JPH04193001A - Grounding unit in driver for electric vehicle - Google Patents

Abstract

PURPOSE:To absorb higher harmonics produced from an armature winding by disposing a metal duct between the box body of a controller incorporating semiconductor elements and the stator of a driving motor and then coupling the metal duct, at the opposite ends thereof, with the box body of the controller and the frame of the stator, respectively. CONSTITUTION:DC current is collected by a current collector 1 through a switch 2 and then converted into three-phase VVVF current through semiconductor elements built in a controller 3. Thus produced AC power is then fed through a wiring 5, laid in a metal duct 6, to the stator of an induction motor 4 thus operating an electric vehicle. The wiring duct for shielding the wiring 5 is coupled through a grounding wire 21 with the box body 3a of the controller at one end and through a grounding wire 20 with the stator frame 4a of the motor 4 at the other end. The box body 3a is further coupled through a grounding wire 11 with the body 7. The body 7 is grounded through a body grounding wire 12 and a feedback circuit, i.e., a wheel 10, to a rail. According to the constitution, higher harmonic currents, produced in the armature winding of the motor 4, flow as shown by arrows B and absorbed resulting in prevention of external induction trouble.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grounding device for an electric vehicle drive device in which a control device using a power semiconductor device drives and controls an electric motor.

[Conventional technology]

Figure 4 shows, for example, the Institute of Electrical Engineers of Japan Technical Report (Part 1) No. 251.
FIG. 2 is a configuration diagram showing a grounding device of a conventional electric vehicle drive device shown in "AC motor drive/inverter control system for electric vehicle". In the figure, 1 is a current collector such as a pantograph that collects power from a feeder line such as an overhead line, 2 is a switch that is important for the main circuit, and 3 is composed of an iGTo (gate turn-off) thyristor, etc., which controls the conversion of DC to AC. 3
This control device includes a phase inverter and is housed in a box 3a made of metal. This is a 3-phase induction motor that is a 4Fi drive motor, and 4a is the stator frame. 5 is the control device 3
This wiring connects the induction motor number and the induction motor number, and is shielded by a wiring duct 6 made of a conductive metal material. One end of the wiring duct 6 is connected to the box body. Reference numeral 7 denotes the car body of the electric car, 8 a grounding wire between the stator frame 4a and the car body 7, 9 a grounding switch, and 10 a return circuit to the rails of the car, which is made up of a grounding brush, wheels, and the like. 11 is a grounding wire between the control device box 3a and the vehicle body 7; 12 is a return circuit 10;
This is a means of grounding the vehicle body at the same potential.

Next, the operation of the above conventional device will be explained.

A DC voltage is collected from a collector 1 and a switch 2 is turned on to apply the DC voltage to a three-phase inverter of a control device 3. As a result, the inverter operates to generate a three-phase AC voltage, drive and control the induction motor 4, and adjust the speed of the vehicle. The switching operation converts the DC voltage into a three-phase variable voltage, variable frequency AC voltage.

The details of the operation of this control device 3 are explained in the above-mentioned document and are omitted here.

When grounding the control device box 3a and the stator frame 4a of the induction motor 4 to the vehicle body 7, in order to make the potential with the vehicle body 7 the same,
In addition, in order to absorb harmonic currents generated from various parts of the circuit into the inverter section, the grounding wire 8°11 is used to ground the vehicle body 7, and the vehicle body 7 is connected to either the positive or negative side of the power supply circuit (the diagram shows the negative case). A vehicle body grounding means 12 is provided for grounding the vehicle body.

Due to the switching control by the control rectifier of the power semiconductor device of the control unit @3, harmonic current generated in the stator winding of the induction motor 4 is caused to flow between the stator' winding and the stator frame 4a. It also leaks out of the wiring 5 through the capacitance that exists between them.

The path through which harmonic current flows will be explained with reference to FIG. In particular, as one of the paths through which harmonic current flows, J! There is motive 4. In the figure, 13 is the stator winding of the induction motor 4;
14 is a capacitance existing between this stator winding and the stator frame 4a. The harmonic current flows as shown by arrow A from the fixed prewinding 1i13 to the capacitance 14. Ground wire 8 of stator frame 4a
, passes through the vehicle body 7, passes through the ground @ll of the box body 3a, and is absorbed into the inverter of the control device 3. Here, since both liquid ground wires s and 1.1 pass through the car body 7 on the way, the connection part to the car body 7 is made as close as possible to reduce the leakage of harmonic current to other sources, and also to reduce the leakage to the induction motor 4. A wiring 5 is passed through a wiring duct 6.

[Issues that the investigation seeks to solve]

In the conventional grounding device of the electric vehicle drive device as described above, the control section f3 and the induction chamber! 114 and the wiring 5 to the wiring duct 6
Although the wiring duct 6 is connected at one end to the control device box 3a, it is not possible to prevent the flow of harmonic current noise, causing the problem of malfunctioning of signal equipment on the ground. There was a dot.

This invention was made to solve the above-mentioned problems, and its purpose is to provide a grounding device for electric vehicle drive equipment that eliminates leakage of harmonic current and prevents malfunctions of signal equipment on the ground. It is said that

[Failure to solve the problem]

A grounding device for a drive device of an electric vehicle according to the present invention connects one end of a wiring duct made of a conductive metal material between a control device and a drive motor to a control device box, and the other end to a stator frame. The harmonic current generated in the armature winding is directly absorbed into the semiconductor device control section without passing through the vehicle body. The harmonic current generated is absorbed into the semiconductor device control section by the wiring duct without passing through the vehicle body, preventing any influence on the outside, and harmonic current flowing from the control section to the drive motor in the wiring duct. On the other hand, since the harmonic currents flow in the opposite direction through the wiring duct, they cancel each other out, and the influence of the harmonic current itself is also reduced.

〔Example〕

FIG. 1 is a block diagram showing a grounding device for an electric vehicle drive device according to an embodiment of the present invention, and numerals 1 to 7.9 to 12 are the same as the conventional device described above. Reference numerals 20 and 21 are ground connection wires that connect the other end of the wiring duct 6 and the stator frame 4a, and the one end and the control device box body 3a, respectively. As a result, the stator frame 4a of the induction motor 4 is connected to the control device box body 3a via the wiring duct 6, and is connected to the vehicle body 7 through the ground @ll. Therefore, the harmonic current flowing through the induction motor 4 returns from the connection button to the inverter of the control device 5 through the wiring duct 6 as shown by arrow B. Since there is no vehicle body 7 on this return route, leakage to signal equipment on the ground is prevented.

Note that the other end of the wiring duct 6 may be directly connected to the stator frame 4a, and the connection wire 20 may be omitted. In addition, the wiring duct 6
The connecting wire 21 may be omitted as long as the connection of one end to the control device box body 3a provides a sufficient electrical connection.

In the above embodiment, the wiring duct 6 is sufficiently extended from the vehicle body 7, but the wiring duct 6 may come into direct contact with the vehicle body 7 due to the structure of the device.

In such a case, the procedure is as shown in FIG. 2 or 3. In FIG. 2, an insulating material 23 is provided on the outer periphery of the wiring duct 6 at a location where the support body 22 comes into contact with the wiring duct 6 to insulate it from the vehicle body 7.

In FIG. 3, the wiring duct 6 has an insulator 23 on its outer periphery.
A material coated with is used.

In this way, by providing the insulator 23 on the outer periphery of the wiring duct 6, harmonic current is transferred from the wiring duct 6 to the vehicle body 7.
It is possible to prevent leakage to signal equipment on the ground.

In the above embodiment, the induction motor 4 is driven and controlled by the control device 3 using an inverter using a gravity semiconductor device as the drive device, but other types of AC motors may be used as the drive motor. good.

The present invention is not limited to the above-mentioned example, but can also be applied to the case where a DC motor is driven and controlled by a chopper control using a power semiconductor device or a control device that performs a switching operation.

〔Effect of the invention〕

As described above, according to the present invention, the wiring duct made of conductive metal between the control device and the drive motor is connected to both, and the control device box body is grounded to the vehicle body. Harmonic current from the child winding no longer leaks into the vehicle body, preventing it from affecting external equipment.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a grounding device for an electric vehicle drive system according to an embodiment of the present invention, and Figs. 2 and 3 are diagrams for preventing the wiring duct shown in Fig. 1 from coming into contact with the vehicle body. Diagonal yc showing each example of the edge
Section 4 in the figure is a configuration diagram of a grounding device of a conventional electric positive drive device, and FIG. 5 is an explanatory diagram showing the path of harmonic current in the device of FIG. 4. 3... Control device, 3a... Box body, 4... Drive motor (induction electric $!I), 5... Wiring, 6... Wiring duct made of conductive metal material, 7. Vehicle body, 10.
Return circuit, 11...Grounding wire, 12...Vehicle body grounding means, 20.21...Grounding connection line Note that the same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] A grounding device for an electric vehicle drive device in which a drive motor is controlled by a control device having a control rectifying element, comprising: a grounding device made of a conductive metal material, one end of which is connected to a box of the control device; The other end is connected to the stator frame of the drive motor,
A wiring duct for passing the wiring between the control device and the drive motor, a grounding wire connecting the control device box body and the car body of the electric car, and a car body grounding means connecting the car body to a return circuit to the rails. A grounding device for electric vehicle drive equipment.