HK1178496B - Vehicle control system - Google Patents

Description

Vehicle control system

Technical Field

Embodiments described herein relate generally to vehicle control systems.

Background

Generally, an induction motor is widely used as a driving system of a railway vehicle. However, drive systems with permanent magnet synchronous motors have recently become popular for energy conservation reasons. In a permanent magnet synchronous motor, magnets embedded within a rotor generate a magnetic field and generate an electric current in the rotor. Unlike induction motors, permanent magnet synchronous motors have no current loss in the rotor and also do not cause heat generation due to current loss. Therefore, the drive system with the permanent magnet synchronous motor is more efficient than the drive system with the induction motor.

On the other hand, there are negative effects of embedding magnets in the rotor of a permanent magnet synchronous motor. One of the negative effects is induced voltage. The induced voltage is generated by an embedded magnet and increases commensurately with the rotational speed. During high speed rotation, the induced voltage may exceed the DC voltage of the inverter circuit controlling the device. When the induced voltage exceeds a DC voltage of the inverter circuit, a regeneration operation is automatically started. Therefore, even when the railway vehicle runs by inertia, it is necessary to intentionally conduct a current to lower the induced voltage in order to reduce the magnetic flux.

Other problems occur when the motor and the inverter circuit for the motor are provided on different vehicles (vehicles). In such a case, interconnection between the car with the motor and the car with the inverter is then necessary. A short circuit may occur on the interconnect. When a short-circuit accident or a ground fault accident occurs between the inverter circuit and the permanent magnet synchronous motor, regeneration is hindered and the magnetic flux caused by the induced voltage interferes with the normal operation of the permanent magnet synchronous motor. These problems do not occur in the induction motor.

Disclosure of Invention

In order to achieve the above object, a vehicle control system according to the present disclosure includes: an inverter circuit provided in the first vehicle module, a permanent magnet synchronous motor provided in the second vehicle module, and a cross-over (crossover) provided between the second vehicle module and a vehicle module adjacent to the second vehicle module for electrically connecting the inverter circuit and the permanent magnet synchronous motor. The system may also include at least one current sensor mounted between the inverter circuit and the permanent magnet synchronous motor. A contactor may also be connected between the bridge and the permanent magnet synchronous motor, which may conduct or cut off a current (electric) between the inverter circuit and the permanent magnet synchronous motor. The system may further include a control unit connected to the contactor and the current sensor. The control unit may detect an abnormality of the current by using information from the current sensor, and open the contactor if the abnormality is detected. The current anomaly may be one from the group consisting of: two-phase short circuit, three-phase short circuit and ground fault accident. The system may further include three current wires disposed between the inverter circuit and the permanent magnet synchronous motor, two of the three wires including a current sensor. Detecting a two-phase short circuit may include determining respective phases of currents on the line based on information provided by the sensors and opening the contactor if the currents are not within a predetermined phase difference from each other, wherein the predetermined phase difference is 120 degrees. Detecting a three-phase short circuit may include determining current values of the three current lines and opening the contactor when the current values exceed a predetermined level. Detecting a ground fault may include determining a current between the inverter circuit and ground and opening the contactor when the current is greater than a predetermined current.

A method is disclosed, comprising: providing current from an inverter disposed in a first vehicle module to a permanent magnet synchronous motor disposed in a second vehicle module; electrically connecting the inverter to the permanent magnet synchronous motor with a crossover disposed between the second vehicle module and a vehicle module adjacent to the second vehicle module; measuring the current supplied to the permanent magnet synchronous motor; the current supplied to the permanent magnet synchronous motor is controlled by detecting whether there is an abnormality associated with supplying the current to the permanent magnet synchronous motor, and opening a contactor provided between the crossover and the permanent magnet synchronous motor if the abnormality is detected. The exception may be one from the group consisting of: two-phase short circuit, three-phase short circuit and ground fault accident. The crossover may comprise three current lines, two of which comprise current sensors. Detecting a two-phase short circuit may include determining whether a phase difference between current phases on at least two of the three current lines differs by a predetermined phase difference, e.g., 120 degrees. Detecting the three-phase circuit includes determining whether at least one current value of the three current lines exceeds a predetermined level. Detecting a ground fault may include determining whether a current between the inverter and ground exceeds a predetermined current.

Additional systems may include: an inverter circuit that is provided in the first vehicle module and controls electric power supplied from the overhead wire so as to be able to drive the electric power; a permanent magnet synchronous motor provided in a second vehicle module and driven by electric power from the inverter circuit as driving force; a crossover provided between the second vehicle module and a vehicle module adjacent to the second vehicle module for electrically connecting the inverter circuit and the permanent magnet synchronous motor; an AC current detection sensor installed between the inverter circuit and the bridge to detect a current; a contactor connected between the bridge and the permanent magnet synchronous motor so as to be capable of performing electrical disconnection and energization operations; a DC current sensor between the inverter circuit and ground; and a control unit connected to the contactor, the AC current sensor, and the DC current sensor. The control unit may determine an abnormality, such as a ground fault accident and a short-circuit accident, generated at the bridge in the drive system. The determination may be based on a current value detected from at least one of the AC current sensor and the DC current sensor. When an abnormality is sensed, the control unit outputs a disconnection instruction to the contactor.

Drawings

Fig. 1 is a block diagram of a vehicle control system according to a first embodiment.

Fig. 2A, 2B, and 2C are flow diagrams depicting a method of detecting system anomalies in accordance with aspects of the present disclosure.

FIG. 3 is a block diagram of a vehicle control system according to aspects of the present disclosure.

Detailed Description

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. The structure of a vehicle control system according to a first embodiment of the present disclosure will be described with reference to fig. 1.

Referring to fig. 1, the vehicle control system of the first embodiment may include: the pantograph 1, the inverter circuit 2, the first current sensor 3a, the second current sensor 3b, the U-phase circuit 4a, the V-phase circuit 4b, the W-phase circuit 4c, the contactor 5, the permanent magnet synchronous motor 6, the third current sensor 7, the ground 8, the control unit 9, the input current calculation unit 9a, the detection unit 9b, the contactor controller 9c, the U-phase crossover 10a, the V-phase crossover 10b, and the W-phase crossover 10 c.

The pantograph 1 and the ground 8 may be connected to the inverter circuit 2 on the DC side. The third current sensor 7 may be connected between the inverter circuit 2 and ground 8. On the AC side of the inverter circuit 2, which is opposite to the DC side, the inverter circuit 2 and the permanent magnet synchronous motor 6 may be connected through the first current sensor 3a on the U-phase line 4a, the U-phase bridge 10a, and the contactor 5. The inverter circuit 2 and the permanent magnet synchronous motor 6 may be connected through a V-phase crossover 10b on a V-phase line 4b and a contactor 5. The inverter circuit 2 and the permanent magnet synchronous motor 6 may be connected through the second current sensor 3b on the W-phase line 4c, the W-phase bridge 10c, and the contactor 5.

The control unit 9 may be connected to the first current sensor 3a, the second current sensor 3b, the third current sensor 7 and the contactor 5. An input current calculation unit 9a included in the control unit 9 may be connected to the first current sensor 3a, the second current sensor 3b, the third current sensor 7, and the detection unit 9 b. The detection unit 9b may be connected to the input current calculation unit 9a and the contactor controller 9 c. The contactor controller 9c may be connected to the detection unit 9b and the contactor 5.

The function of the embodiment of fig. 1, in accordance with various aspects of the present disclosure, will be described below. The inverter circuit 2 may be supplied with DC power through the pantograph 1. The inverter circuit 2 may convert the input DC power into AC power. The converted AC power may be input to the permanent magnet synchronous motor 6 through the contactor 5, the contactor 5 being normally in an open/closed state. Before reaching the permanent magnet synchronous motor 6, the AC power may be detected by the first current sensor 3a of the U-phase and the second current sensor 3b of the W-phase. The third current sensor 7 may detect a return current of the DC side of the inverter circuit 2.

The currents detected by the first current sensor 3a, the second current sensor 3b, and the third current sensor 7 may be input to the control unit 9. In the control unit 9, the input current calculation unit 9a may calculate the input current levels of the three inputs. Based on the current value calculated in the input current calculation unit 9a, the detection unit 9b can determine whether there is an abnormality in the drive system, such as a contact fault or a ground fault. When the detection unit 9b determines that there is an abnormality, it may send a signal to the contactor controller 9 c. The contactor controller 9c may trigger some or all of the contactors 5 to become open/closed states in response to a signal from the detection unit.

One exemplary embodiment of a control unit, such as control unit 9 in fig. 1, is described below. The exemplary control unit embodiment will be described below with reference to fig. 2. As shown in fig. 2A, the process may start at step S1, and the control unit may receive the current Iu detected by the first current sensor in the U-phase line and the current Iw detected by the second current sensor in the W-phase line at step S2. The input current calculation unit of the control unit may receive the detected currents Iu and Iw and calculate phases Iu ', Iv ', and Iw ', which correspond to the phases of the U-phase line, the V-phase line, and the W-phase line, respectively. The phase Iv ' may be calculated based on the currents Iu and Iw and the phases Iu ' and Iw '. Subsequently, said phases Iu ', Iv ' and Iw ' may be input to a detection unit, e.g. the detection unit 9b from fig. 1. In step S3, the detection unit may compare the phases of some or all of the currents Iu, Iv, and Iw. For example, the detection unit may determine whether the phase Iw 'lags the phase Iu' by a predetermined phase, e.g., 240 °. If the phase Iw 'lags the phase Iu' by 240 deg., the detection unit may determine that the system is operating normally, and may repeatedly perform steps S2-S3. The detection unit may also confirm other predetermined phase deviations between Iu ', Iv ' and Iw ', e.g. whether the phase Iv ' lags the phase Iu ' by 120 ° or whether the phase Iw ' lags the phase Iv ' by 120 °.

On the other hand, if the phase Iw 'does not lag the phase Iu' by 240 °, or there is another phase deviation, the detection circuit may determine that there is an abnormality at step S4. For example, one exemplary abnormality indicated by the phase deviation may be a two-phase short circuit generated by the wirings in the U-phase bridge 10a and the V-phase bridge 10 b. When a two-phase short is confirmed, the detection unit may send a signal to the contactor controller. When the contactor controller receives the signal, the contactor controller may open the contactor at step S5.

As shown in fig. 2B, certain embodiments of the control unit may detect current deviations in addition to phase deviations. At step S12, a control unit, such as the control unit 9 of fig. 1, may receive a current Iu detected by a first current sensor (e.g., the current sensor 3a in the U-phase line), and a current Iw detected by a second current sensor (e.g., the second current sensor 3b in the W-phase line). Using the detected current Iu and the detected current Iw, an input current calculation unit (e.g., input current calculation unit 9a) of the control unit may calculate current values of the current Iu, the current Iv, and the current Iw. The current values of the current Iu, the current Iv and the current Iw may then be input to a detection unit, such as the detection unit 9b of fig. 1. In step S13, the detection unit may determine whether the calculated current values Iu and Iw exceed a predetermined value α. For example, the predetermined value may be a fraction of the current difference between currents Iu and Iw, or the total current difference. If the calculated current values Iu and Iw do not exceed the predetermined value α, there is no system abnormality, and the control unit may repeatedly perform steps S11 to S13.

On the other hand, if the calculated current values of the current Iu and the current Iw exceed the predetermined value α, the detection unit may determine that there is an abnormality in the system at step S14. For example, in fig. 2B, the fact that the currents Iu and Iw exceed the predetermined value α may indicate that the abnormality is a three-phase short circuit. A three-phase short circuit may be caused by a short circuit in the jumper wirings, for example, a plurality of wirings from the U-phase jumper 10a, the V-phase jumper 10b, and the W-phase jumper 10c of fig. 1. Therefore, a three-phase short circuit was confirmed. When a three-phase short circuit is confirmed, the detection unit may input a signal to the contactor controller. In step S15, the contactor controller may receive the signal from the detection unit and trigger a contactor, such as contactor 5 in fig. 1, to open.

Certain embodiments of the control unit may also detect ground fault incidents. Fig. 2C illustrates an exemplary method for detecting a ground fault incident. In step S22, the control unit may receive a current IAC detected by a third current sensor, e.g. the third current sensor 7 from fig. 1, on the DC return side of the inverter circuit, e.g. the inverter circuit 2. The current IAC may be a short-circuit current of the system. The detection unit within the control unit may receive the detected current IAC through an input current calculation unit (e.g., the input current calculation unit 9a), or the detection unit may directly receive the detected current IAC. In step S23, the detection unit may determine whether current IAC exceeds a predetermined value β, which may be selected as a threshold value based on at least one abnormal situation. If the current IAC does not exceed the predetermined value β, no ground fault accident occurs, and the control unit may repeatedly perform steps S21-S23.

On the other hand, if the detected current IAC exceeds the predetermined value β, the detection unit may determine that there is an abnormality, such as a ground fault accident, at step S24. When a short circuit occurs between two crossover wirings, such as the wirings in the U-phase crossover 10a, the V-phase crossover 10b, and the W-phase crossover 10c from fig. 1, a ground fault accident may occur. When the ground fault accident is confirmed, the detection unit may input a signal to the contactor controller. At step S25, the contactor controller may receive the signal and trigger the contactor to open.

An exemplary embodiment of a vehicle control system, such as the vehicle control system of FIG. 1, is shown in FIG. 3. In fig. 3, the inverter circuit 2 is provided in the first module 11, and the permanent magnet synchronous motor 6 and the contactor 5 are provided in the second module 12.

A fault circuit may occur between the modules 11 and 12. For example, a fault circuit (e.g., a ground fault) may occur when the U-phase jumper 10a and the V-phase jumper 10b are connected. The connection between the spans may cause the current output by the permanent magnet synchronous motor 6 to return to the permanent magnet synchronous motor 6. For example, when a short circuit is generated in the U-phase bridge 10a and the V-phase bridge 10b, the current may continue to be conducted through the permanent magnet synchronous motor 6, the inverter circuit 2, and the like without being absorbed (recodesigned) or dissipated. This may overload the motor and the circuit and hinder the running of the railway vehicle. However, when the contactor 5 is opened, the current output from the permanent magnet synchronous motor 6 will stop. In case the contactor 5 is open, said current is prevented from conducting through the device comprising the permanent magnet synchronous motor 6.

According to the above embodiment of the vehicle control system, the vehicle control system is advantageous in that: it can protect the inverter circuit even in the event of a contact fault or ground fault between different conductors.

While specific embodiments of the vehicle control system have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the present disclosure. Indeed, the novel systems described herein may be presented in a variety of other forms; further, various omissions, substitutions and changes in the form of the system described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the spirit and scope of the disclosure.

Claims (20)

1. A vehicle control system comprising:

an inverter circuit provided in the first vehicle module;

a permanent magnet synchronous motor provided in the second vehicle module;

a crossover provided between the second vehicle module and a vehicle module adjacent to the second vehicle module for electrically connecting the inverter circuit and the permanent magnet synchronous motor;

a current sensor connected between the inverter circuit and the permanent magnet synchronous motor;

a contactor connected between the bridge and the permanent magnet synchronous motor, the contactor being configured to conduct or cut off a current between the inverter circuit and the permanent magnet synchronous motor; and

a control unit connected to the contactor and the current sensor, the control unit for detecting an abnormality using information from the current sensor and opening the contactor if an abnormality is detected.

2. The system of claim 1, wherein the anomaly is one from the group consisting of: two-phase short circuit, three-phase short circuit and ground fault accident.

3. The system of claim 1, further comprising: three current lines provided between the inverter circuit and the permanent magnet synchronous motor, two of the three lines including a current sensor.

4. The system of claim 3, wherein the control unit is connected to the current sensor and is configured to open the contactor when a two-phase short circuit is detected by:

determining respective phases of currents on the lines based on information provided by the sensors; and is

Opening the contactor if the currents are not within a predetermined phase difference from each other.

5. The system of claim 4, wherein the predetermined phase difference is 120 degrees.

6. The system of claim 3, wherein the control unit is connected to the current sensor and is configured to open the contactor when a three-phase short circuit is detected by:

determining a current value of the line; and is

The contactor is opened when the current value exceeds a predetermined level.

7. The system of claim 1, further comprising: a current sensor connected between the inverter circuit and ground, the sensor in communication with the control unit, wherein the control unit is configured to open the contactor upon detection of a ground fault by:

determining a current between the inverter circuit and ground; and is

And when the current is larger than the preset current, opening the contactor.

8. A method for a vehicle control system, comprising:

providing current from an inverter disposed in a first vehicle module to a permanent magnet synchronous motor disposed in a second vehicle module;

electrically connecting the inverter to the permanent magnet synchronous motor with a crossover disposed between the second vehicle module and a vehicle module adjacent to the second vehicle module;

measuring the current provided to the permanent magnet synchronous motor; and

controlling the current provided to the permanent magnet synchronous motor by:

detecting whether there is an abnormality associated with supplying current to the permanent magnet synchronous motor; and is

If an abnormality is detected, a contactor provided between the bridge and the permanent magnet synchronous motor is opened.

9. The method of claim 8, wherein the anomaly is one from the group consisting of: two-phase short circuit, three-phase short circuit and ground fault accident.

10. The method of claim 9, wherein the crossover comprises three current lines, two of the three lines comprising a current sensor.

11. The method of claim 10, wherein detecting the two-phase short circuit comprises determining whether a phase difference between phases of currents on at least two of the three current lines differs by a predetermined phase difference.

12. The method of claim 11, wherein the predetermined phase difference is 120 degrees.

13. The method of claim 10, wherein detecting the three-phase short circuit comprises determining whether at least one current value of the three current lines exceeds a predetermined level.

14. The method of claim 10, wherein detecting the ground fault comprises determining whether a current between the inverter and ground exceeds a predetermined current.

15. A vehicle control system comprising:

an inverter circuit that is provided in the first vehicle module and receives electric power from the overhead wire;

a permanent magnet synchronous motor provided in the second vehicle module and driven by electric power supplied from the inverter circuit;

a crossover provided between the second vehicle module and a vehicle module adjacent to the second vehicle module for electrically connecting the inverter circuit and the permanent magnet synchronous motor;

an AC current detection sensor mounted between the inverter circuit and the bridge section;

a contactor connected between the bridge and the permanent magnet synchronous motor;

a DC current detection sensor connected between the inverter circuit and ground; and

a control unit connected to the contactor, the AC current sensor and the DC current sensor, wherein

The control unit senses an abnormality based on a current value from at least one of the AC current sensor and the DC current sensor, and outputs an opening instruction to the contactor.

16. The system of claim 15, wherein the bridge comprises a plurality of flexible wires and an anomaly occurs when at least two of the plurality of flexible wires are shorted.

17. The system of claim 15, wherein the control unit comprises an input current calculation unit, a detection unit, and a contactor controller.

18. The system of claim 17, wherein the AC current detection sensor and the DC current detection sensor are connected to the input current calculation unit.

19. The system of claim 18, wherein the detection unit receives at least one current value calculated on the input current calculation unit and determines whether an anomaly exists based at least in part on the current value.

20. The system of claim 19, wherein if an anomaly exists, the detection unit sends a signal to the contactor controller, and the contactor controller triggers the contactor to open the circuit from the inverter circuit to the permanent magnet synchronous motor.