WO2017185715A1

WO2017185715A1 - Urban rail transit traction system

Info

Publication number: WO2017185715A1
Application number: PCT/CN2016/105655
Authority: WO
Inventors: 车向中; 郭建斌; 姜涛; 马晨普
Original assignee: 中车大连电力牵引研发中心有限公司
Priority date: 2016-04-28
Filing date: 2016-11-14
Publication date: 2017-11-02
Also published as: CN105904987A

Abstract

An urban rail transit traction system, comprising a control unit (1), an energy storage unit (2), a traction converter unit (3), and a traction motor (4). The traction converter unit (3) is connected between two direct-current buses of an external power supply unit (5); the energy storage unit (2) is separately connected with the direct-current buses of the external power supply unit (5) and the traction converter unit (3); the energy storage unit (2) is used for storing electric energy provided by the external power supply unit (5); the traction converter unit (3) is individually connected with the control unit (1) and the traction motor (4); the control unit (1) is used for controlling the traction converter unit (3) to charge the energy storage unit (2) for energy storing and/or discharge the energy storage unit (2) for energy releasing, to convert the direct-current electric energy stored in the energy storage unit (2) to alternating-current electric energy, and to output the alternating-current electric energy to the traction motor (4) to drive a train to run. In the urban rail transit traction system, the energy storage unit (2) is charged when the train approaches a station and parks and supplies power to the train using its stored electric energy during the running of the train, without using uninterrupted contact line for powering the train, thereby reducing the project costs, and also reducing the potential safety hazards caused by the uninterrupted contact line.

Description

Urban rail transit traction system

Technical field

The invention relates to the field of power traction technology, in particular to an urban rail transit traction system.

Background technique

Urban rail transit mainly refers to urban subways, urban fast rail, light rail, and trams. The basic function of the traction system of urban rail transit is to provide power for the operation of urban rail trains.

In the prior art, urban rail transit generally adopts a continuous power receiving mode, and by using an overhead contact network or a ground power supply rail, the train is provided with uninterrupted electric energy as the train operates. Correspondingly, the traction system of urban rail transit generally adopts the main circuit topology of “inverter + traction motor”. The function of the inverter is to convert the electric energy from the overhead contact network or the ground supply rail into electric energy suitable for the traction motor. The role of the traction motor is to convert electrical energy into mechanical energy to drive the operation of the urban rail train.

However, the prior art traction system needs to supply power from the uninterrupted DC power of the power grid. Therefore, the power receiving system must adopt a contact network or a power supply rail, and the use of an uninterrupted contact network or a power supply rail undoubtedly increases the engineering. The cost also has certain security risks.

Summary of the invention

The object of the present invention is to provide an urban rail transit traction system, which solves the problem that the prior art method of erecting the power supply contact network has certain safety problems, increases the construction cost, and has certain safety hazards.

The invention provides an urban rail transit traction system, comprising:

Control unit, energy storage unit, traction converter unit and traction motor;

The traction converter unit is connected between the two DC busbars of the external power supply unit, and the energy storage unit is respectively connected to the DC bus and the traction converter unit of the external power supply unit;

The energy storage unit is configured to store electrical energy provided by an external power supply unit;

The traction converter unit is respectively connected to the control unit and the traction motor, and the control unit is configured to control the traction converter unit to perform charging and energy storage and/or discharge release on the energy storage unit; The DC power stored in the unit can be converted into AC power and output to the traction motor. Drive the train to run.

The urban rail transit traction system provided by the invention can be charged by the energy storage unit when the train stops at the stop, and the electric energy stored by the energy storage unit is used to power the train during the running of the train, thereby eliminating the need for an uninterrupted contact network for the train. For power supply, only a small section of external power supply unit is installed on the ground of the station, which reduces the construction cost and reduces the safety hazard caused by the uninterrupted contact network.

DRAWINGS

1 is a schematic structural view of an urban rail transit traction system according to Embodiment 1 of the present invention;

2 is a schematic structural diagram of an urban rail transit traction system according to Embodiment 2 of the present invention;

FIG. 3 is a schematic structural diagram of still another urban rail transit traction system according to Embodiment 2 of the present invention.

Reference mark:

1-control unit; 2- energy storage unit;

3-traction converter unit; 4-traction motor;

5- external power supply unit; 6-switch switching unit;

611-first switch; 621-second switch;

622-current limiting resistor; 31-charge and discharge electronic unit;

32-inverter subunit; 21- freewheeling reactor;

7-High speed circuit breaker.

detailed description

Embodiment 1

1 is a schematic structural diagram of an urban rail transit traction system according to Embodiment 1 of the present invention. As shown in FIG. 1 , the urban rail transit traction system provided by this embodiment includes: a control unit 1, an energy storage unit 2, and a traction converter unit. 3 and the traction motor 4, wherein the traction converter unit 3 is connected between the two DC busbars of the external power supply unit 5, and the energy storage unit 2 is connected to the DC bus and the traction converter unit 3 of the external power supply unit 5, respectively, for energy storage. The unit 2 is used for storing the electric energy provided by the external power supply unit 5, and the traction current conversion unit 3 is respectively connected with the control unit 1 and the traction motor 4, and the control unit 1 is used for controlling the traction current conversion unit 3 to charge and store the energy storage unit 2. Can and / or The discharge energy is discharged, and the DC power stored in the storage unit 2 is converted into AC power, and the output to the traction motor 4 drives the train to run.

The traction converter unit 3 includes, but is not limited to, one of a two-level inverter and a three-level inverter. The traction motor 4 can be, but is not limited to, a three-phase asynchronous motor, a permanent magnet synchronous motor, and a linear motor. The energy storage unit 2 can be one of a super capacitor or a battery or a super capacitor and a battery in parallel.

The supercapacitor has the advantages of high energy density and fast charging and discharging speed, so that it can store enough electric energy in a short time for the train stop to stop for traction during train operation.

Specifically, the energy storage unit 2 can perform high current charging in a short time, so that DC power from the external power supply unit can be quickly stored in the super capacitor or super capacitor through the traction converter unit 3 when the train stops. Alternatively, during train operation, the traction converter unit 3 can convert the DC power from the energy storage unit 2 into AC power suitable for the traction motor 4. Further, the traction motor 4 converts the electrical energy into mechanical energy to drive the train.

In the urban rail transit traction system provided by the embodiment, the energy storage unit 2 can be charged when the train stops at the stop, and the electric energy stored by the energy storage unit 2 is used to supply power to the train during the running of the train, thereby eliminating the need for uninterrupted contact. The network supplies power to the train, and only needs to install a small external power supply unit on the ground of the station, which reduces the construction cost and reduces the safety hazard caused by the uninterrupted contact network.

Embodiment 2

On the basis of the above embodiment, as shown in FIG. 1 , the urban rail transit traction system provided by the embodiment further includes: a switch switching unit 6 connected between the external power supply unit 5 and the traction converter unit 3, and the switch switching unit 6 The first switch branch and the second switch branch are connected in parallel, wherein the first switch branch includes a first switch 611, and the second switch branch includes a second switch 621 and a current limiting resistor 622 connected in series. The switch switching unit 6 is also connected to the control unit 1, which is used to control the closing or opening of the first switch 611 and the second switch 621.

Specifically, after the train decelerates into the station, the control unit 1 controls the second switch 621 to be closed, the current limiting resistor 622 performs current limiting charging control, and the control unit 1 also controls the traction converter unit 3 to be in the charging working mode, and the external power supply unit 1 The energy storage unit 2 is powered. Further, the control unit 1 controls the second switch 621 to be turned off, the first switch 611 is closed, and the external power supply unit 1 performs constant voltage charging on the energy storage unit 2.

This embodiment also provides a specific implementation of the traction converter unit 3. 2 is a schematic structural diagram of an urban rail transit traction system according to Embodiment 2 of the present invention. As shown in FIG. 2, the traction converter unit 3 includes: a charging and discharging electronic unit 31 and an inverter subunit 32, wherein the charging and discharging electronic unit 31 is configured to receive an external charging control signal sent by the control unit 1 to step down the voltage output by the external power supply unit 5 according to the external charging control signal, and charge and store the energy storage unit 2.

The charging and discharging electronic unit 31 is further configured to receive the discharge control signal sent by the control unit 1 to boost the DC voltage output from the energy storage unit 2 according to the discharge control signal, perform discharge discharge on the energy storage unit 2, and charge and discharge the electronic unit. 31 is also used to output the boosted DC voltage to the inverter subunit 32.

It should be noted that when the charging and discharging electronic unit 31 receives the external charging control signal and the discharging control signal, it may be that only one of the signals is received, that is, only the charging energy storage or the discharging energy is performed on the energy storage unit 2. Of course, the page of the charging and discharging electronic unit 31 can receive two kinds of signals, that is, the energy storage unit 2 can also discharge discharge energy while charging and storing energy.

The inverter sub-unit 32 is configured to receive the traction control signal sent by the control unit 1 to convert the boosted DC voltage outputted by the charging and discharging electronic unit 32 into an AC voltage according to the traction control signal to the traction motor 4 to drive the traction motor. 4.

The inverter sub-unit 32 is further configured to receive an electric brake recovery signal sent by the control unit 1 to convert the AC voltage regenerated by the traction motor during braking into a DC voltage output to the charging and discharging electronic unit 31 according to the electric brake recovery signal.

The charging and discharging electronic unit 31 is configured to receive an electric brake charging signal sent by the control unit 1 to perform a step-down output of the DC voltage outputted by the inverter subunit 32 to the energy storage unit 2 according to the electric brake charging signal to store energy Unit 2 performs charging and energy storage.

Specifically, in this embodiment, the working states of the traction system in three modes: the inbound charging mode, the traction running mode, and the braking deceleration mode of the train are described in detail.

Inbound charging mode: After the train enters the station, the control unit 1 controls the second switch 621 to be closed, the current limiting resistor 622 performs current limiting charging control, and the control unit 1 also controls the charging and discharging electronic unit 31 to be in the charging working mode, that is, charging and discharging the electronic The unit 31 receives the external charging control signal sent by the control unit 1, and the charging and discharging electronic unit 31 stores the electric energy in the energy storage unit 2 by performing PWM control on the voltage output from the external power supply unit 5, and the energy storage unit 2 is in the charging. Enter In one step, the control unit 1 controls the second switch 621 to be turned off, the first switch 611 is closed, and the external power supply unit 5 performs constant voltage charging on the energy storage unit 2.

Traction operation mode: after the train is charged, the train starts to enter the traction operation mode, and the charging and discharging electronic unit 31 receives the discharge control signal sent by the control unit 1, and the charging and discharging electronic unit 31 stores the electric energy stored in the energy storage device 2 according to the discharge control signal. After performing PWM control boosting, the power of the energy storage unit 2 is released to the DC bus of the inverter subunit 32, and on the other hand, the control inverter unit 32 receives the traction control signal sent by the control unit 1, and the DC bus is derived from the DC bus. The DC power of the energy storage unit 2 is PWM-controlled to be converted into AC power suitable for driving the traction motor 4, and the traction motor 4 completes the conversion of electrical energy to mechanical energy, thereby driving the train traction operation.

Brake deceleration mode: When the train brake decelerates, the traction motor 4 can convert mechanical energy into electric energy, and this partially converted electric energy is regenerative electric energy. The inverter subunit 32 receives the electric brake recovery signal sent by the control unit 1 on the one hand, and the inverter subunit 32 converts the regenerative alternating current energy from the traction motor 4 into DC power feedback to the DC according to the electric brake recovery signal. On the busbar, on the other hand, the charging and discharging electronic unit 31 receives the electric brake recovery signal sent by the control unit 1, and the charging and discharging electronic unit 31 performs PWM control on the DC bus, and then regenerates the stored electric energy. In the energy storage unit 2, this partially regenerated electrical energy can be reused in the next traction.

Since the urban rail train is characterized by frequent starting and stopping, the traction converter unit 3 provided in this embodiment can realize the storage of the regenerative electric energy during the braking of the train to the energy storage by controlling the inverter subunit 32 and the charging and discharging electronic unit 31. In the unit 2, the reuse of the regenerative electric energy is realized, and therefore the traction system provided by the present invention has a high energy saving effect.

Optionally, the inverter sub-unit 32 can be a two-level inverter or a three-level inverter composed of a plurality of insulated gate bipolar transistor (IGBT) devices.

FIG. 3 is a schematic structural diagram of still another urban rail transit traction system according to Embodiment 2 of the present invention. As shown in FIG. 3, the charging and discharging electronic unit 31 includes two IGBTs connected in series, and the inverter subunit 32 includes: three parallel connected to each other. Two bridge arms, each of which includes two IGBTs connected in series.

The traction converter unit 3 can be equivalent to a four-bridge arm converter, and the control unit 1 controls the inverter by controlling the on-time of the IGBT in the charging and discharging electronic unit 31, and the switching period. The IGBT on-time in the sub-unit 32, as well as the switching period, etc., can be realized. The direct current output from the energy storage unit 2 is converted into alternating current, and the driving of the drive motor 4 is realized by pulse modulation.

Optionally, one end of the energy storage unit 2 can be connected between the two series connected IGBTs of the charging and discharging electronic unit through the freewheeling reactor 21. The freewheeling reactor 21 can stabilize the DC voltage output from the energy storage unit 2, and can also block high frequency interference caused by the external power supply unit 5.

Further, on the basis of the above embodiment, in order to protect the safety of the circuit, a high-speed circuit breaker 7 can be disposed between the switch switching unit 6 and the external power supply unit 5, so that the traction converter unit 3 can be quickly cut off in the event of a fault. The line between the external power supply unit 5 and the line of the traction converter unit 3 and the energy storage unit 2 is secured.

In addition, a lightning rod may be disposed between the external power supply unit 5 and the high speed circuit breaker 7, and the lightning rod may absorb the induced overvoltage or operate the overvoltage protection circuit.

In the urban rail transit traction system provided by the embodiment, the traction converter unit 3 can be equivalent to a four-bridge arm converter, and the control unit 1 realizes the on-time and switching period of the IGBT in the charging and discharging electronic unit 31. By stepping down or boosting, the DC power output from the energy storage unit 2 can be converted into AC power by controlling the IGBT on-time, the switching period, and the like in the inverter sub-unit 32, thereby driving the driving motor 4.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not limited thereto; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that The technical solutions described in the foregoing embodiments are modified, or the equivalents of the technical features are replaced. The modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

An urban rail transit traction system, comprising: a control unit, an energy storage unit, a traction converter unit and a traction motor;

The traction converter unit is connected between two DC busbars of the external power supply unit;

The energy storage unit is respectively connected to the DC bus and the traction converter unit of the external power supply unit, and the energy storage unit is configured to store the power provided by the external power supply unit;

The traction converter unit is respectively connected to the control unit and the traction motor, and the control unit is configured to control the traction converter unit to perform charging and energy storage and/or discharge release on the energy storage unit, and store the energy. The DC power stored in the unit can be converted into AC power and output to the traction motor to drive the train.
The urban rail transit traction system according to claim 1, wherein a switch switching unit is further connected between the external power supply unit and the traction converter unit, and the switch switching unit comprises: a first parallel connection with each other. a switch branch and a second switch branch, the first switch branch includes a first switch, and the second switch branch includes a second switch and a current limiting resistor connected in series with each other;

The switch switching unit is further connected to the control unit, and the control unit is configured to control closing or opening of the first switch and the second switch.
The urban rail transit traction system according to claim 1, wherein the traction converter unit comprises: a charging and discharging electronic unit and an inverter subunit;

The charging and discharging electronic unit is configured to receive an external charging control signal sent by the control unit, to step down a voltage output by the external power supply unit according to the external charging control signal, and perform charging and energy storage on the energy storage unit;

The charging and discharging electronic unit is further configured to receive a discharge control signal sent by the control unit, to boost a DC voltage output by the energy storage unit according to the discharge control signal, and perform discharge discharge on the energy storage unit. The charging and discharging electronic unit is further configured to output the boosted DC voltage to the inverter subunit.
The urban rail transit traction system according to claim 3, wherein

The inverter subunit is configured to receive a traction control signal sent by the control unit, to convert the boosted DC voltage outputted by the charging and discharging electronic unit into an AC voltage output to the traction motor according to the traction control signal, to drive The traction motor.
The urban rail transit traction system according to claim 3, wherein the inverter subunit is further configured to receive an electric brake recovery signal sent by the control unit to drive the traction motor according to the electric brake recovery signal The AC voltage regenerated at the time of braking is converted into a DC voltage output to the charging and discharging unit.
The urban rail transit traction system according to claim 5, wherein the charging and discharging electronic unit is configured to receive an electric brake charging signal sent by the control unit to convert the inverter according to the electric brake charging signal The DC voltage outputted by the subunit is stepped down to the energy storage unit to charge and store the energy storage unit.
The urban rail transit traction system according to claim 1, wherein the energy storage unit is a super capacitor or a battery or a parallel super capacitor and a battery.
The urban rail transit traction system according to claim 3, wherein the charging and discharging electronic unit comprises two IGBTs connected in series, and the inverter subunit comprises: three bridge arms connected in parallel with each other, each of the bridge arms Includes two IGBTs in series.
The urban rail transit traction system according to claim 8, wherein one end of the energy storage unit is connected between two series connected IGBTs of the charging and discharging electronic unit through a freewheeling reactor.
The urban rail transit traction system according to claim 2, wherein a high speed circuit breaker is further connected between the switch switching unit and the external power supply unit.