Train-mounted traction converter

Abstract

The utility model discloses a train-mounted traction converter which comprises a direct-current power supply, a charging contactor U61, a line contactor Q61, a charging resistor R65, an isolation grounding switch S62, a first supporting capacitor C14, a second supporting capacitor C24, a third supporting capacitor C34, a fourth supporting capacitor C44, a first inversion module, a second inversion module, a third inversion module and a fourth inversion module. The direct-current power supply charges a first support capacitor C14, a second support capacitor C24, a third support capacitor C34 and a fourth support capacitor C44 through a charging contactor U61, a charging resistor R65 and an isolation grounding switch S62 respectively; and the direct-current power supply supplies power to a post-stage circuit through a line contactor Q61. According to the train-mounted traction converter provided by the utility model, more inversion modules can be installed on the basis of not changing the size of the original converter, the working efficiency of the inverter is improved, and the temperature rise of the converter is reduced. Only one traction motor is lost when a single inverter breaks down, configuration is more flexible, an asynchronous motor can be driven, a permanent magnet motor can also be driven, and the usability of the traction system is improved.

Description

Technical Field

[0001] The utility model relates to a train-mounted traction converter, belonging to the technical field of rail vehicles. Background Art

[0002] At present, due to the current trend of urbanization, more and more people taking public transportation, the increase in the number of subway trains and stricter air pollution regulations, people have begun to pay close attention to the energy-saving efficiency of traction inverters, which will put higher requirements on the design of traction inverter manufacturers.

[0003] Efficiency and power density are challenges that all current converter design manufacturers are facing. However, the system and busbar design of the module, as well as the wiring of the connecting conductors and the characteristics of the drive unit have a significant impact on the current between the parallel devices, which will lead to a certain deviation in the loss and cause different temperature rises between the inverter power modules. Due to the different number of traction motors required for trains, how to install more inverter power modules in the converter without significantly increasing the size of the converter, while ensuring the working efficiency of the converter, is also an urgent problem to be solved. Summary of the invention

[0004] The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art and propose a train-mounted traction converter, which can accommodate more inverter modules without changing the original converter volume, while improving the inverter working efficiency and reducing the converter temperature rise. The availability of the traction system will be greatly improved, and only one traction motor will be lost when a single inverter fails. The configuration is more flexible and can drive permanent magnet motors or asynchronous motors.

[0005] In order to solve the above technical problems, the technical solution of the utility model is:

[0006] A train-mounted traction converter, comprising a DC power supply, a charging contactor U61, a line contactor Q61, a charging resistor R65, an isolation grounding switch S62, a first supporting capacitor C14, a second supporting capacitor C24, a third supporting capacitor C34, a fourth supporting capacitor C44, a first inverter module, a second inverter module, a third inverter module and a fourth inverter module;

[0007] The DC power supply charges the first supporting capacitor C14, the second supporting capacitor C24, the third supporting capacitor C34 and the fourth supporting capacitor C44 respectively through the charging contactor U61, the charging resistor R65 and the isolation grounding switch S62, and the DC power supply supplies power to the subsequent circuit through the line contactor Q61;

[0008] A first discharge resistor R51 is connected in parallel to both ends of the first supporting capacitor C14, a second discharge resistor R52 is connected in parallel to both ends of the second supporting capacitor C24, a third discharge resistor R53 is connected in parallel to both ends of the third supporting capacitor C34, and a fourth discharge resistor R54 is connected in parallel to both ends of the fourth supporting capacitor C44;

[0009] The first inverter module is connected in parallel to both ends of the first support capacitor C14, the second inverter module is connected in parallel to both ends of the second support capacitor C24, the third inverter module is connected in parallel to both ends of the third support capacitor C34, and the fourth inverter module is connected in parallel to both ends of the first support capacitor C44;

[0010] The first inverter module, the second inverter module, the third inverter module and the fourth inverter module are each connected to a traction motor.

[0011] Furthermore, the circuit structures of the first inverter module, the second inverter module, the third inverter module and the fourth inverter module are the same. The first inverter module includes a U-phase bridge arm, a V-phase bridge arm, a W-phase bridge arm and a brake chopper bridge arm. The U-phase bridge arm is connected to the U-phase of the traction motor, the V-phase bridge arm is connected to the V-phase of the traction motor, the W-phase bridge arm is connected to the W-phase of the traction motor, and the brake chopper bridge arm is connected to the brake resistor of the traction motor.

[0012] Further, the U-phase bridge arm includes a U-phase power module U11-Q1, the V-phase bridge arm includes a V-phase power module U11-Q2, the W-phase bridge arm includes a W-phase power module U11-Q3, and the brake chopper bridge arm includes a brake chopper power module U11-Q4.

[0013] Furthermore, two MOSFET tubes are integrated in the U-phase power module U11-Q1, the V-phase power module U11-Q2 and the W-phase power module U11-Q3.

[0014] Furthermore, two IGBT modules are integrated in the brake chopper power module U11-Q4.

[0015] Furthermore, it also includes a ground fault detection module B67, and the DC power supply is connected to the charging contactor U61 and the line contactor Q61 respectively through the ground fault detection module B67.

[0016] The above technical solution is adopted. The four inverter modules of the utility model share a charging circuit. When charging, the charging contactor is closed, and the DC capacitor is charged through the charging resistor. When the charging voltage is reached, the line contactor is closed, the charging contactor is disconnected, and the charging resistor is disconnected. The inverter module adopts a new generation of 2-in-1 parallel IGBT and MOSFET, which can be installed with more inverter modules without changing the original converter volume, making the converter module smaller and lighter, and having low switching loss, improving the inverter efficiency, and reducing the temperature rise of the converter. The utility model can be widely used in high-speed rail, subway, urban vehicles and other vehicles in the rail transit industry, and can easily realize the functional requirements of axle control. A single inverter failure only loses one traction motor. The configuration is more flexible. It can drive both asynchronous motors and permanent magnet motors, which improves the availability of the traction system and can be used in more traction scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the use status of a train-mounted traction converter of the utility model;

[0018] Figure 2 The utility model is a principle block diagram of a train-mounted traction converter. DETAILED DESCRIPTION

[0019] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, this embodiment provides a train-mounted traction inverter, which adopts an axle control solution, that is, each inverter module independently controls a traction motor, and each carriage of the train needs to have 4 inverter modules to control 4 traction motors.

[0021] like Figure 2 As shown, the train-mounted traction converter of this embodiment includes a DC power supply, a charging contactor U61, a line contactor Q61, a charging resistor R65, an isolation grounding switch S62, a first supporting capacitor C14, a second supporting capacitor C24, a third supporting capacitor C34, a fourth supporting capacitor C44, a first inverter module, a second inverter module, a third inverter module and a fourth inverter module;

[0022] The DC power supply charges the first supporting capacitor C14, the second supporting capacitor C24, the third supporting capacitor C34 and the fourth supporting capacitor C44 respectively through the charging contactor U61, the charging resistor R65 and the isolation grounding switch S62, and the DC power supply supplies power to the subsequent circuit through the line contactor Q61;

[0023] A first discharge resistor R51 is connected in parallel to both ends of the first supporting capacitor C14, a second discharge resistor R52 is connected in parallel to both ends of the second supporting capacitor C24, a third discharge resistor R53 is connected in parallel to both ends of the third supporting capacitor C34, and a fourth discharge resistor R54 is connected in parallel to both ends of the fourth supporting capacitor C44;

[0024] The first inverter module is connected in parallel to both ends of the first support capacitor C14, the second inverter module is connected in parallel to both ends of the second support capacitor C24, the third inverter module is connected in parallel to both ends of the third support capacitor C34, and the fourth inverter module is connected in parallel to both ends of the first support capacitor C44;

[0025] The first inverter module, the second inverter module, the third inverter module and the fourth inverter module are each connected to a traction motor.

[0026] Here’s how it works:

[0027] like Figure 2 As shown, when the train is ready for traction, after the main circuit high-speed circuit breaker is closed, the DC power supply starts to supply power, and the charging contactor U61 is closed. The DC power supply pre-charges the four supporting capacitors C14, C24, C34, and C44 through the charging resistor R65 and the isolating grounding switch S62. When the capacitor voltage rises to a certain value within a certain period of time, the line contactor Q61 is closed, and the capacitor charging is completed.

[0028] When the main circuit high-speed circuit breaker is disconnected due to human intervention or failure, the electric energy on the supporting capacitors C14, C24, C34, and C44 is quickly released through the braking resistor of the traction motor by opening the chopper, and the discharge time is less than 1s. Alternatively, the discharge resistors R51, R52, R53, and R54 are connected in parallel at both ends of the supporting capacitors C14, C24, C34, and C44, and the voltage of the supporting capacitor can be discharged to below 50V within 5 minutes.

[0029] like Figure 2 As shown, the circuit structures of the first inverter module, the second inverter module, the third inverter module and the fourth inverter module of this embodiment are the same. Taking the first inverter module as an example: the first inverter module includes a U-phase bridge arm, a V-phase bridge arm, a W-phase bridge arm and a brake chopper bridge arm, the U-phase bridge arm is connected to the U-phase of the traction motor, the V-phase bridge arm is connected to the V-phase of the traction motor, the W-phase bridge arm is connected to the W-phase of the traction motor, and the brake chopper bridge arm is connected to the brake resistor of the traction motor.

[0030] Among them, the U-phase bridge arm includes a U-phase power module U11-Q1, the V-phase bridge arm includes a V-phase power module U11-Q2, the W-phase bridge arm includes a W-phase power module U11-Q3, and the brake chopper bridge arm includes a brake chopper power module U11-Q4.

[0031] like Figure 2As shown, the U-phase power module U11-Q1, the V-phase power module U11-Q2 and the W-phase power module U11-Q3 of this embodiment are integrated with two MOSFET tubes, and the brake chopper power module U11-Q4 is integrated with two IGBT modules. An axis control scheme is adopted. In order to install more inverter modules without changing the original converter volume, this embodiment introduces a new generation of 2-in-1 parallel IGBT and MOSFET, making the converter module smaller and lighter. It has more optimized electrical characteristics, a higher switching frequency to reduce the transmission loss on the traction motor and transformer; it has low switching loss, improves the inverter efficiency, and reduces the temperature rise of the converter.

[0032] like Figure 2 As shown, the DC power supply of this embodiment is connected to the charging contactor U61 and the line contactor Q61 respectively through the ground fault detection module B67. The ground fault detection module B67 can detect the ground fault occurring on the input and output sides of the traction converter. During operation, the ground fault from the power grid to the stator coil of the traction motor can be detected. The isolating grounding switch S62 of this embodiment ensures the electrical safety during the maintenance work on the traction and auxiliary equipment, and grounds the primary side of the main circuit high-speed circuit breaker. The current sensor B66 of this embodiment is used to detect the current value of the intermediate DC link, and the voltage sensor B5 is used to measure the voltage of the intermediate DC link support capacitor. These current and voltage information are used for the control calculation of the converter and can also be used to trigger the protection action. The output ends of the U phase and the W phase of the inverter module of this embodiment are connected with the current sensor B1 and the current sensor B3 to detect the U phase and the W phase current for the traction motor control.

[0033] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A train-mounted traction converter, characterized in that: It includes a DC power supply, a charging contactor U61, a line contactor Q61, a charging resistor R65, an isolation grounding switch S62, a first supporting capacitor C14, a second supporting capacitor C24, a third supporting capacitor C34, a fourth supporting capacitor C44, a first inverter module, a second inverter module, a third inverter module and a fourth inverter module; The DC power supply charges the first supporting capacitor C14, the second supporting capacitor C24, the third supporting capacitor C34 and the fourth supporting capacitor C44 respectively through the charging contactor U61, the charging resistor R65 and the isolation grounding switch S62, and the DC power supply supplies power to the subsequent circuit through the line contactor Q61; A first discharge resistor R51 is connected in parallel to both ends of the first supporting capacitor C14, a second discharge resistor R52 is connected in parallel to both ends of the second supporting capacitor C24, a third discharge resistor R53 is connected in parallel to both ends of the third supporting capacitor C34, and a fourth discharge resistor R54 is connected in parallel to both ends of the fourth supporting capacitor C44; The first inverter module is connected in parallel to both ends of the first support capacitor C14, the second inverter module is connected in parallel to both ends of the second support capacitor C24, the third inverter module is connected in parallel to both ends of the third support capacitor C34, and the fourth inverter module is connected in parallel to both ends of the first support capacitor C44; The first inverter module, the second inverter module, the third inverter module and the fourth inverter module are each connected to a traction motor.

2. The train-mounted traction converter according to claim 1, characterized in that: The circuit structures of the first inverter module, the second inverter module, the third inverter module and the fourth inverter module are the same. The first inverter module includes a U-phase bridge arm, a V-phase bridge arm, a W-phase bridge arm and a brake chopper bridge arm. The U-phase bridge arm is connected to the U-phase of the traction motor, the V-phase bridge arm is connected to the V-phase of the traction motor, the W-phase bridge arm is connected to the W-phase of the traction motor, and the brake chopper bridge arm is connected to the brake resistor of the traction motor.

3. The train-mounted traction converter according to claim 2, characterized in that: The U-phase bridge arm includes a U-phase power module U11-Q1, the V-phase bridge arm includes a V-phase power module U11-Q2, the W-phase bridge arm includes a W-phase power module U11-Q3, and the brake chopper bridge arm includes a brake chopper power module U11-Q4.

4. The train-mounted traction converter according to claim 3 is characterized in that: The U-phase power module U11-Q1, the V-phase power module U11-Q2 and the W-phase power module U11-Q3 each integrate two MOSFET tubes.

5. The train-mounted traction converter according to claim 3, characterized in that: The brake chopper power module U11-Q4 integrates two IGBT modules.

6. The train-mounted traction converter according to claim 1, characterized in that: It also includes a ground fault detection module B67, and the DC power supply is connected to the charging contactor U61 and the line contactor Q61 respectively through the ground fault detection module B67.

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