reduce the weight of the device and improve the heat dissipation performance. An object of the present invention is to provide a device design support method.

  In order to achieve the above object, an inverter apparatus according to the present invention comprises a power semiconductor element, an inverter circuit section for converting DC power into AC power, and a snubber circuit for overvoltage protection during switching of the power semiconductor element. And a conduction path for conducting a conductor connection between the inverter circuit section and the snubber circuit section, a shielding conductor for forming a surface is provided at a position facing the loop surface formed by the conduction path. Features.

  In the present invention, paying attention to the fact that the conductive path connecting the inverter circuit part and the snubber circuit part forms a loop surface, which acts as an antenna to radiate electromagnetic noise, and shields it at a position facing this loop surface. Since the conductor is provided in a planar shape, radiation noise generated from the main circuit portion can be effectively reduced.

  Preferably, the inverter circuit unit is configured on a printed circuit board, and a shielding conductor is formed on the printed circuit board, or provided in a cooling unit for dissipating heat generated from the inverter device, or a casing that covers the inverter device. By adjusting the positional relationship with the inverter circuit unit, the shielding conductor can be easily formed in a planar shape at a position facing the loop surface formed by the conduction path.

  In addition, the distance between the conduction path and the shielding conductor is 10 mm or less, and it is practical that the dimension of the surface facing the loop surface formed by the conduction path of the shielding conductor is equal to or larger than the dimension of the loop surface. It is preferable because it provides a shielding effect at the level.

In addition, the interval device according to the present invention is such that the distance (interval) between the shielding conductor and the conduction path is x, the length of one side of the rectangular surface facing the loop surface formed by the conduction path of the shielding conductor, and the conduction path. The following formula is satisfied, where y is the difference from the length of the corresponding side of the formed rectangular loop surface and y is the unit.
y ≧ 6x-55

  By determining the distance x and the difference y so as to satisfy the above relational expression, a shielding conductor having an appropriate size can be provided in accordance with the situation when the main circuit portion of the inverter device is mounted on the housing.

  A design support method for an inverter device according to the present invention is a method for supporting the design of an inverter device using a computer device, wherein the distance between the shielding conductor and the conduction path is x, and the conduction path of the shielding conductor is formed. Data representing the relationship between the distance x and the difference y for each radiation field reduction effect, where y is the difference between the length of one side of the surface facing the loop surface and the length of one side of the loop surface formed by the conduction path And an effect collection stage that receives the measurement data of the radiation field reduction effect sent from the installation location and stores it for each specific classification such as model, design department, installation location, etc. Including a stage for calculating a correction value related to data representing the relationship and storing the calculation result, a required specification of the radiation field reduction effect of the inverter device to be designed, and a classification relating to the inverter device. Either one of the design conditions and the distance x and the difference y is accepted as input data, data representing the relationship is extracted based on the design conditions and the correction value, and the distance x and the difference y are not input. And calculating an effect collecting step for the inverter device manufactured based on the result of the calculation.

  In the present invention, a feed test is sequentially performed on the inverter device manufactured using the relational expression of the distance x and the difference y obtained in advance for each radiation electric field reduction effect by simulation or the like, and the result is fed back to obtain a correction value as Since it is used for design, it is possible to design according to the actual situation.

  As the correction value, the slope of the relational expression or the numerical value of the intercept may be corrected, but the radiation field reduction effect for extracting the relational expression used as a design is determined from the radiation field reduction effect of the required specification. By using this as a correction value, an inverter device having an effective shielding ability can be designed without requiring a complicated correction calculation.

  According to the present invention, since the shielding conductor for forming the surface is provided at a position opposite to the loop surface formed by the conductive path connecting the inverter circuit portion and the snubber circuit portion, the radiation generated from the main circuit portion is provided. Noise can be effectively reduced.

  Further, instead of providing a shielding housing, providing a shielding conductor as a surface facing a loop surface formed by a conductive path on a printed circuit board, a cooling unit, or a part of the housing reduces the weight of the device. The heat dissipation performance can be improved.

  Furthermore, a relational expression between the size of the shielding conductor and the arrangement position is stored for each noise reduction level, and the shielding unit of the inverter device is designed using this, and the above-mentioned data is used based on the field data of the product. By correcting this relational expression, it is possible to provide a high-quality inverter device having an excellent shielding effect.

  Embodiments of the present invention will be described below. FIG. 1 is a component layout diagram of an inverter device 10 according to a first embodiment of the present invention. As shown in this figure, the main circuit portion 11 of the inverter device 10 is configured on a printed circuit board 12. The inverter main circuit unit 11 includes, as main components, a rectifying circuit unit 16 that rectifies current, an electrolytic capacitor 15 that smoothes a direct current output from the rectifying circuit unit 16, a snubber circuit unit 14 that suppresses overvoltage, and An inverter (INV) circuit unit 13 that converts direct current into alternating current is mounted on the printed circuit board 12. The inverter circuit unit 13 includes a power semiconductor element such as an IGBT, and generates an alternating current by performing a switching operation according to a control signal input from the outside. Hereinafter, although IGBT is demonstrated to an example, the power semiconductor element by this invention is not restricted to this.

FIG. 14 shows an equivalent circuit focusing on the noise of the inverter main circuit unit 11. In this figure, L _{1 to} L ₄ represent wiring inductances. Also, C _N is the stray capacitance between the collector and the emitter of the IGBT, C _C represents the stray capacitance between the ground and the intermediate point U of series connected IGBT of the inverter circuit section 13. The positive power line 17 of the current rectified by the rectifier circuit unit 16 is connected to one end of the electrolytic capacitor 15 and the snubber circuit unit 14 and the positive side of the inverter circuit unit 13, and the negative power line 18 of the rectifier circuit unit 16 is The other end of the electrolytic capacitor 15 and the snubber circuit unit 14 and the negative side of the inverter circuit unit 13 are connected.

  As shown in FIG. 14, a loop formed by the inverter circuit unit 13, the snubber circuit unit 14, and the plus side and minus side power supply lines 17 and 18 is defined as a conduction path 1. The conduction path 1 is formed on a printed board as shown in FIG. When a noise current flows through the conduction path 1 along with the switching of the IGBT in the inverter circuit section, the conduction path 1 acts as an antenna (loop antenna), and radiation noise is generated.

  For this reason, a conductor plate is provided so as to face the loop surface formed by the conduction path 1. This configuration has an extremely excellent radiation noise reduction effect as described below.

<Verification of radiation noise reduction effect according to the present invention>
2 to 6 show results of verifying the radiation noise reduction effect of the present invention by simulation. FIG. 2 simulates the conduction path 1 and the conductor plate, and shows the effect of reducing the radiated electric field intensity by the conductor plate with respect to the generated radiation noise. The larger the negative value of the radiation field reduction effect on the vertical axis in the figure, the greater the reduction effect. For example, in the figure, −20 dB means that there is a radiation field reduction effect of 20 dB. As shown in the graph of FIG. 2 (a), the position where the conductor plate faces the loop surface (FIG. 2 (b)), that is, the conductor plate and the loop surface of the conduction path 1 are substantially parallel and on the loop surface. It can be confirmed that the radiation noise generated from the conduction path 1 is reduced by arranging the conductor plates so that the conductor plates exist. In addition, the effect of reducing radiation noise is higher than when the conductor plate is arranged at a position different from the facing position (FIG. 2C), for example, at a position where the conductor plate is perpendicular to the loop surface of the conduction path 1. I can confirm.
Hereinafter, conditions for having a practically excellent radiation noise reduction effect will be described.

<Conditions regarding distance between conductive path 1 and shielding conductor>
This will be described with reference to the radiation noise analysis result using the simulation shown in FIG. FIG. 3A shows the relationship between the “distance between the conduction path 1 and the conductor” and the radiation electric field reduction effect. This figure is a graph when the “conductor dimension—the dimension of the conduction path 1” (see FIG. 4) described later is 0 mm. The radiation field reduction effect refers to the difference between the radiation field when there is no conductor and the radiation field when there is a conductor. Further, the distance between the conduction path 1 and the conductor means the distance between the conduction path 1 and the conductor shown in FIG.

  From FIG. 3A, it is confirmed that the radiation field reducing effect is larger as the “distance between the conduction path 1 and the conductor” is smaller. In addition, it can be expected that the radiation electric field is reduced to a practical level by setting the distance between the conductive path 1 and the conductor to 10 mm or less where the reduction effect is remarkably increased.

<Conditions regarding dimensions of shielding conductor>
Next, a description will be given with reference to a radiation noise analysis result using the simulation shown in FIG. FIG. 4 (a) shows the relationship between “the size of the conductor—the dimension of the conduction path 1” and the radiation electric field reduction effect when the “distance between the conduction path 1 and the conductor” (see FIG. 3) is 10 mm. . Here, “the dimension of the conductor−the dimension of the conduction path 1” means the difference between the dimension of the conductor plate and the dimension of the conduction path 1 shown in FIG.

  From this figure, it is confirmed that the radiation electric field reduction effect is larger as “the dimension of the conductor—the dimension of the conduction path 1” is larger. In order to take a significant noise countermeasure, it is preferable that “the dimension of the conductor−the dimension of the conduction path 1” is 0 or more, that is, the dimension of the conductor is limited to the dimension of the conduction path 1 or more.

<Conditions regarding the relationship between "distance between conduction path 1 and conductor" and "dimension of conductor-dimension of conduction path 1">
FIG. 5 is a graph showing the relationship between “the size of the conductor—the size of the conduction path 1” and the radiation electric field reduction effect for each “distance between the conduction path 1 and the conductor”.

  In this figure, the distance between the conduction path 1 and the conductor means the distance between the conduction path 1 and the conductor shown in FIG. Further, “the dimension of the conductor—the dimension of the conduction path 1” means the difference between the dimension of the conductor plate and the dimension of the conduction path 1 shown in FIG.

  From FIG. 5, it can be seen that the larger the “conductor size—the size of the conduction path 1” is, the greater the effect of reducing the radiation electric field is. Further, it can be seen that, even if “the size of the conductor—the size of the conduction path 1” is the same, the smaller the “distance between the conduction path 1 and the conductor” is, the higher the radiation electric field reduction effect is. Therefore, it can be said that the effect of reducing the radiated electric field by the conductor plate is determined by the influence of both “the dimension of the conductor—the dimension of the conduction path 1” and “the distance between the conduction path 1 and the conductor”.

  Therefore, FIG. 6 shows the relationship between “the size of the conductor—the size of the conduction path 1” and “the distance between the conduction path 1 and the conductor” that provides a certain radiation field reduction effect (5 dB, 10 dB, 15 dB, 20 dB, 25 dB) The relationship between “the dimension of the conductor—the dimension of the conduction path 1” and “the distance between the conduction path 1 and the conductor” is clarified.

  From FIG. 6, it can be seen that there is a correlation between “the size of the conductor—the size of the conduction path 1” and “the distance between the conduction path 1 and the conductor”, which can obtain a certain radiation field reduction effect. Therefore, it is possible to approximate the relationship between “the size of the conductor—the size of the conduction path 1” and the “distance between the conduction path 1 and the conductor”, which can provide a certain radiation field reduction effect. For example, the relationship between “the size of the conductor—the size of the conduction path 1” and the “distance between the conduction path 1 and the conductor”, where the radiation field reduction effect is 5 dB, can be approximated by Equation 1. Then, it can be confirmed from FIG. 6 that the approximation can be performed with the formula 1 with high accuracy.

y ≧ 6x−55 [mm] (Formula 1)
Where x: distance between the conductive path 1 and the conductor [mm]
y: Dimension of conductor-dimension of conduction path 1 [mm]

In order to obtain a radiation field reduction effect of 5 dB or more, which is considered to be an effective noise countermeasure, the size of the conductor and the position of the conductor with respect to the conduction path 1 may be determined based on Equation 1.
When a higher radiation noise reduction effect is required depending on the installation environment or the like, an approximate straight line equation calculated by a method such as a least square method based on the points corresponding to the required specifications from FIG. 6 is used.
Next, an example of how to form the conductor surface will be described.

  When the inverter circuit unit 13 is configured on a printed circuit board, a conductor surface is formed on the printed circuit board 12. For example, in a double-sided or multilayer substrate, a layer different from the layer in which the conduction path 1 is wired may be a copper solid surface. In particular, by forming a circuit on the other printed circuit board portion with the wiring back surface of the conduction path 1 being a solid surface, it is possible to reduce the size and weight by improving the circuit mounting density while obtaining the noise reduction effect.

  When the inverter device 10 has a cooling part such as a cooling fin, a conductor surface is formed on the cooling part. The conductor surface may be formed on at least a part of the cooling part. For example, if the cooling part is composed of a base part and a fin part, the conductor surface may be formed on the base part.

  When a housing that covers at least a part of the inverter device 10 is provided, a conductor surface is formed on the housing portion. The cooling part and the conductor surface may be made of the same material or different materials. For example, the surface facing the loop surface formed by the conduction path 1 may be a conductor, and the other surface may be plastic. Moreover, there is no restriction on the structure of the housing. For example, there may be an opening.

  As described above, according to the present embodiment, the conductive plate is provided at a position facing the loop surface formed by the conduction path, thereby causing the conduction path 1 due to the magnetic flux generated by the switching operation of the inverter circuit unit 13. Radiation noise can be effectively reduced. In particular, it is possible to reduce the weight and improve the heat dissipation performance as compared to the case where the entire device or circuit is covered with a conductor to shield radiation noise.

  Next, a second embodiment of the present invention will be described. In the present embodiment, a method for supporting the design of an inverter device in which shielding conductors are effectively arranged using the technique of the first embodiment will be described.

  FIG. 7 is a functional block diagram of a computer device used in this design support method. In this figure, a computer device 50 is connected to a terminal device 41 in a design department and a portable terminal 42 owned by a local worker via a communication network 40 such as an in-house LAN or an external Internet.

  The computer device 50 receives, via the communication network 40, a transmission / reception unit 51 for communicating with other devices, a storage unit 53 for storing various data, an arithmetic processing unit 52 for executing arithmetic processing, and data input An input unit 54 is provided.

  In addition, the arithmetic processing unit 52 registers basic data for designing in the design basic information DB 71 such as transmission / reception processing means 60 for performing transmission / reception processing with the transmission / reception unit 51 and relational data for each radiation field reduction effect. Design basic information registration means 61 for performing design conditions input means 62 for inputting design conditions such as required specifications related to the radiation electric field reduction effect, and a design value is calculated by executing a predetermined calculation based on the basic design information and design conditions. Design value calculation means 63, calculation result transmission means 64 for transmitting the calculated design value to the terminal device 41, field test data input means 65 for inputting field test data relating to the radiation field reduction effect of the product, and field test data And correction value calculation means 66 for calculating a correction value for executing a predetermined calculation. Each means 60-66 is realizable by a program as a function of CPU.

(Design basic information registration stage)
First, basic information used for design is input via the input unit 54 provided on the terminal device 41 or the computer device side. The input basic information is stored in the design basic information DB 71. As shown in FIG. 8, the design basic information DB 71 is composed of a relational expression table 71a (FIG. 8A) and a correction value table 71b (FIG. 8B). The relational expression table 71a shown in FIG. 8A stores parameters of the relational expression of the distance x and the difference y calculated by simulation for each radiation field reduction effect. When the relational expression is represented by a straight line, numerical values of the slope (a) and the intercept (b) are stored as parameters. The relational expression is not limited to a straight line and may be a quadratic expression or other expressions.

  In the correction value table 71b shown in FIG. 8B, correction values are stored for each identification information indicating the model, design department, and installation location. By default, 0 is set.

(Design conditions etc. input stage)
The design person in charge of the department inputs the required specification value of the radiation field reduction effect of the inverter device to be designed and the design conditions such as the identification information of the model of the inverter device, the design department, and the installation location via the terminal device 41. .

  Further, the person in charge of the design assumes any one of the distance x and the difference y, and similarly inputs from the terminal device 41.

  The input information is stored in the design condition table 72 by the design condition input means 62. FIG. 10 is a data configuration example of the design condition table 72. In addition to information indicating the classification of the model, design department, and installation location, the required specification value of the radiation electric field reduction effect and the design values of the distance x and the difference y can be stored. In the design condition input stage, as the design value, one of the numerical values input by the designer in charge of the distance x and the difference y is stored.

(Design value calculation stage)
Hereinafter, the operation of the design value calculation means 63 will be described with reference to FIG.
When the design value calculation means 63 is activated, it first extracts the required specification value of the radiation electric field reduction effect from the design condition table 72 (S101), and also extracts the correction value corresponding to the classification from the correction value table 71b (S101). S102). Then, the correction value extracted in step S102 is added to the required specification value extracted in step S101 (S103), the corrected radiation electric field reduction effect is calculated, and after correction with reference to the relational table 71a The values of parameters a and b in the relational expression corresponding to the radiation electric field reduction effect are extracted (S104).

  Next, it is determined whether or not the distance x is set in the design condition table 72. If the distance x is set, the above expression having the values of the parameters a and b of the relational expression extracted in step S104. Substituting into 1 and calculating the difference y (S106), the calculation result is stored in the column of difference y in the design condition table 72 (S109).

  On the other hand, if “NO” in the step S105, it is determined whether or not the difference y is set in the design condition table 72. If it is set, the difference y is extracted from the parameter of the relational expression extracted in the step S104. The distance x is calculated by substituting it into the above equation 1 having the values of a and b (S108), and the calculation result is stored in the column of distance x in the design condition table (S109).

  If “NO” in the step S107, an error message is output on the terminal device 41, and it is prompted to enter a numerical value of either the distance x or the difference y (S110).

  The calculation result transmitting means 64 transmits the calculation result stored in step S109 to the terminal device 41.

(Effect collection stage)
When the inverter device manufactured based on the calculation result is installed on the site, the local worker measures the effect of reducing the radiated electric field, and inputs the measured value together with the product ID to the portable terminal 42. The input data is sent to the computer device 50 and stored in the measured value column of the product ID in the field test DB 73 by the field test data input means 65.

  FIG. 12 is a data configuration example of the field test DB 73. Here, the product ID, classification, required specification, and design value are copied from the design condition table 72 in advance. When the actual design value is changed, the changed value is set from the terminal device 41, and the design value column of the field test DB 73 is updated.

(Correction value calculation stage)
Next, the operation of the correction value calculation means 66 will be described with reference to FIG. When the correction value calculation means 66 is activated upon completion of the operation of the field test data input means 65, the correction value calculation means 66 accesses the field test DB 73 and uses the distance x and difference y values in the product design value column as coordinate points. In this graph, the straight line closest to the coordinate point is specified (S201). Next, the radiation field reduction effect of the straight line is extracted (S202), and the difference from the measured value of the field test data is calculated (S203). Then, the correction value associated with the classification of the product in the correction value table 71b is corrected based on the calculation result of step S203 (S204). As a method of correcting the correction value, for example, if the field data measurement for the classification is the first time, the calculation result is set as it is, and if it is the second time or later, the correction value is set so as to be close to the measurement value by a predetermined ratio of the calculation result. There is a method of correcting.

  The correction value corrected by the above procedure is used when calculating the distance x or the difference y for the design target products of the same classification in the above-described design value calculation stage.

  As described above, according to the present embodiment, the relational expression between the size (difference y) of the shielding conductor and the arrangement position (distance x) is stored for each noise reduction level, and this is used to shield the inverter device. By designing the part and correcting the relational expression based on the field data of the product, it is possible to provide a high-quality inverter device having an excellent shielding effect. In particular, the shielding effect may differ depending on the model and how the device is grounded in the field, etc.So, by measuring the effect at each installation location and reflecting it in the correction value, the relational expression obtained by simulation etc. It can be used in a highly effective manner according to the actual situation.

  The present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the scope of the invention. For example, in the above embodiment, the correction value for obtaining the radiation electric field reduction effect when extracting the relational expression is calculated from the required radiation electric field reduction effect, but this is required for each classification such as the installation location. A correction value for changing a parameter (gradient or the like) of the relational expression of the radiation field reducing effect may be obtained.

1 is a component layout diagram of an inverter device 10 according to a first embodiment of the present invention. It is explanatory drawing of the influence on the radiation electric field reduction effect by the positional relationship of the conduction path 1 and a conductor board, and Fig.2 (a) is explanatory drawing of the difference of the radiation electric field reduction effect in arrangement | positioning of this invention, and arrangement | positioning different from this invention. FIG. 2B is an explanatory diagram of an example of the positional relationship between the conductor plate and the transmission path 1 according to the present invention, and FIG. 2C is an explanatory diagram of an arrangement example different from the present invention. It is explanatory drawing of the relationship between the "distance between the conduction path 1 and a conductor" and a radiation electric field reduction effect, Fig.3 (a) shows the relationship between the "distance between the conduction path 1 and a conductor" and a radiation electric field reduction effect by simulation. FIG. 3B is a graph for explaining the distance between the conduction path 1 and the conductor. FIG. 4A is an explanatory diagram of a radiation noise analysis result using simulation, and FIG. 4A shows “a conductor dimension—a dimension of the conduction path 1” and a radiation electric field when the “distance between the conduction path 1 and the conductor” is 10 mm. FIG. 4B is a graph showing the relationship of the reduction effect, and is an explanatory diagram of the difference between the size of the conductor plate and the size of the conduction path 1. It is the graph which showed the relationship between "the dimension of a conductor-the dimension of the conduction path 1", and the radiation electric field reduction effect for every "distance between the conduction path 1 and a conductor." It is explanatory drawing of the approximate straight line for every radiation electric field reduction effect when setting "the dimension of a conductor-the dimension of the conduction path 1" as a y-axis, and setting the "distance between the conduction path 1 and a conductor" as an x-axis. It is a functional block diagram of the computer apparatus used for the design support method by the 2nd Embodiment of this invention. FIG. 8A is a data structure diagram of the design basic information DB 71 of FIG. 7, and FIG. 8A shows the data structure of the relational expression table and FIG. 8B of the correction value table. It is explanatory drawing of the approximate linear formula for every radiation electric field reduction effect which determines the parameter set to the relational expression table of Fig.8 (a). It is a data structure figure of the design condition table 72 of FIG. It is a flowchart which shows the process sequence of the design value calculating means 63 of FIG. It is a data structure figure of field test DB73 of FIG. It is a flowchart which shows the process sequence of the correction value calculating means 66 of FIG. It is an equivalent circuit diagram focusing on the noise of the inverter main circuit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission path 2 Conductor board 10 Inverter device 11 Main circuit part 12 Printed circuit board 13 Inverter circuit part 14 Snubber circuit part 15 Electrolytic capacitor 16 Rectifier circuit part 17 Positive side power line 18 Negative side power line 40 Communication network 41 Arranged in each design department Terminal device 42 mobile terminal 50 computer device 51 transmission / reception unit 52 arithmetic processing unit 53 storage unit 54 input unit 60 transmission / reception processing unit 61 design basic information registration unit 62 design condition input unit 63 design value calculation unit 64 calculation result transmission unit 65 field Test data input means 66 Correction value calculation means 71 Design basic information DB
71a Relational expression table 71b Correction value table 72 Design condition table 73 Field test DB

Claims (8)

An inverter circuit unit configured by a power semiconductor element and converting power from DC to AC;
A snubber circuit section for overvoltage protection during switching of the power semiconductor element;
A conduction path for conducting a conductor connection between the inverter circuit portion and the snubber circuit portion;
In an inverter device having
An inverter device comprising a shielding conductor for forming a surface at a position opposite to a loop surface formed by the conduction path.   2. The inverter device according to claim 1, wherein the inverter circuit portion is provided on a printed board, and the shielding conductor is formed in a planar shape on the printed board.   The inverter device according to claim 1, further comprising a cooling unit for radiating heat generated from the inverter device, wherein the shielding conductor is formed in a planar shape in the cooling unit.   The inverter device according to claim 1, further comprising a housing that covers at least a part of the inverter device, wherein the shielding conductor is formed in a planar shape on the housing.   5. The inverter device according to claim 1, wherein a distance between the conduction path and the shielding conductor is 10 mm or less.   6. The inverter device according to claim 1, wherein a dimension of a surface of the shielding conductor facing the loop surface formed by the conduction path is equal to or larger than a dimension of the loop surface. The distance between the shielding conductor and the conduction path is x, the length of one side of the shielding conductor facing the loop surface formed by the conduction path, and the length of one side of the loop surface formed by the conduction path The inverter apparatus according to claim 1, wherein the following equation is satisfied, where y is a difference between the two and a unit is millimeter.
y ≧ 6x-55 A method for supporting the design of an inverter device using a computer device,
The distance between the shielding conductor and the conduction path is x, the length of one side of the shielding conductor facing the loop surface formed by the conduction path, and the length of one side of the loop surface formed by the conduction path Storing the data representing the relationship between the distance x and the difference y for each radiation field reduction effect, where y is the difference between
An effect collection stage that receives measurement data of the radiation field reduction effect sent from the installation location and stores it for each specific classification such as model, design department, installation location, etc.
Calculating a correction value for data representing the relationship based on the measurement data, and storing the calculation result;
One of the required specification of the radiation field reduction effect of the inverter device to be designed, the design condition including the classification relating to the inverter device, and the distance x and the difference y is received as input data, and the design condition and the Extracting data representing the relationship based on a correction value, calculating the other one of the distance x and the difference y that has not been input, and outputting a result of the calculation,
A method for supporting design of an inverter device, wherein the effect collecting step is executed for an inverter device manufactured based on a result of the calculation.