JP2009089543A - Smoothing capacitor arranging structure for inverter apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a smoothing capacitor mounting structure for inverter apparatus, which allows a capacitor of capacity effective for smoothing to be built in without incurring the increase of elements or occurrence of wiring. <P>SOLUTION: A smoothing capacitor 7 is mounted together with a switching power module 13 on a main circuit board 11 and they are built in a casing 15. Hereby, as compared with the inverter apparatus where the smoothing capacitor is attached outside to the casing 15, the wiring length between the switching power module 13 and the smoothing capacitor 7 is shortened, and wiring impedance is made extremely small. As a result, it can reconcile actually the downsizing of the smoothing capacitor 7 and the building in the casing 15 by enabling the smoothing capacitor 7 to be used efficiently. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inverter device that converts a DC input into an AC output by a switching power device, and more particularly to an arrangement structure of a smoothing capacitor for smoothing the inverter input.

In an inverter device that converts a DC input into an AC output by a switching power device, a large current ripple is generated on the inverter input side due to voltage fluctuations accompanying switching of the switching power device. For this reason, in order to reduce the burden on DC power sources such as batteries and to extend the life thereof, conventionally, a large-capacity smoothing capacitor with a large volume is externally attached to the casing of the inverter device to smooth the inverter input. (For example, Patent Document 1).
Japanese Patent Laid-Open No. 2000-152626

  When the external smoothing capacitor and the switching power device in the housing are connected to the housing by wiring, the wiring is routed by connecting the inside and outside of the housing. This increases the wiring impedance. In particular, when the switching power device switches at a high speed, the wiring inductance increases in proportion to the switching frequency, so that the wiring impedance becomes considerably high, which causes a further increase in the wiring impedance.

  As described above, when the wiring impedance of the smoothing capacitor is high, it is difficult to take in and out charges to the smoothing capacitor, the smoothing efficiency is lowered, and the inverter input cannot be sufficiently smoothed. Then, as described above, the burden on the DC power supply is increased, which not only adversely affects the life of the DC power supply, but also has an adverse effect that a large current ripple occurs in the inverter output and the loss in the load increases.

  Further, as the current ripple at the inverter output increases, the level of surge voltage accompanying switching of the switching power device also increases, which may cause damage to the switching power device.

  In some cases, a snubber circuit having a capacitor is provided in the casing of the inverter device for suppressing the surge voltage. However, the capacitor of the snubber circuit is insufficient in capacity for smoothing the inverter input, and an external smoothing capacitor cannot be made useless.

  It is also conceivable to reduce the capacity (volume) of the external smoothing capacitor by using it together with the snubber circuit. However, in reality, the capacitor of the snubber circuit that is closer to the switching power device than the smoothing capacitor on the circuit is the result of trying to participate in the smoothing of the inverter input more dominantly than the smoothing capacitor, despite the lack of capacity. The smoothing efficiency of the inverter input by the smoothing capacitor is lowered. For this reason, even if it is used in combination with a snubber circuit, the capacity (volume) of the smoothing capacitor cannot be reduced as expected.

  Therefore, when a snubber circuit composed of resistors, reactances (coils, capacitors), diodes, etc. is used, smoothing of the inverter input does not become space-saving and efficient, it simply increases the number of parts. It may end just to bring Rather, the snubber circuit capacitor may cause an abnormal heat generation of the snubber circuit by participating in the smoothing of the inverter input despite the insufficient capacity. Finding a smoothing function is not an ideal idea.

  In view of the above circumstances, the present invention has been made paying attention to the fact that the inverter device is expected to be used in an environment different from the electrical environment (conditions) that has been conventionally used, An object of the present invention is to provide a smoothing capacitor arrangement structure of an inverter device that can achieve both smoothing of inverter input with high efficiency and miniaturization of the device.

  In order to achieve the above object, the smoothing capacitor arrangement structure of the inverter device according to the present invention described in claim 1 is for smoothing an inverter input in an inverter device that converts a DC input into an AC output by a switching power device. A smoothing capacitor arrangement structure is characterized in that the smoothing capacitor is housed in a moisture-proof or heat radiating housing in which the switching power device is housed.

  According to the smoothing capacitor arrangement structure of the inverter device of the present invention described in claim 1, the smoothing capacitor is disposed in the same casing as the switching power device to which the wiring is connected. For this reason, the wiring distance between the smoothing capacitor and the switching power device is shorter than when the smoothing capacitor is externally attached to the casing of the inverter device as in the conventional case.

  Therefore, the wiring impedance relating to the smoothing capacitor is reduced, and even if the switching power device performs switching at a high speed, the charging / discharging of the smoothing capacitor is not hindered, and the smoothing capacitor can be used efficiently. Therefore, the inverter input can be sufficiently smoothed even if the capacitance (volume) is made smaller than that of the smoothing capacitor externally attached to the conventional casing.

  As a result, it is possible to reduce the size of the inverter device by smoothing the inverter input with high efficiency and realizing the built-in housing by reducing the capacity (volume) of the smoothing capacitor.

  The smoothing capacitor arrangement structure of the inverter device of the present invention described in claim 2 is a smoothing capacitor arrangement structure for smoothing the inverter input in the inverter device that converts the DC input into the AC output by the switching power device. The smoothing capacitor is mounted on a substrate on which the switching power device is mounted.

  According to the smoothing capacitor arrangement structure of the inverter device of the present invention described in claim 2, the smoothing capacitor is mounted on the same substrate as the switching power device to which the wiring is connected. For this reason, the wiring distance between the smoothing capacitor and the switching power device is shorter than when the smoothing capacitor is externally attached to the casing of the inverter device as in the conventional case.

  Therefore, the wiring impedance relating to the smoothing capacitor is reduced, and even if the switching power device performs switching at a high speed, the charging / discharging of the smoothing capacitor is not hindered, and the smoothing capacitor can be used efficiently. Therefore, the inverter input can be sufficiently smoothed even if the capacitance (volume) is made smaller than that of the smoothing capacitor externally attached to the conventional casing.

  As a result, it is possible to reduce the size of the inverter device by smoothing the inverter input with high efficiency and realizing the built-in housing by reducing the capacity (volume) of the smoothing capacitor.

The smoothing capacitor arrangement structure of the inverter device of the present invention described in claim 3 is a smoothing capacitor arrangement structure for smoothing the inverter input in the inverter device that converts the DC input into the AC output by the switching power device. , The length L of the wiring that electrically connects the switching power device and the smoothing capacitor is:
L <50cm
Is,
It is characterized by that.

  According to the smoothing capacitor arrangement structure of the inverter device of the present invention described in claim 3, the length L of the wiring for electrically connecting the switching power device and the smoothing capacitor is within 50 cm. Therefore, it is necessary to mount the device in the same housing as the switching power device, or mount it on the same substrate as the switching power device or another substrate arranged in close proximity. For this reason, the wiring distance between the smoothing capacitor and the switching power device is shorter than when the smoothing capacitor is externally attached to the casing of the inverter device as in the conventional case.

  Therefore, the wiring impedance relating to the smoothing capacitor is reduced, and even if the switching power device performs switching at a high speed, the charging / discharging of the smoothing capacitor is not hindered, and the smoothing capacitor can be used efficiently. Therefore, the inverter input can be sufficiently smoothed even if the capacitance (volume) is made smaller than that of the smoothing capacitor externally attached to the conventional casing.

  As a result, it is possible to reduce the size of the inverter device by smoothing the inverter input with high efficiency and realizing the built-in housing by reducing the capacity (volume) of the smoothing capacitor.

  The smoothing capacitor arrangement structure of the inverter device of the present invention described in claim 4 is a low-voltage, high-current specification in which the inverter device has the DC input of 100 volts or less and the AC output has a peak value of 30 amperes or more. It is characterized by that.

  According to the smoothing capacitor arrangement structure of the inverter device of the present invention described in claim 4, since the DC input of the inverter device is a low voltage of 100 volts or less, the voltage fluctuation of the inverter input is smaller than that in the case of the high voltage. Volume. Therefore, the smoothing capacitor of the inverter device of the present invention is not required to have the capacity (volume) as that of the conventional smoothing capacitor externally attached to the casing of the inverter device.

  For this reason, the smoothing capacitor is built in the same housing as the switching power device, the smoothing capacitor is mounted on the same substrate as the switching power device, and the length L of the wiring for electrical connection to the switching power device is in the range of 50 cm. It can be realized without hindrance.

  Nevertheless, when the AC output of the inverter device becomes a large current of 30 amperes or more at the peak value, the current ripple of the inverter output due to the voltage fluctuation of the inverter input becomes larger than that in the case of the low current. Therefore, the smoothing of the inverter input greatly contributes to the reduction of the loss and heat generation in the load, and also greatly contributes to the suppression of the surge voltage level accompanying the switching of the switching power device.

  As a result, smoothing of the inverter input with high efficiency and downsizing of the inverter device by realizing a built-in housing by reducing the capacity (volume) of the smoothing capacitor can be realized in a more remarkable form.

  According to the smoothing capacitor arrangement structure of the inverter device according to the present invention, the inverter device can be miniaturized by realizing the built-in housing by reducing the capacity (volume) of the smoothing capacitor while smoothing the inverter input with high efficiency. Can do.

  Hereinafter, an inverter device according to an embodiment of the present invention to which the smoothing capacitor arrangement structure according to the present invention is applied will be described.

  First, an inverter device according to the present embodiment will be described with reference to an equivalent circuit diagram shown in FIG. The inverter device of the present embodiment supplies an AC output obtained by converting a DC input from a DC power supply 8 into a three-phase AC to a load 9 such as a motor. The inverter 1 for each phase of U, V, W 3 and 5.

  The inverters 1, 3 and 5 for each phase use insulated gate bipolar transistors (hereinafter abbreviated as "IGBT") as switching power devices. In place of the IGBT, a MOSFET (metal oxide field effect transistor = unipolar transistor), a bipolar transistor, or the like can be used as a switching power device.

  Specifically, the inverter 1 has two IGBTs 1a and 1b of a high side and a low side connected in series, and the other inverters 3 and 5 also have a high side and a low side connected in series, respectively. It has two IGBTs 3a, 3b, 5a, 5b. These three inverters 1, 3, and 5 are connected in parallel, and further, the smoothing capacitor 7 is connected in parallel to constitute the inverter device of the present embodiment. As the smoothing capacitor 7, a film capacitor, an electrolytic capacitor, a ceramic capacitor, or the like can be used.

  Note that flywheel diodes 1c, 1d, 3c, 3d, 5c, and 5d are provided between the collectors and emitters of the IGBTs 1a, 1b, 3a, 3b, 5a, and 5b, respectively.

  Further, the inductance L and the resistance R on the path connecting the DC power supply 8 and the high side of each of the inverters 1, 3, and 5 in FIG. 1 represent equivalent reactance components on this path. .

  Furthermore, the inverter device of the present embodiment is used in a low voltage and large current environment where the DC input from the DC power supply 8 is 100 volts or less and the AC output to the load 9 is 30 amps (peak value) or more.

  Next, the structure of the inverter device of the present embodiment having the above-described circuit configuration will be described with reference to the explanatory diagram of FIG.

  Reference numeral 13 in FIG. 2 is a switching power module in which the IGBTs 1a, 1b, 3a, 3b, 5a and 5b of the inverters 1, 3 and 5 described with reference to FIG. Implemented above. The main circuit board 11 corresponds to a “board on which a switching power device is mounted” in the claims. A smoothing capacitor 7 is mounted on the main circuit board 11 adjacent to the switching power module 13.

  As described above, the main circuit board 11 on which the switching power module 13 and the smoothing capacitor 7 are mounted adjacently is accommodated in the housing 15. The housing 15 is made of a material such as aluminum, copper, or stainless steel having excellent thermal conductivity so that heat generated by the switching power module 13 or the smoothing capacitor 7 can be easily released to the outside. Further, in order to prevent moisture from the main circuit board 11, the switching power module 13, and the smoothing capacitor 7, the surface of the housing 15 may be coated with rubber gel or the inside of the housing 15 may be filled with rubber gel or the like. is there.

  In the inverter device of the present embodiment housed in the casing 15 with such a configuration, the smoothing capacitor 7 and the switching power module 13 are electrically connected by a wiring pattern (not shown) on the main circuit board 11. . Therefore, the wiring distance between the smoothing capacitor 7 and the switching power module 13 is larger than that of a conventional inverter device in which a smoothing capacitor is externally attached to the outside of the housing and electrically connected to the switching power module inside the housing. Becomes much shorter.

  That is, for example, as shown in FIG. 6 and FIG. When the smoothing capacitor 7A is disposed externally, it is necessary to electrically connect the switching power module (not shown) and the smoothing capacitor 7A across the inside and outside of the housing 15 by the wiring 17.

  Further, as shown in the explanatory diagram of FIG. 8, a snubber circuit 19 composed of a resistor, a reactance (coil, capacitor), a diode, etc. (all not shown) is provided on the main circuit board 11 together with the switching power module 13. In the case of mounting, the capacity (volume) of the external smoothing capacitor 7A is slightly reduced by the amount of the capacitor (not shown) in the snubber circuit 19. However, it is still necessary to electrically connect the switching power module and the smoothing capacitor 7 </ b> A through the wiring 17 across the inside and outside of the housing 15.

  When the inverter device of FIGS. 6 to 8 that externally attaches the smoothing capacitor 7A to the housing 15 and the inverter device of the present embodiment shown in FIG. 2 are compared, the wiring distance between the smoothing capacitor and the switching power module can be reduced. The difference is obvious.

  6 to 8, in order to externally attach the smoothing capacitor 7A to the housing 15, the smoothing capacitor 7A and the switching power module are compared with the inverter device of the present embodiment shown in FIG. An equivalent circuit of the inverter device in which the wiring distance is remarkably increased is as shown in the circuit diagram of FIG.

  6 to 9, the same reference numerals as those used in FIGS. 1 and 2 are attached to the same elements and parts as those shown in FIGS. Omitted.

  That is, in the inverter devices of FIGS. 6 to 8, the DC power supply 8 and each of the inverters 1 and 3 are on the path of the connection point of the wiring 17 due to the long wiring distance between the smoothing capacitor 7A and the switching power module. , 5 reactance components (inductance L1 and resistance R1) different from reactance components (inductance L and resistance R) on the path connecting the high-side sides are generated in a non-negligible magnitude.

  Thereby, in the inverter device with the smoothing capacitor 7A externally attached to the housing 15 as shown in FIGS. 6 to 8, the wiring impedance in the wiring portion between the smoothing capacitor 7A and the switching power module is the same as that of the inverter device of this embodiment. It becomes much larger than that. For this reason, the taking in and out of the electric charge to and from the smoothing capacitor 7A is greatly inhibited.

  In particular, when the IGBTs 1a, 1b, 3a, 3b, 5a, and 5b of the inverters 1, 3, and 5 shown in FIG. 9 perform switching at high speed, the inductance component in the reactance component of the wiring 17 depends on the switching frequency. Become very expensive. For this reason, the degree to which the impedance of the wiring 17 becomes very high and the charging / discharging of the charge to / from the smoothing capacitor 7A is hindered becomes more remarkable.

  Therefore, in the inverter device in which the smoothing capacitor 7A is externally attached to the housing 15 as shown in FIGS. 6 to 8, the capacity of the smoothing capacitor 7A cannot be fully utilized, and the capacity (volume) of the smoothing capacitor 7A is increased accordingly. The vicious circle that must be done arises, and the increase in size of the inverter device cannot be avoided.

  Further, when the smoothing capacitor 7A cannot play a sufficient role for smoothing, an inverter having a large current ripple as shown in the graph of FIG. 10 that appears due to voltage fluctuations accompanying switching of the IGBTs 1a, 1b, 3a, 3b, 5a, and 5b. The DC power supply 8 has to supply almost all inputs. As a result, the ripple width of the current flowing through the DC power supply 8 is increased, the burden on the DC power supply 8 is increased, and the life is shortened.

  Moreover, when the current ripple at the inverter input increases, as shown in the graph of FIG. 11, a large current ripple is also generated at the inverter output, and the loss at the load 9 to which the AC output of the inverter device is supplied increases. Arise.

  As the current ripple at the inverter output increases, as shown in the graph of FIG. 12, the level of surge voltage associated with switching of the IGBTs 1a, 1b, 3a, 3b, 5a, 5b increases, so that the IGBTs 1a, 1b, 3a, 3b, 5a, 5b may be a cause of damage. When a MOSFET (unipolar transistor) is used as a switching power device in place of the IGBTs 1a, 1b, 3a, 3b, 5a and 5b of the inverters 1, 3 and 5 shown in FIG. 9, it appears between the drain and source along with the switching. As shown in the graph of FIG. 12, the surge voltage level increases as the current ripple at the inverter output increases.

  On the other hand, if the smoothing capacitor 7 and the switching power module 13 are mounted on the main circuit board 11 and built in the housing 15 as in the inverter device of this embodiment shown in FIG. 7 and the switching power module 13 are remarkably shorter than the wiring 17 of the inverter device of FIGS.

  Therefore, as shown in the equivalent circuit diagram of FIG. 1, the DC power supply 8 and the high side of each of the inverters 1, 3, 5 are connected on the path of the wiring connecting the smoothing capacitor 7 and the switching power module 13. Reactance components, such as reactance components (inductance L and resistance R), on the path to be generated occur at all or almost negligible magnitude. For this reason, the charging / discharging of the smoothing capacitor 7 is not greatly hindered.

  In particular, even if the IGBTs 1a, 1b, 3a, 3b, 5a, 5b of the inverters 1, 3, 5 perform switching at high speed, the impedance of the wiring that electrically connects them to the smoothing capacitor 7 is extremely small. The increase in the inductance component of the wiring is slight. Therefore, the taking in and out of the electric charge with respect to the smoothing capacitor 7 is not hindered.

  Therefore, the capacity of the smoothing capacitor 7 can be fully utilized efficiently, and the capacity (volume) of the smoothing capacitor 7 is made smaller than the smoothing capacitor 7A externally attached to the housing 15 as shown in FIGS. However, the inverter input can be sufficiently smoothed.

  As a result, the smoothing capacitor 7 can be mounted on the main circuit board 11 together with the switching power module 13 and incorporated in the housing 15, and the inverter input can be smoothed to the housing 1 while smoothing the inverter input with high efficiency. A reduction in size of the inverter device can be realized by realizing the built-in.

  Further, when the smoothing capacitor 7 can sufficiently play a role in smoothing, the current ripple of the inverter input that appears due to the voltage fluctuation accompanying the switching of the IGBTs 1a, 1b, 3a, 3b, 5a, 5b is as shown in the graph of FIG. Therefore, the DC power supply 8 only needs to supply a stable DC input with almost no current ripple. Thereby, the ripple width of the current flowing through the DC power supply 8 can be suppressed, the burden on the DC power supply 8 can be reduced, and the life of the DC power supply 8 can be extended.

  In addition, when the current ripple at the inverter input decreases, the current ripple generated at the inverter output also decreases (or disappears) as shown in the graph of FIG. 4, thereby suppressing loss in the load 9 to which the AC output of the inverter is supplied. You can (or eliminate).

  Further, as shown in the graph of FIG. 5, the surge voltage level associated with the switching of the IGBTs 1a, 1b, 3a, 3b, 5a, and 5b is lowered according to the suppression of the current ripple at the inverter output, so that the IGBTs 1a, 1b, 3a, 3b, 5a, 5b is less likely to be damaged by the surge voltage, and the reliability of the IGBTs 1a, 1b, 3a, 3b, 5a, 5b can be improved. When a MOSFET (unipolar transistor) is used as a switching power device instead of the IGBTs 1a, 1b, 3a, 3b, 5a and 5b in FIG. 1, the level of the surge voltage appearing between the drain and source accompanying the switching is shown in FIG. It becomes low as shown in the graph.

  In the present embodiment, the configuration in which the switching power module 13 and the smoothing capacitor 7 are accommodated in the casing 15 together with the main circuit board 11 has been described. However, the present invention is also applied to an inverter device without the casing 15. Is possible.

  Further, in the case where the smoothing capacitor 7 is built in the housing 15, the smoothing capacitor 7 is not mounted on the same main circuit board 11 as the switching power module 13 as in the present embodiment, but is housed in the housing 15. Even when the smoothing capacitor 7 is mounted on this substrate, the present invention is applicable.

  The wiring length L between the smoothing capacitor 7 and the switching power module 13 is assumed to satisfy L <50 cm through the present embodiment and the above-described modifications.

  By setting the wiring length L between the smoothing capacitor 7 and the switching power module 13 as described above, in the case of an inverter device having the housing 15, the smoothing capacitor 7 is practically built in the housing 15. It becomes composition. In the case of an inverter device that does not have the housing 15, the smoothing capacitor 7 is actually mounted on the main circuit board 11 that is the same as the switching power module 13 or another board that is arranged close to the switching power module 13. It becomes.

  As a result, the wiring distance between the smoothing capacitor 7 and the switching power module 13 falls within such a length that the wiring impedance related to the wiring is negligible. Therefore, it is possible to efficiently and fully utilize the capacity of the smoothing capacitor 7 without greatly hindering the charge and withdrawal of the charge to and from the smoothing capacitor 7.

  Therefore, even if the capacity (volume) of the smoothing capacitor 7 is reduced to a size that allows the smoothing capacitor 7 to be incorporated in the housing 15, the smoothing capacitor 7 having a small capacity can sufficiently smooth the inverter input. While smoothing the inverter input with high efficiency, it is possible to reduce the size of the inverter device by realizing the built-in housing 15 by reducing the capacity (volume) of the smoothing capacitor 7.

  Moreover, according to the inverter device of this embodiment and each of the modifications described above, since the DC input from the DC power supply 8 is a low voltage of 100 volts or less, the voltage fluctuation of the inverter input is higher than that in the case of a high voltage. It becomes a small volume. Therefore, the smoothing capacitor 7 is not required to have the capacity (volume) as that of the smoothing capacitor 7 of FIGS.

  For this reason, the size of the smoothing capacitor 7 can be built in the housing 15, the size of the smoothing capacitor 7 can be mounted on the same main circuit board 11 as the switching power module 13, or the smoothing capacitor 7 and the switching power module. The wiring length L with 13 can be kept within a range of 50 cm without any problem.

  Nevertheless, when the AC output to the load 9 of the inverter device becomes a large current of 30 amperes or more at the peak value, the current ripple of the inverter output due to the voltage fluctuation of the inverter input becomes a larger volume than the case of the low current. Therefore, the smoothing of the inverter input greatly contributes to the reduction of loss and heat generation in the load 9, and also suppresses the level of surge voltage associated with the switching of the IGBTs 1a, 1b, 3a, 3b, 5a, 5b. Will also contribute greatly.

  As a result, smoothing of the inverter input with high efficiency and downsizing of the inverter device by realizing incorporation of the smoothing capacitor 7 in the housing 15 by reducing the capacity (volume) can be realized in a more prominent form. it can.

It is an equivalent circuit diagram explaining an inverter device according to an embodiment of the present invention. It is explanatory drawing which shows the structure of the inverter apparatus which concerns on one Embodiment of this invention. FIG. 6 is a current waveform diagram of an inverter input in the inverter device according to the embodiment of the present invention. It is a current waveform figure of the inverter output in the inverter apparatus concerning one embodiment of the present invention. FIG. 2 is a waveform diagram of a surge voltage appearing between a collector and an emitter (drain and source) due to switching of each bipolar (unipolar) transistor of FIG. 1. It is explanatory drawing which shows the structural example of the inverter apparatus which attached the smoothing capacitor to the housing | casing externally. It is explanatory drawing which shows the structural example of the inverter apparatus which attached the smoothing capacitor to the housing | casing externally. It is explanatory drawing which shows the structural example of the inverter apparatus which attached the smoothing capacitor to the housing | casing externally. It is the equivalent circuit schematic of the inverter apparatus which attached the smoothing capacitor to the housing | casing. It is a current waveform diagram of the inverter input in the inverter apparatus which attached the smoothing capacitor to the housing. FIG. 6 is a current waveform diagram of an inverter output in an inverter device in which a smoothing capacitor is externally attached to a housing. FIG. 10 is a waveform diagram of a surge voltage appearing between a collector and an emitter (drain and source) due to switching of each bipolar (unipolar) transistor of FIG. 9.

Explanation of symbols

1, 3, 5 Inverter 1a, 1b, 3a, 3b, 5a, 5b IGBT (switching power device)
7, 7A Smoothing capacitor 8 DC power supply 9 Load 11 Main circuit board 13 Switching power module 15 Case 17 Wiring

Claims (4)

A smoothing capacitor arrangement structure for smoothing an inverter input in an inverter device that converts a DC input into an AC output by a switching power device,
The smoothing capacitor is housed in a moisture-proof or heat radiating housing in which the switching power device is housed.
A smoothing capacitor arrangement structure for an inverter device. A smoothing capacitor arrangement structure for smoothing an inverter input in an inverter device that converts a DC input into an AC output by a switching power device,
The smoothing capacitor is mounted on a substrate on which the switching power device is mounted.
A smoothing capacitor arrangement structure for an inverter device. A smoothing capacitor arrangement structure for smoothing an inverter input in an inverter device that converts a DC input into an AC output by a switching power device,
The length L of the wiring that electrically connects the switching power device and the smoothing capacitor is:
L <50cm
Is,
A smoothing capacitor arrangement structure for an inverter device.   The said inverter apparatus is a thing of the low voltage high current specification which makes the said DC input into 100 volts or less and makes the said AC output into the peak value 30 amperes or more, The claim 1, 2, or 3 characterized by the above-mentioned. Smoothing capacitor arrangement structure of the inverter device.

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