JPH11136960A - Three-phase inverter circuit module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a three-phase inverter circuit module that can accurately control a motor under a high electromagnetic noise environment, and that has a superior property of being mounted on a vehicle despite of a large-capacity electrolytic capacitors for smoothing. SOLUTION: A three-phase inverter circuit for controlling a motor, and a control circuit for controlling the three-phase inverter circuit are mounted to a substrate 7. Also, a capacitor device 35 for smoothing an input current is connected to the substrate 7 by a bussbar or the like. The capacitor device 35 is provided with a plurality of cylindrical electrolytic capacitors which are connected to one another in parallel, and a flat-can-shaped metal capacitor case 357 that arranges each cylindrical electrolytic capacitor in one line in a direction where the substrate is extended for accommodating, covers the substrate 7, and is connected to the substrate 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase inverter circuit module for controlling, for example, a traveling motor of an electric vehicle, and more particularly to a three-phase inverter circuit module for controlling the driving of a traveling motor of a hybrid electric vehicle.

[0002]

2. Description of the Related Art A three-phase inverter device can recover rotational energy of a load as electric power to a DC power source side by a regenerative operation at the time of braking. Therefore, the three-phase inverter device is widely used for motor drive control such as a drive motor of an electric vehicle. ing. A conventional three-phase inverter device used for controlling a traveling motor of a hybrid electric vehicle will be described with reference to FIG.

[0003] 1 is a main battery, 3 is a current detection circuit module, 4 is a three-phase inverter circuit module, and 5 is a running motor. In the three-phase inverter circuit module 4, 19 to 24 are IGBTs,
Is a high side switch, and 20, 22, and 24 are low side switches. The high-side switch 19 and the low-side switch 20 connected in series constitute a first phase switch circuit 4a, and the high-side switch 21 and the low-side switch 22 connected in series constitute a second phase switch circuit 4b. The high-side switch 23 and the low-side switch 24 connected in series constitute a third phase switch circuit 4 c, and each of the phase switch circuits 4 a to 4 c is supplied with power from the main battery 1. 25-
Numeral 30 denotes flywheel diodes which are individually connected in parallel with the IGBTs 19 to 24, for supplying a return current to the running motor 5 which is a three-phase AC motor which is an inductive load.

The output terminal of the first phase switch circuit 4a which is a connection point between the high side switch 19 and the low side switch 20, and the output terminal 4 of the second phase switch circuit which is a connection point between the high side switch 21 and the low side switch 22.
b and the output terminal of the third phase switch circuit 4c, which is the connection point of the high-side switch 23 and the low-side switch 24, are busbars 41 to 43 and an insulating cable 44.
Through 46 are individually connected to the respective phase terminals of the traveling motor 5.

[0005] 40 is a three-phase inverter circuit module 4
The microcomputer is a control circuit having a microcomputer structure built therein. Based on a detected motor current from a current detection circuit module 3 described later or a command signal from an external controller, etc.
The GBTs 19 to 24 are intermittently controlled to generate a three-phase AC voltage. Since the operation itself of the controller 40 is well known,
Description is omitted.

The current detecting circuit module 3 includes a current detecting section 31 for detecting a U-phase current, a current detecting section 32 for detecting a W-phase current, and amplifying the current detected by the current detecting sections 31 and 32. And a peripheral circuit unit 33 for supplying power to the current detection units 31 and 32. The reactor 34 and the smoothing capacitor 35 constitute a well-known smoothing circuit to average the power supply current from the main battery 1 to the three-phase inverter circuit module 4, thereby suppressing the shortening of the life of the main battery.

[0007]

However, it has been found that the conventional three-phase inverter device for driving the running motor of the hybrid electric vehicle described above has the following problems to be improved. That is, in a hybrid electric vehicle, since a large electromagnetic wave noise source such as an engine or a star motor exists near the three-phase inverter device, the reliability of the traveling motor control due to external noise such as the electromagnetic wave noise is increased. There was a possibility that the property was reduced. Since the operation of the running motor is the basis of vehicle operation, it is necessary to sufficiently secure the electromagnetic wave noise resistance of the three-phase inverter device for controlling the driving of the running motor. In particular, the hybrid electric vehicle needs to be able to exhibit excellent running motor control performance even in a high electromagnetic wave noise environment.

The inventors of the present invention have analyzed the three-phase inverter device for controlling driving of a driving motor under a high electromagnetic wave noise environment such as a hybrid electric vehicle based on the above recognition, and analyzed the following problems. Was found to exist. That is, in the conventional three-phase inverter device, the output current is detected by a Hall element capable of detecting the precision with high accuracy, but the resistance change of the Hall element is extremely small. for that reason,
The weak output voltage output from the Hall element is greatly amplified by a bridge circuit configuration or the like and transmitted to the controller 40.

Therefore, electromagnetic noise is superimposed on the output signal line 47 for transmitting the signal voltage from the Hall element to the peripheral circuit section 33 for amplification and the output signal line 48 for transmitting the signal voltage from the peripheral circuit section 33 to the controller 40. And the detected output current value S
It has been found that a problem arises in that the N ratio decreases and the control accuracy of the traveling motor 5 decreases. The output signal line 4
Similarly to the control circuits 7 and 48, the control circuit including the microcomputer is liable to malfunction due to electromagnetic wave noise, and it is important to improve its noise resistance.

The present invention has been made in view of the above problems, and has as its object to realize a three-phase inverter circuit module capable of controlling a motor with high accuracy even in a high electromagnetic noise environment. Next, the smoothing capacitor is important in reducing the current fluctuation due to the switching of the three-phase inverter circuit and extending the life of the main battery. As is well known, the capacitor has a remarkably large size due to the increase in its capacity. Therefore, the space for accommodating the three-phase inverter circuit module in which the smoothing capacitor is integrated becomes large, and it becomes difficult to place and arrange various devices in the space where the electric vehicle is mounted. In particular, in the frequency band of the smoothing capacitor of the three-phase inverter circuit module, the electrolytic capacitor is most suitable in terms of capacity and loss, but since the electrolytic capacitor usually has a cylindrical shape,
The overall shape becomes a substantially triangular prism shape (the shape is greatly deformed from a substantially rectangular parallelepiped shape having the best space occupancy), the accommodating property is deteriorated, and the required space becomes larger than its substantial volume.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to realize a three-phase inverter circuit module excellent in vehicle mountability despite having a large-capacity electrolytic capacitor for smoothing. And

[0012]

According to a three-phase inverter circuit module of the present invention, a three-phase inverter circuit for motor control and a plurality of control circuits for controlling the three-phase inverter circuit are integrated with one another. Mounted on a substrate. Also, a capacitor device for input current smoothing is directly or indirectly coupled to the substrate.

In this configuration, in particular, the capacitor device covers a plurality of cylindrical electrolytic capacitors connected in parallel with each other and the cylindrical electrolytic capacitors in a state of being arranged in a line in the extending direction of the substrate. A flat can-shaped metal capacitor case directly or indirectly coupled to the substrate. With this configuration, the following operation and effect can be obtained.

The control circuit is a signal processing IC in which an extremely large number of transistors are integrated, and has much lower electromagnetic wave noise resistance than a three-phase inverter circuit. However, malfunction due to the electromagnetic wave noise makes the motor controllability unstable, so that it is necessary to significantly improve the electromagnetic wave noise resistance performance of the control circuit. The flat can-shaped metal capacitor case adopted in this configuration is extended close to the control circuit so as to cover the entire surface thereof. Therefore, the flat can-shaped metal capacitor case has good shape and posture. It can function as an electromagnetic shield of a simple control circuit.

Further, a plurality of small cylindrical electrolytic capacitors can be arranged in a row in this metal capacitor case, and can be attached and detached as if handling a single capacitor. It is possible to improve the mountability of the module while maintaining substantially the same workability as compared with the case where one capacitor is provided.
In addition, conventionally, the module has a generally triangular cross-section, resulting in waste of the accommodation space. However, in the present configuration, the whole has a substantially rectangular parallelepiped shape, so that this waste can be eliminated. .

After all, according to this configuration, it is possible to realize a three-phase inverter circuit module having excellent accommodating properties and electromagnetic wave shielding properties. According to a second aspect of the present invention, in the three-phase inverter circuit module according to the first aspect, the semiconductor current detecting element is further mounted on the substrate and magnetically detects an output current, and the semiconductor current detecting element is mounted on the substrate. And a sensor signal amplifying circuit for amplifying the output signal voltage.

The semiconductor current detecting element, the sensor signal amplifying circuit, and the wiring between them, and the wiring connecting the sensor signal amplifying circuit and the control circuit handle analog signal voltages, so that they are particularly susceptible to electromagnetic wave noise. Therefore, further stability of the motor control operation can be realized by the electromagnetic wave shielding by the metal capacitor case of this configuration.

According to the third aspect of the present invention, the three-phase inverter circuit module according to the first or second aspect is further used for controlling the driving of a traveling motor of a hybrid electric vehicle. That is, the hybrid electric vehicle is mounted together with an engine (ignition type internal combustion engine). With this configuration, it is possible to prevent the running motor from malfunctioning due to the electromagnetic wave noise generated from the ignition type internal combustion engine, and to further stabilize the running control of the noise source vehicle without adding an electromagnetic wave shield which is complicated and increases the body weight and the like. Can be

In particular, the driving mode of a hybrid electric vehicle
When driving at high speeds, the motor is operated at a much higher frequency than a conventional commercial frequency motor, so that the three-phase inverter circuit needs to be intermittently controlled at a much higher speed, and the signal voltage output from the semiconductor current detecting element is reduced. Relatively high frequency components also need to be used as signal components. Therefore, the band of the signal voltage output from the semiconductor current detecting element is wide, and the noise power is correspondingly increased. Further, the electromagnetic wave noise becomes stronger as the frequency becomes higher, so that its influence is further increased.

According to a fourth aspect of the present invention, there is provided the three-phase inverter circuit module according to any one of the first to third aspects, further comprising a substrate, particularly, an inverter circuit board on which the three-phase inverter circuit is mounted. It is electrically insulated and joined to a metal cooling block. That is, the three-phase inverter circuit is cooled by being joined to a metal cooling block for heat dissipation and heat sink. With this arrangement, the above-described circuits mounted on the board are provided with a cooling block and a metal capacitor case.
Therefore, the electromagnetic noise resistance performance can be further improved.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a high side switch and a low side switch of a three-phase inverter circuit, MOS, bipolar, SIT, IGBT and the like can be adopted. The three-phase inverter circuit can have a fourth phase inverter circuit for controlling the neutral current of the star-connected motor.

The cylindrical electrolytic capacitor according to the present invention may have a flattened cylindrical shape other than a perfect cylindrical shape.

[0023]

FIG. 1 shows a circuit of a hybrid electric vehicle using a three-phase inverter circuit module according to the present invention. However, components having the same main functions as those of the conventional three-phase inverter device shown in FIG. 7 are denoted by the same reference numerals for easy understanding. Since this three-phase inverter circuit module is a slightly modified version of the conventional three-phase inverter device shown in FIG. 7, only the changed points will be described below.

In this embodiment, the current detection circuit module 3 shown in FIG. 7 is omitted, and a current detection circuit 300 is mounted in the three-phase inverter circuit module 4 instead. Reference numerals 41 to 43 denote bus bars constituting the output conductor of the present invention. The current detection circuit 300 is provided with a busbar 41
Current detector 301 for detecting a U-phase current flowing through the bus, and a current detector 302 for detecting a W-phase current flowing through the bus bar 43.
And a peripheral circuit unit (including a sensor signal amplifier circuit according to the present invention) 3 that amplifies the current detected by the current detection units 301 and 302 and supplies power to the current detection units 301 and 302.
The peripheral circuit unit 303 is mounted on a control circuit board described later together with the control circuit 40.

The principle configuration of the current detection circuit 300 will be described. The bus bar 41 includes a magnetic core 30 having a gap.
11, a Hall element (semiconductor current detecting element, not shown) is accommodated in the gap of the magnetic core 3011, and the output terminal of the Hall element forms a part of the peripheral circuit section 303. It is amplified by the amplifier. That is, the magnetic core 3011 and the Hall element are
1. The configuration of the current detection unit 302 is the same as that of the current detection unit 301, and a description thereof will be omitted.

FIG. 2 is a schematic perspective view of the three-phase inverter circuit module. The cooling block 6 made of aluminum has a substantially rectangular box shape with a shallow bottom opening, and an inverter circuit board (not shown) is provided therein so as to be electrically insulated. Three windows are opened in the side wall 61 in front of the cooling block 6, and bus bars 41 to 41 forming output conductors from these windows.
43 project individually and in parallel. Three magnetic cores 3011 made of ferrite are individually fitted and bonded to the window, and bus bars 41 to 43 individually penetrate the respective magnetic cores 3011 and protrude horizontally, and their tips are connected to the three-phase inverter circuit. It constitutes the AC output end of the module.

The upper end opening of the cooling block 6 is sealed by a control circuit board 7 parallel to the bottom plate of the cooling block 6, and both are fixed with screws. An IC is mounted and wired. 10
Is a connector for connection to an external ECU (not shown). Reference numeral 3016 denotes a protective resin member covering the Hall element. On the upper surface of the side wall of the cooling block 6, a thread for securing a gap is provided.
A smoothing capacitor (a capacitor device according to the present invention) 35 is fixed with the filter 12 interposed therebetween.

As shown in FIG. 3, the smoothing capacitor 35 includes a metal capacitor case 357 made of a flat aluminum case that houses therein three or more small cylindrical electrolytic capacitors 351 to 356 arranged in a line. It shields the control circuit board 7 and protects the control circuit board 7 and shields its electromagnetic waves. 358 is a mounting bracket, 3
59 is a positive terminal, and 360 is a negative terminal.

Therefore, in this embodiment, the control circuit 4 includes a cooling block 6 for cooling the three-phase inverter circuit 4 and a flat smoothing capacitor 35 for protecting the main battery.
0, current detectors 301 and 302, sensor signal amplifier circuit 3
Since the area around the wires 03 and the wiring between them are electromagnetically shielded, accurate running motor control can be realized even in a high electromagnetic wave noise environment close to the ignition type engine.

Although the three-phase inverter circuit module shown in FIG. 2 is finally housed in a resin case and fastened and fixed to the vehicle, the illustration is omitted because it is not related to the gist of the present invention. I do. (Modification 1) A modification of the above embodiment will be described with reference to FIG.

In this modified embodiment, the cylindrical electrolytic capacitors 361 to 363 are changed from the complete cylindrical shape shown in FIG. 3 to a flattened cylindrical shape obtained by crushing it. In this way, the metal capacitor case 357 can be further flattened, and the mountability on a vehicle can be improved. (Modification 2) A modification of the above embodiment will be described with reference to FIG.

In this modification, the positive terminals 371 and 373 of the cylindrical electrolytic capacitors 361 to 363 shown in FIG.
375 and the negative terminals 372, 374, and 376 are DIP
It has a lead shape of an IC package, and is excellent in assembling property to a bus bar extending below the IC package. (Modification 3) A modification of the above embodiment will be described with reference to FIG.

In this modification, a metal capacitor case 35 is attached to a resin block 60 instead of the cooling block 6.
This is a modification of the assembly structure. That is, the positive terminals 371, 373, and 375 are fastened to the block 60 by the mounting bracket 501 also serving as a bus bar, and the negative terminals 372, 374, and 376 are fastened to the block 60 by the mounting bracket 502 also serving as a bus bar. , 502 are provided to be electrically insulated from each other.

In this way, since the bus bar or the connection conductor also serves as the mounting bracket, the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a traveling motor control device for a hybrid electric vehicle employing a three-phase inverter circuit module according to the present invention.

FIG. 2 is a schematic perspective view of the three-phase inverter circuit module shown in FIG.

FIG. 3 is a schematic perspective view of the smoothing capacitor 35 shown in FIG. 2;

4 is a schematic perspective view of a modification of the smoothing capacitor 35 shown in FIG.

5 is a schematic perspective view of a modification of the smoothing capacitor 35 shown in FIG.

FIG. 6 is a schematic perspective view of a modification of the three-phase inverter circuit module shown in FIG.

FIG. 7 is a circuit diagram showing a traveling motor control device of a hybrid electric vehicle employing a conventional three-phase inverter circuit module.

[Explanation of symbols]

4 is a three-phase inverter circuit, 40 is a control circuit, 7 is a control circuit board (substrate), 35 is a capacitor device, and 351 to 351
56 is a cylindrical electrolytic capacitor, 357 is a metal capacitor case, 301 and 302 are current detecting sections (semiconductor current detecting elements), 303 is a sensor signal amplifier circuit, and 6 is a metal cooling block.

Claims (4)

[Claims] 1. A three-phase inverter circuit in which a high-side switch and a low-side switch are connected in series to form a three-phase inverter circuit and which are connected in parallel to each other to supply power to a motor; A control circuit for intermittently controlling the three-phase inverter circuit based on the three-phase inverter circuit; one or more integrated substrates on which the three-phase inverter circuit and the control circuit are mounted; and the three-phase inverter integrated with the substrate. A three-phase inverter circuit module comprising: a capacitor device for input current smoothing connecting a pair of DC input terminals of a circuit; wherein the capacitor device includes a plurality of cylindrical electrolytic capacitors connected in parallel with each other; The electrolytic capacitors are accommodated in a state where they are arranged in a line in the extending direction of the substrate, and the base is placed in a posture covering the substrate. A three-phase inverter circuit module, comprising: a flat can-shaped metal capacitor case coupled to a plate. 2. The three-phase inverter circuit module according to claim 1, wherein said semiconductor current detecting element is mounted on said substrate and magnetically detects said output current, and said semiconductor current detecting element is mounted on said substrate. A three-phase inverter circuit module, comprising: a sensor signal amplifier circuit that amplifies an output signal voltage. 3. The three-phase inverter circuit module according to claim 1, wherein a driving motor of the hybrid electric vehicle is drive-controlled. 4. An outer surface of the substrate is joined to a metal cooling block so as to be electrically insulated, and the capacitor device extends along the substrate on the opposite side of the cooling block across the substrate. The three-phase inverter circuit module according to any one of claims 1 to 3, wherein: