JP5601851B2 - Measures for inductive obstacles in power converters for vehicles - Google Patents

Description

  The present invention relates to an electric vehicle motor drive circuit for converting a single-phase AC power supplied from an overhead wire into a three-phase AC power and driving an electric motor, and more particularly to an induction failure measure for a power converter.

  FIG. 7 is a diagram showing a schematic configuration of a conventional vehicle body grounding type railway vehicle main electric circuit.

  Electric power is supplied from the substation to the main transformer 13 of each vehicle via the overhead line 10 and the pantograph 11. The current flowing through the main transformer 13 returns to the substation via the ground brush 14, the wheel 15, and the rail 36. When train A and train B exist in such a feeding system, the load current (return current) of train B may flow through the vehicle body in train A. In this case, a part of the load current of the train B flows through the ground brush 14 of the train A. As a result, a large amount of discharge or the like is generated between the ground brush 14 and the wheels, and the life of the ground brush 14 is reduced.

  FIG. 8 shows a schematic configuration of a main circuit of a railway vehicle main body of a resistance connection vehicle body grounding system provided to solve the above problem. In this type of circuit, the vehicle body is connected to the rail 36 via the grounding resistor 23, the grounding brush 14, and the wheel 35, that is, grounded. By doing so, the load current of the train B flowing through the ground brush of the train A can be greatly reduced, and the life of the ground brush 14 can be extended.

  FIG. 9 shows a schematic configuration of a motor drive circuit for a vehicle adopting the grounding system as shown in FIG. 8, where (a) is a circuit diagram base and (b) is a vehicle body outfitting base.

  A main converter (hereinafter referred to as “main converter”) 15 that uses single-phase AC power from the AC overhead line 10 as a power source is driven by three-phase AC on the load side (for example: Induction motor, synchronous motor) 24 is connected. The vehicle body 27 is grounded (connected to the rail side) via the grounding resistor 23.

  In such a drive circuit system, the PWM voltage generated by the main converter 15 generates a high-frequency common current Icom via a floating capacitor component between the winding portion 24a in the main motor and the main motor case 24b. It flows through the neutral point grounding part 21 of the main converter 15. The path of the high-frequency common current Icom is the main motor case 24b, the ground wire 31, the grounding resistor 23, the vehicle body 27, and the main converter neutral point grounding portion 21. In some cases, as shown by a dotted line in the lower right of FIG. 9A, it is conceivable that the main motor case 24b flows into the vehicle body. At this time, since the high-frequency common current path and the vehicle body are in contact with each other at multiple points, the high-frequency common current flows via the vehicle body 27. As a result, a potential fluctuation or the like in the vehicle body is generated, thereby causing an influence of noise on electronic devices such as the vehicle control device and the power conversion device control device. That is, when a current flows through the vehicle body, a difference occurs in the GND level of each electronic device, and the S / N ratio of the signal deteriorates. In addition, when a current flows through the vehicle body, it is considered that noise is mixed into the signal, and further noise is radiated to the ground element such as ATC or ATS outside the vehicle body.

  Accordingly, the present invention provides an electric vehicle that suppresses a high-frequency common current generated through a floating capacitor component between the main motor inner winding portion and the main motor case from flowing through the vehicle body by the PWM voltage generated by the main converter. An object of the present invention is to provide a circuit configuration.

In order to solve the above-described problem, a circuit configuration of an electric vehicle according to an embodiment of the present invention includes: an electric motor that rotationally drives a wheel; and single-phase AC power supplied from an overhead wire is converted into three-phase AC power, A main converter having an electrical neutral point, a three-phase AC output line for electrically connecting the motor and the main converter, and a motor connected to a wheel via a ground brush. A ground wire connected to the case, and a ground resistor connected between the ground wire and the vehicle body, and the electrical neutral point of the main converter and the ground resistor are common. The three-phase AC output line and the ground line are provided in close contact with each other.

  Inflow of the high-frequency common current generated through the floating capacitor component between the main motor inner winding portion and the main motor frame is suppressed to the vehicle body. As a result, the vehicle body potential fluctuation is suppressed, and the radiation noise of the high-frequency common current can be suppressed.

The figure which shows schematic structure of the motor drive circuit for vehicles which concerns on 1st Example of this invention. The figure which shows schematic structure of the motor drive circuit for vehicles which concerns on 2nd Example of this invention. The figure which shows schematic structure of the motor drive circuit for vehicles which concerns on 3rd Example of this invention. The figure which shows the magnetic body core which a power supply earth line and a three-phase alternating current output line penetrate. The figure which shows schematic structure of the motor drive circuit for vehicles which concerns on 4th Example of this invention. The figure which shows schematic structure of the motor drive circuit for vehicles which concerns on 5th Example of this invention. The figure which shows schematic structure of the main electric circuit for vehicles of the conventional vehicle body earth system. The figure which shows schematic structure of the main electrical circuit for vehicles of the earthing system which connected resistance between earth | ground and a vehicle body. The figure which shows schematic structure of the main motor drive circuit of the vehicle which employ | adopted the earth system like FIG.

  In the following, an inductive failure measure for a vehicle motor drive circuit according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an outline of a motor drive circuit for a vehicle according to a first embodiment of the present invention, where (a) is a circuit diagram base and (b) is a vehicle body outfitting base.

  Electric power is supplied from the substation to the primary side of the main transformer 13 via the overhead line 10, the pantograph 11, and the circuit breaker VCB 12. The current flowing through the main transformer 13 returns to the substation via the ground brush 14, the wheel 35, and the rail 36. A main converter 15 is connected to the secondary side of the main transformer 13.

  Main converter 15 includes a PWM converter 16 and a PWM inverter 17. The converter 16 converts AC power provided from the secondary side of the main transformer 13 into DC power using the PWM method. The output DC voltage of the converter 16 is applied to the series circuit of the filter capacitors 41 and 42 and is supplied to the inverter 17. The inverter 17 converts the input DC voltage into a VVVF three-phase AC voltage by the PWM method, and drives the main motor 24.

  The case 24 b of the main motor 24 is grounded to the rail 36 through the ground wire 31, the ground brush 14, and the wheels 35. A grounding resistor 23 is connected between the ground wire 31 and the vehicle body 27.

  A neutral point (a connection point of the capacitors 41 and 42) 18 output from the converter 16 is connected to one terminal 22 a of the ground switch 22 through the ground circuit 19. The ground circuit 19 includes a capacitor 19a, a relay coil 19b, and a relay contact (not shown). The ground circuit 19 is a ground fault detection relay, which is in an ON state during normal operation, and when a ground fault occurs, a current of a predetermined current value or more flows through the coil 19b and enters an OFF state.

  The other terminal 22 b of the ground switch 22 is connected to the vehicle body 27 via the wiring 44 and the connection point 30 of the vehicle body 27. The ground switch 22 is a pressure test switch, and is in an OFF state during a pressure test between the main converter 15 and the vehicle body, and in an ON state during normal operation.

  As described above, in the first embodiment, the electrical neutral point 18 of the main converter 15 is connected to the connection point 30 during normal operation. The ground resistor 23 is also connected to the connection point 30. That is, the electrical neutral point 18 and the grounding resistor 23 are connected to the vehicle body 27 at the common connection point 30. As a result, the high-frequency common current Icom generated via the floating capacitor component 26 between the winding portion 24a in the main motor and the main motor case 24b flows back through the main converter 15 and the main motor 24 without flowing through the vehicle body 27. . Thus, by connecting the electrical neutral point of the main converter 15 and the grounding resistor 23 to the vehicle body 27 via the common connection point 30, the high-frequency common current Icom flowing through the vehicle body can be significantly suppressed. As a result, noise generation for each electronic device can be suppressed.

  FIG. 2 is a diagram showing a configuration of a vehicle motor drive circuit according to a second embodiment of the present invention.

  The circuit configuration of the second embodiment is the same as the conventional configuration of FIG. 9, but the three-phase AC output line 25 and the ground wire 31 connected to the ground brush 14 are arranged in close contact with each other. That is, in the second embodiment, the three-phase output line 25 and the ground wire 31 to the main motor 24 are wired in a bundle. Thus, the radiation noise to the exterior is suppressed by sticking the three-phase alternating current output line 25 and the earth line 31 closely.

  FIG. 3 is a diagram showing the configuration of a vehicle motor drive circuit according to a third embodiment of the present invention.

  The circuit configuration of the third embodiment is the same as the conventional configuration of FIG. 9, but a magnetic core 32 is provided for the power supply ground line 31 and the three-phase AC output line 25 connected to the ground brush 14. FIG. 4 is a diagram showing this state. As shown in FIG. 4, in this embodiment, the magnetic core 32 is provided so that the power supply ground line 31 and the three-phase AC output line 25 penetrate. Since the magnetic core 32 acts as an inductance component with respect to the high frequency current, the high frequency common current Icom flowing out from the main motor frame is suppressed.

  FIG. 5 is a diagram showing the configuration of a vehicle motor drive circuit according to a fourth embodiment of the present invention.

  In the fourth embodiment, a magnetic core 32 is provided for the neutral point ground line 21 a and the three-phase AC output line 25 wired in the main converter 15. For example, when the magnetic core 32 cannot be provided in the body mounted state as in the third embodiment of FIG. 3, the magnetic core is arranged in the main converter as shown in FIG. The operation and effect of the fourth embodiment is that the high frequency common current Icom is suppressed by the magnetic core 32 as in the third embodiment of FIG. Further, as shown in FIG. 5, the main conversion device 15 configured by passing the neutral point ground wire 21 a and the three-phase AC output line 25 through the magnetic core 32 may be provided as a product.

  FIG. 6 is a diagram showing the configuration of a vehicle motor drive circuit according to a fifth embodiment of the present invention.

  As shown in FIG. 6B, the vehicle A according to the fifth embodiment has a main conversion device 45 that provides the motor drive VVVF three-phase power to the vehicle B that does not have the main conversion device. That is, in the fifth embodiment, the vehicle A on which the main conversion device 45 is mounted is different from the vehicle B on which the electric motor 24B driven by the main conversion device 45 is mounted. In the vehicle A, the three-phase AC line 25 and the power supply ground line 31 for the vehicle B on which the electric motor 24B to be driven is mounted are configured to penetrate the magnetic core 32. As a result, the high-frequency common current from the vehicle B on which the main conversion device is not mounted to the vehicle A on which the main conversion device is mounted is suppressed.

The above description is an embodiment of the present invention, and does not limit the apparatus and method of the present invention, and various modifications can be easily implemented.
The invention described in the scope of the claims at the beginning of the present application is added below.
[1]
An electric motor for rotating the wheels;
A main converter that converts single-phase AC power supplied from an overhead wire into three-phase AC power and drives the motor;
A ground wire connected to the wheel via a grounding brush and connected to the case of the motor;
A grounding resistor connected between the ground wire and the vehicle body,
The electric neutral circuit of the main converter and the grounding resistor are connected to the vehicle body at a common connection point.
[2]
An electric motor for rotating the wheels;
A main converter that converts single-phase AC power supplied from an overhead wire into three-phase AC power and drives the motor;
A ground wire connected to the wheel via a grounding brush and connected to the case of the motor;
A grounding resistor connected between the ground wire and the vehicle body,
A circuit configuration of an electric vehicle, wherein the three-phase AC output line of the main converter and the ground wire are provided in close contact with each other.
[3]
An electric motor for rotating the wheels;
A main converter that converts single-phase AC power supplied from an overhead wire into three-phase AC power and drives an electric motor;
A ground wire connected to the wheel via a grounding brush and connected to the case of the motor;
A grounding resistor connected between the ground wire and the vehicle body;
A magnetic core through which the three-phase AC output line of the main converter and the ground wire penetrate,
A circuit configuration of an electric vehicle comprising:
[4]
An electric motor for rotating the wheels;
A main converter that converts single-phase AC power supplied from an overhead line into three-phase AC power and drives an electric motor of a vehicle connected to the host vehicle;
A ground wire connected to the wheel via a ground brush;
A grounding resistor connected between the ground wire and the vehicle body;
A magnetic core through which the three-phase AC output line of the main converter and the ground wire penetrate,
A circuit configuration of an electric vehicle comprising:
[5]
A converter that converts single-phase AC power into DC power;
An inverter that converts the DC power converted by the converter into a three-phase AC for a vehicle motor;
A magnetic core through which the three-phase AC output line of the inverter and the electric neutral point grounding line of the DC power penetrate,
A circuit configuration of an electric vehicle comprising:

  DESCRIPTION OF SYMBOLS 10 ... Overhead wire, 11 ... Pantograph, 12 ... Circuit breaker, 13 ... Main transformer, 14 ... Grounding brush, 15 ... Main converter, 23 ... Grounding resistor, 24 ... Main motor, 27 ... Car body, 31 ... Ground wire, 32: Magnetic core.

Claims (9)

An electric motor for rotating the wheels;
A main converter that converts single-phase AC power supplied from an overhead wire into three-phase AC power, drives the motor, and has an electrical neutral point;
A three-phase AC output line for electrically connecting the electric motor and the main converter;
A ground wire connected to the wheel via a grounding brush and connected to the case of the motor;
A grounding resistor connected between the ground wire and the vehicle body,
The electrical neutral point of the main converter and the grounding resistor are connected to the vehicle body at a common connection point,
The drive circuit for an electric vehicle, wherein the three-phase AC output line and the ground line are provided in close contact with each other. While not detecting a ground fault, the main converter and the connection point are electrically connected, and when a ground fault is detected, a ground circuit that releases the electrical connection between the main converter and the connection point;
A grounding switch provided between the main converter and the connection point;
A grounding resistor connecting the connection point and the motor case;
The electric vehicle drive circuit according to claim 1, further comprising: The ground circuit includes a capacitor and a relay coil.
The drive circuit for an electric vehicle according to claim 2. The relay coil of the ground circuit detects a ground fault when a predetermined current value or more flows.
The electric vehicle drive circuit according to claim 3. One end of the ground switch is electrically connected to the case of the vehicle body via the connection point.
The drive circuit for an electric vehicle according to any one of claims 2 to 4. The ground switch electrically opens between the main converter and the vehicle body during a pressure test.
The drive circuit for an electric vehicle according to any one of claims 2 to 5. An electric motor for rotating the wheels;
A main converter that converts single-phase AC power supplied from an overhead wire into three-phase AC power, drives a motor of a vehicle connected to the host vehicle, and has an electrical neutral point;
A ground wire connected to a case of a motor of a vehicle connected to the vehicle wheel and connected to the vehicle wheel via a ground brush;
A grounding resistor connected between the ground wire and the vehicle body;
A three-phase AC output line for connecting the main converter and the electric motor, and the magnetic core, wherein a ground wire through both
Comprising
An electric vehicle driving circuit, wherein the electrical neutral point and the grounding resistor are connected to the vehicle body at a common connection point. A main converter that converts electric power supplied from an overhead wire into electric power for driving, and has an electrical neutral point;
A driving power output line for outputting the electric power converted by the main converter to an electric motor;
A ground wire connected to the wheel via a grounding brush and connected to the case of the motor;
A grounding resistor connected between the ground wire and the vehicle body;
Comprising
The electrical neutral point of the main converter and the grounding resistor are connected to the vehicle body at a common connection point,
The power conversion device for a vehicle, wherein the drive power output line and the ground wire are provided in close contact with each other. The main converter converts the power supplied from the overhead wire into three-phase AC power.
The vehicle power converter according to claim 8.

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