WO2019181774A1

WO2019181774A1 - Resistance device and inverter device

Info

Publication number: WO2019181774A1
Application number: PCT/JP2019/010790
Authority: WO
Inventors: 圭司原田; 正則景山; 中島　浩二; 雄二白形; 善一野月; 隆史内藤; 章吉村; 善紀有賀
Original assignee: 三菱電機株式会社; Koa株式会社
Priority date: 2018-03-19
Filing date: 2019-03-15
Publication date: 2019-09-26
Also published as: JP6984002B2; CN111837204A; JPWO2019181774A1; TWI695397B; TW201939546A

Abstract

The purpose of the present invention is to provide a resistance device which is compact and does not cause the lifespan of a capacitor to deteriorate. The resistance device according to the present invention comprises: at least one resistor (61) connected in series to a smoothing capacitor (5a) and a smoothing capacitor (5b), which are connected in series to each other; a resistor (62a) connected in parallel to the smoothing capacitor (5a); a resistor (62b) connected in parallel to the smoothing capacitor (5b); and an insulating case (50) enclosing the resistors (61, 62a, 62b) by means of a sealant (56) which fills inner cavity.

Description

Resistance device and inverter device

This invention relates to a resistance device.

The conventional resistance device includes an inrush current prevention resistor and a voltage balance resistor. These two types of resistors are fixed to a printed wiring board or a casing, respectively.

The inrush current prevention resistor is used to suppress the inrush current to the capacitor that flows when the input power is turned on. A relay is connected in parallel to the inrush current prevention resistor, and the current flowing through the inrush current prevention resistor is bypassed by switching the relay from OFF to ON after charging the capacitor.

When a plurality of capacitors are connected in series in order to compensate for the insufficient withstand voltage of the capacitor, the voltage applied to each capacitor can be unbalanced depending on the variation in leakage current of each capacitor. In order to prevent this, a voltage balance resistor is connected in parallel to each capacitor.

Patent Document 1 discloses a resistance device having a normal discharge resistor and a rapid discharge resistor having a resistance value smaller than that of the normal discharge resistor. Normally, the discharging resistor is used as an inrush current preventing resistor, and the rapid discharging resistor is used as a voltage balance resistor.

JP 2014-36145 A

In order to suppress the inrush current of the capacitor, the inrush current prevention resistor is required to have pulse resistance. The larger the capacitance of the capacitor, the larger the size of the inrush current prevention resistor. Therefore, although the inrush current prevention resistor is used only when the input power is turned on, there is a problem that a resistor having a large size is required.

On the other hand, the voltage balance resistor generates heat constantly and raises the ambient temperature of the capacitor, so that there is a problem that the life of the capacitor is deteriorated.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a resistance device that is small and does not deteriorate the life of the capacitor.

The resistance device of the present invention includes at least one first resistor connected in series to a first smoothing capacitor and a second smoothing capacitor connected in series, and a second connected in parallel to the first smoothing capacitor. A resistor, a third resistor connected in parallel to the second smoothing capacitor, and an insulating case for sealing the first, second and third resistors with a sealing material filled therein; Prepare.

According to the resistance device of the present invention, the first, second and third resistors are thermally coupled by being sealed in the insulating case. Since the first resistor and the second and third resistors have different temperature rise timings, it is possible to cool the heat generated by the other resistor when one temperature rises. Therefore, the first, second, and third resistors can be reduced in size, and the resistance device can be reduced in size. In addition, the second and third resistors constantly generate heat when used as a voltage balance resistor, but since the heat can be radiated to the first resistor, the deterioration of the life of the capacitor is suppressed. be able to. Objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

FIG. 3 is a circuit diagram of the inverter device according to the first embodiment. It is a figure which shows the temperature change of an inrush current prevention resistance and a voltage balance resistance. 1 is a perspective view of an inverter device according to a first embodiment. FIG. 3 is a side view of the inverter device according to the first embodiment. FIG. 3 is an exploded perspective view of the resistance device according to the first embodiment. 1 is a cross-sectional view of a resistance device according to a first embodiment. FIG. 6 is an exploded perspective view of a resistance device according to a second embodiment. FIG. 10 is an exploded perspective view of a resistance device according to a third embodiment. FIG. 6 is a cross-sectional view of a resistance device according to a third embodiment.

Embodiment 1 FIG.
FIG. 1 is a circuit diagram of an inverter device 100 according to the first embodiment. The inverter device 100 includes a three-phase (R phase, S phase, T phase) input power supply Pin, a rectifier circuit 10, an inrush current prevention resistor 4, an inrush current prevention relay 3, a relay drive circuit 2,

smoothing capacitors

5a and 5b, a

voltage Balance resistors

6a and 6b and an inverter 20 are provided.

The rectifier circuit 10 includes a plurality of

rectifier diodes

1a, 1b, 1c, 1d, 1e, and 1f. The rectifier diodes 1a and 1d are connected to the R phase, the rectifier diodes 1b and 1e are connected to the S phase, and the rectifier diodes 1c and 1f are connected to the T phase. The smoothing capacitor 5a and the smoothing capacitor 5b are connected in series between the positive line Lp and the negative line Ln to ensure a withstand voltage. The inrush current preventing resistor 4 is connected to the series connection body in series at the subsequent stage of the rectifier circuit 10. The inrush current prevention relay 3 is connected in parallel with the inrush current prevention resistor 4, and its on / off is controlled by the relay drive circuit 2.

The inrush current preventing resistor 4 is for limiting the charging current flowing through the smoothing

capacitors

5a and 5b. Without the inrush current preventing resistor 4, when the input power source Pin is turned on, an excessive inrush current flows to the

uncharged smoothing capacitors

5a and 5b. When the

smoothing capacitors

5a and 5b are charged, the inrush current preventing relay 3 is shifted from OFF to ON by the relay drive circuit 2, and the current that has been flowing through the inrush current preventing resistor 4 until then is passed through the inrush current preventing relay 3. To bypass the inrush current prevention resistor 4. Accordingly, no current flows through the inrush current prevention resistor 4.

Since the voltage division ratio of the

smoothing capacitors

5a and 5b depends on the leakage current of the

smoothing capacitors

5a and 5b, the applied voltage to the

smoothing capacitors

5a and 5b also varies due to variations in the leakage current. In order to suppress variation in applied voltage,

voltage balancing resistors

6a and 6b are connected in parallel to the

smoothing capacitors

5a and 5b, respectively. Simultaneously with the start of charging of the

smoothing capacitors

5a and 5b, a voltage is applied to the

voltage balance resistors

6a and 6b. However, since the current value flowing through the

voltage balance resistors

6a and 6b is relatively small, the temperature of the

voltage balance resistors

6a and 6b is It rises little by little.

The inverter 20 includes IGBTs (Insulated Gate Bipolar Transistors) 7a, 7b, 7c, 7d, 7e, 7f,

diodes

8a, 8b, 8c, 8d, 8e, 8f, and

drive circuits

9a, 9b, 9c, 9d, 9e, 9f. Is provided. The IGBT is an example of a power semiconductor element. Between the positive line Lp and the negative line Ln, there are a series circuit composed of

IGBTs

7a and 7d for switching the U phase, a series circuit composed of IGBTs 7b and 7e for switching the V phase, and IGBTs 7c and 7f for switching the W phase. Are connected to each other.

Diodes

8a, 8b, 8c, 8d, 8e, and 8f are connected in reverse parallel to the

IGBTs

7a, 7b, 7c, 7d, 7e, and 7f, respectively. The junction points of

IGBTs

7a and 7d are connected to the U-phase terminal U of the motor, the junction points of IGBTs 7b and 7e are connected to the V-phase terminal V of the motor, and the junction points of IGBTs 7c and 7f are connected to the W-phase terminal W of the motor. Drive signals are individually supplied from the

drive circuits

9a, 9b, 9c, 9d, 9e, and 9f to the gates and emitters of the

IGBTs

7a, 7b, 7c, 7d, 7e, and 7f, respectively. The

drive circuits

9a, 9b, 9c, 9d, 9e, and 9f are provided with photocouplers for optical insulation, receive control signals from an external control circuit such as a microprocessor, generate drive signals, and pass through connection terminals. Then, drive signals are supplied to the gates and emitters of the

IGBTs

7a, 7b, 7c, 7d, 7e and 7f.

FIG. 1 illustrates an inverter device 100 that converts a three-phase (R-phase, S-phase, T-phase) input power source Pin into a three-phase (U-phase, V-phase, W-phase) power output. The present invention can also be applied to various inverter devices or various converter devices. In FIG. 1, the inrush current prevention resistor 4 and the inrush current prevention relay 3 are arranged in the subsequent stage of the rectifier circuit 10. May be.

With reference to FIG. 2, the temperature change of the inrush current prevention resistor 4 and the

voltage balance resistors

6a and 6b will be described. In FIG. 2, a curve 41 shows a temperature change of the inrush current prevention resistor 4, and a curve 42 shows a temperature change of the

voltage balance resistors

6a and 6b. In the inverter device 100 of the first embodiment, the inrush current prevention resistor 4 and the

voltage balance resistors

6a and 6b are thermally coupled as will be described later with reference to FIGS. 4 and the

voltage balance resistors

6a and 6b are not thermally coupled, that is, the temperature changes in the state where it is assumed that there is no heat transfer between the inrush current prevention resistor 4 and the

voltage balance resistors

6a and 6b. .

First, the temperature change of the inrush current prevention resistor 4 represented by the curve 41 will be described. When the input power source Pin is turned on at time T = 0, the temperature of the inrush current prevention resistor 4 rapidly increases. This is because charging of the smoothing

capacitors

5a and 5b starts, and the inrush current prevention resistor 4 limits the inrush current to the smoothing

capacitors

5a and 5b. As the smoothing

capacitors

5a and 5b are charged, the current flowing through the inrush current prevention resistor 4 decreases. When the inrush current prevention relay 3 shifts from OFF to ON at time T = T1, the current bypasses the inrush current prevention resistor 4 by the inrush current prevention relay 3, so that the temperature of the inrush current prevention resistor 4 decreases. Thus, since a large current flows only in the inrush current prevention resistor 4 for a short time when the smoothing

capacitors

5a and 5b are charged, a winding resistance having a high pulse resistance is used.

Next, the temperature change of the

voltage balance resistors

6a and 6b represented by the curve 42 will be examined. When the input power source Pin is turned on at time T = 0, charging of the smoothing

capacitors

5a and 5b starts, and at the same time, a voltage is applied to the

voltage balance resistors

6a and 6b. However, since the current value flowing through the

voltage balance resistors

6a and 6b is relatively small, the temperature of the

voltage balance resistors

6a and 6b gradually increases.

Comparing the temperature changes of the inrush current prevention resistor 4 and the

voltage balance resistors

6a and 6b, the timing of temperature rise of both is different. At the time when the temperature of the inrush current prevention resistor 4 reaches a peak (T = T1), the temperature of the

voltage balance resistors

6a and 6b does not increase so much. On the other hand, when the temperature of the

voltage balance resistors

6a and 6b is high, the temperature of the inrush current preventing resistor 4 decreases after passing the peak.

3 is a perspective view of the inverter device 100, and FIG. 4 is a side view of the inverter device 100 viewed in the direction of the arrow shown in FIG. In the inverter device 100, an inrush current prevention relay 3 (not shown), smoothing

capacitors

5a and 5b, a resistor device 30A, driving

circuits

9a, 9b, 9c, 9d, 9e, and 9f (see FIG. The relay drive circuit 2 (not shown) and the rectifying module 31 and the IGBT module 32 are mounted on the lower surface. The rectifying module 31 and the IGBT module 32 are electrically connected to the printed wiring board 33 by soldering.

The rectifying module 31 is a module in which a plurality of

diodes

1 a, 1 b, 1 c, 1 d, 1 e, and 1 f are enclosed in one package, and constitutes the rectifying circuit 10. The IGBT module 32 is a module in which

IGBTs

7a, 7b, 7c, 7d, 7e, 7f and

diodes

8a, 8b, 8c, 8d, 8e, 8f are enclosed in one package. Since the rectifying module 31 and the IGBT module 32 are heat generating electronic components, a heat sink 34 is attached to them and cooled by the heat sink 34.

The configuration of the resistance device 30A will be described. FIG. 5 is an exploded perspective view of the resistance device 30A, and FIG. 6 is a cross-sectional view taken along the line AA in a state in which the resistance device 30A of FIG. 5 is assembled. The resistance device 30 A includes

resistors

61, 62 a, 62 b and an insulating case 50. The resistor 61 is used as the inrush current preventing resistor 4, and the

resistors

62a and 62b are used as the

voltage balance resistors

6a and 6b.

The insulating case 50 has a rectangular parallelepiped shape, and has

grooves

53, 54, and 55 that are recessed from the upper surface. A resistor 61 is disposed in the groove 53, and

resistors

62a and 62b are disposed in the

grooves

54 and 55, respectively. In other words, the groove 53 is a first groove in which the resistor 61 is disposed, the groove 54 is a second groove in which the resistor 62a is disposed, and the groove 55 is a third groove in which the resistor 62b is disposed. It is a groove. Thereby, the positioning of the

resistors

62a, 62b, and 62c in the insulating case 50 can be easily performed, and the positional variation of the

resistors

62a, 62b, and 62c is suppressed. The

resistors

61, 62a, 62b are cylindrical. An electrode terminal 52c is connected to both ends of the resistor 61, an electrode terminal 52a is connected to both ends of the resistor 62a, and an electrode terminal 52b is connected to both ends of the resistor 63b.

In FIG. 5, the size of the inrush current prevention resistor 4 is made larger than that of the

voltage balance resistors

6a and 6b, and the groove 53 for arranging the inrush current prevention resistor 4 is replaced with the groove 54 for arranging the

voltage balance resistors

6a and 6b. It is larger than 55. Accordingly, it is possible to prevent the inrush current prevention resistor 4 from being mistakenly disposed in the

grooves

54 and 55 for arranging the

voltage balance resistors

6a and 6b.

With the

resistors

61, 62a, 62b disposed in the

grooves

53, 54, 55, the

grooves

53, 54, 55 are filled with a sealing material 56 such as cement. Thus, the

resistors

61, 62a and 62b are sealed in the insulating case 50 and thermally coupled. That is, the inrush current preventing resistor 4 and the

voltage balance resistors

6a and 6b are thermally coupled. As shown in FIG. 6, the sealing amount of the sealing material 56 is adjusted so that the sealing surface, that is, the upper surface of the sealing material 56 is lower than the upper surface of the insulating case 50. Thereby, the creeping distance between the

electrode terminals

52a, 52b, and 52c is increased by the distance between the upper surface of the insulating case 50 and the sealing surface of the sealing material 56. Similarly, the creepage distance between the

electrode terminals

52a, 52b, and 52c and the housing 40 to which the resistance device 30A is attached also becomes long.

The

electrode terminals

52a, 52b, and 52c protrude upward from the insulating case 50, and the protruding portion is connected to the printed wiring board 33 using a connector such as a flat connector and wiring (see FIG. 3). More specifically, the electrode terminal 52c is wire-connected to connection points 70c shown at both ends of the resistor 61 in FIG. The electrode terminal 52a is wire-connected to connection points 70a shown at both ends of the resistor 62a in FIG. The electrode terminal 52b is wire-connected to connection points 70b shown at both ends of the resistor 62b in FIG. If the shape or size is changed between the electrode terminal 52c and the

electrode terminals

52a and 52b, the

electrode terminals

52a, 52b and 52c are connected to the

connection points

70a, 70b and 70c using a connector such as a flat connector. Erroneous connection can be prevented.

The metal fitting 51 provided with the screw hole 57 is attached to the resistance device 30A. By screwing the metal fitting 51 to the housing 40, the resistance device 30 A is fixed with the bottom surface thereof in direct contact with the housing 40. Thereby, since the heat generated by the resistance device 30A can be released to the housing 40 of the inverter device 100, the size of the resistance device 30A can be reduced. The resistance device 30 A may be attached to the side surface of the housing 40 or the heat sink 34 in addition to being attached to the bottom surface of the housing 40, and the same effect is obtained. Further, the fixing method of the resistance device 30A is not limited to the above. The resistance device 30 A may be attached to the printed wiring board 33 by inserting the

electrode terminals

52 a, 52 b, 52 c into through holes provided in the printed wiring board 33 and soldering to the printed wiring board 33.

As described above, the resistance device 30A according to the first embodiment includes the first smoothing capacitor 5a that is the first smoothing capacitor connected in series and the smoothing capacitor 5b that is the second smoothing capacitor. A resistor 61 that is a resistor, a resistor 62a that is a second resistor connected in parallel to the smoothing capacitor 5a, a resistor 62b that is a third resistor connected in parallel to the smoothing capacitor 5b, and a resistor An insulating case 50 that seals the

bodies

61, 62a, 62b with a sealing material 56 filled therein is provided. Thereby, the inrush current prevention resistor 4 and the

voltage balance resistors

6a and 6b are thermally coupled. As shown in FIG. 2, the temperature rise timing of the inrush current prevention resistor 4 and the

voltage balance resistors

6a and 6b are different, and when the temperature of the inrush current prevention resistor 4 is raised, the voltage balance resistors 6a, The temperature of 6b has not risen. Accordingly, the heat generated in the inrush current prevention resistor 4 is transferred to the

voltage balance resistors

6a and 6b, so that the same effect as that of increasing the heat capacity of the inrush current prevention resistor 4 is obtained. The rise is suppressed. Further, when the temperature of the

voltage balance resistors

6a and 6b is rising, the temperature of the inrush current preventing resistor 4 is not rising. Accordingly, the heat generated in the

voltage balance resistors

6a and 6b moves to the inrush current prevention resistor 4, so that the same effect as that of increasing the heat capacity of the

voltage balance resistors

6a and 6b can be obtained, and the

voltage balance resistors

6a and 6b. Temperature rise is suppressed. As a result, the inrush current preventing resistor 4 and the

voltage balance resistors

6a and 6b can be reduced in size. Moreover, since the temperature rise of

voltage balance resistance

6a, 6b is suppressed, the raise of the ambient temperature of smoothing

capacitor

5a, 5b is suppressed, and the lifetime deterioration of smoothing

capacitor

5a, 5b is suppressed.

Embodiment 2. FIG.
FIG. 7 is an exploded perspective view of the resistance device 30B according to the second embodiment. Since the resistance device 30B is a partial modification of the resistance device 30A of the first embodiment, differences from the resistance device 30A of the first embodiment will be described below. In the resistance device 30A of the first embodiment, as shown in FIG. 5, the

resistors

62a and 62b to be the

voltage balance resistors

6a and 6b are arranged in

different grooves

54 and 55 of the insulating case 50. In contrast, in the resistance device 30B according to the second embodiment, the ends of the

resistors

62a and 62b having the same potential are connected by the common electrode terminal 52d, and the

resistors

62a and 62b are arranged in the same groove 58. In other respects, the resistance device 30B is the same as the resistance device 30A of the first embodiment.

In the resistor device 30B of the second embodiment, one end of the resistor 62a and one end of the resistor 62b are connected by a common electrode terminal 52d, and the insulating case 50 is a groove that is a first groove in which the resistor 61 is disposed. 53 and a groove 58 which is a second groove in which the resistors 62 and 63 are disposed. The resistance device 30B can be downsized and the number of components can be reduced by using the common electrode terminal 52d at the same potential end of the

resistors

62a and 62b. In addition, since the

voltage balance resistors

6a and 6b can be mounted at a closer distance, the

voltage balance resistors

6a and 6b receive heat to reduce the temperature difference between them. Accordingly, it is possible to reduce variations in the resistance values of the

voltage balance resistors

6a and 6b accompanying the temperature changes of the

resistors

62a and 62b.

Embodiment 3 FIG.
FIG. 8 is an exploded perspective view of the resistance device 30C of the third embodiment, and FIG. 9 is a cross-sectional view taken along the line BB in a state where the resistance device 30C of FIG. 8 is assembled. Hereinafter, the configuration of the resistance device 30C will be compared with the resistance device 30B of the second embodiment, and differences will be described. The configuration of the resistance device 30C not specifically mentioned in the following description is the same as that of the resistance device 30B of the second embodiment.

In the resistor device 30B of the second embodiment, one resistor 61 constitutes the inrush current preventing resistor 4. However, in the resistor device 30C, the two resistors 61 are connected in series or in parallel to form the inrush current preventing resistor 4. Constitute. In the resistance device 30B of the second embodiment, the resistor 61 constituting the inrush current preventing resistor 4 and the

resistors

62a and 62b constituting the

voltage balance resistors

6a and 6b are arranged in

different grooves

53 and 58, respectively. However, in the resistance device 30 C, the

resistors

61, 62 a, and 62 b are disposed in the same groove 59 provided in the insulating case 50. The groove 59 is a recess that is recessed from the upper surface of the insulating case 50.

Two protrusions 60 are provided on the bottom surface of the groove 59 from one end to the other end. Due to the two protrusions 60 arranged in this manner, the groove 59 of the insulating case 50 has a region sandwiched between the two protrusions 60, a region sandwiched between one protrusion 60 and the side surface of the groove 59, and the other protrusion. 60 and the region between the sides of the groove 59 are divided into three regions.

Resistors

62a and 62b are disposed in the region sandwiched between the two protrusions 60, and two resistors 61 are disposed in the other regions so as to sandwich the

resistors

62a and 62b. Due to the protrusion 60, the resistor 61 and the

resistors

62a and 62b are not in contact with each other, and positioning of the

resistors

61, 62a and 62b in the groove 59 is performed.

In the state where the

resistors

61, 62a, 62b are arranged in the groove 59, the groove 59 is filled with a sealing material 56 such as cement. As shown in FIG. 9, the sealing amount of the sealing material 56 is adjusted so that the sealing surface, that is, the upper surface of the sealing material 56 is lower than the upper surface of the insulating case 50. Thus, the

resistors

voltage balance resistors

6a and 6b are thermally coupled.

By providing a protrusion 60 on the bottom surface of the groove 59 of the insulating case 50 and positioning the

resistors

61, 62a, 62b by the protrusion 60, the material of the insulating case 50 is reduced as compared with the first and second embodiments, and manufacturing is easy. It becomes possible to do. Further, the

resistors

62a and 62b constituting the

voltage balance resistors

6a and 6b are sandwiched and the resistor 61 constituting the inrush current preventing resistor 4 is disposed, whereby the inrush current preventing resistor 4 and the

voltage balance resistors

6a and 6b are arranged. Since the thermal coupling property is improved, the heat generated by the

resistors

62a and 62b is cooled by the resistor 61, and the heat generated by the resistor 61 is cooled by the

resistors

62a and 62b.

In the present embodiment, the inrush current prevention resistor 4 is constituted by a plurality of resistors 61, and the resistors 61 are arranged on both sides of the

resistors

62a and 62b constituting the

voltage balance resistors

6a and 6b. However, the inrush current prevention resistor 4 is constituted by one resistor 61, the voltage balance resistor 6a is constituted by a plurality of resistors 62a, the voltage balance resistor 6b is constituted by a plurality of resistors 62b, and the resistor 61 is sandwiched therebetween. The

resistors

62a and 62b may be arranged. However, since the

resistors

62a and 62b are at a higher temperature than the resistor 61, the temperature of the resistance device 30C can be equalized by disposing the

resistors

62a and 62b closer to the center of the insulating case 50. .

In the present invention, it is possible to freely combine the respective embodiments within the scope of the invention, and to appropriately modify and omit the respective embodiments.

1a, 1b, 1c, 1d, 1e, 1f rectifier diode, 2 relay drive circuit, 3 inrush current prevention relay, 4 inrush current prevention resistor, 5a, 5b smoothing capacitor, 6a, 6b voltage balance resistor, 7a, 7b, 7c, 7d, 7e, 7f IGBT, 8a, 8b, 8c, 8d, 8e, 8f diode, 9a, 9b, 9c, 9d, 9e, 9f drive circuit, 10 rectifier circuit, 20 inverter, 30A, 30B, 30C resistance device, 31 Rectification module, 32 IGBT module, 33 printed wiring board, 34 heat sink, 40 housing, 51 metal fittings, 52a, 52b, 52c, 52d electrode terminals, 53, 54, 55, 58, 59 grooves, 56 sealing material, 57 screws hole.

Claims

At least one first resistor (61) connected in series to a first smoothing capacitor (5a) and a second smoothing capacitor (5b) connected in series;
A second resistor (62a) connected in parallel to the first smoothing capacitor (5a);
A third resistor (62b) connected in parallel to the second smoothing capacitor (5b);
An insulating case (50) for sealing the first, second and third resistors (61, 62a, 62b) with a sealing material (56) filled therein;
Resistance device (30A).
Electrode terminals (52a, 52b, 52c) are connected to the first, second and third resistors (61, 62a, 62b),
The electrode terminals (52a, 52b, 52c) protrude from the upper surface of the insulating case (50),
The upper surface of the sealing material (56) filled in the insulating case (50) is below the upper surface of the insulating case (50).
The resistance device (30A) according to claim 1.
The insulating case (50) is provided with at least one groove (53, 54, 55) recessed from the upper surface of the insulating case (50),
The first, second and third resistors (61, 62a, 62b) are disposed in the grooves (53, 54, 55).
The resistance device (30A) according to claim 1 or 2.
The groove is
A first groove (53) in which the first resistor (61) is disposed;
A second groove (54) in which the second resistor (62a) is disposed;
A third groove (55) in which the third resistor (62b) is disposed,
The resistance device (30A) according to claim 3.
One end of the second resistor (62a) and one end of the third resistor (62b) are connected by a common terminal (52d),
The groove is
A first groove (53) in which the first resistor (61) is disposed;
A second groove (58) in which the second and third resistors (62a, 62b) are disposed,
The resistance device (30B) according to claim 3.
The first, second and third resistors (61, 62a, 62b) are disposed in one groove (59) formed in the insulating case (50),
The insulating case (50) has a protrusion (60) for positioning the first, second and third resistors (61, 62a, 62b) on the bottom surface of the groove (59).
The resistance device (30C) according to claim 3.
A plurality of the first resistors (61) are connected in series or in parallel, and are disposed so as to sandwich the second and third resistors (62a, 62b).
The resistance device (30C) according to any one of claims 1 to 6.
The second and third resistors (62a, 62b) are disposed with the first resistor (61) interposed therebetween,
The resistance device according to any one of claims 1 to 6.
The resistance device according to claim 1 is provided.
Inverter device (100).