Three-phase motor train unit traction transmission power supply system

Abstract

The invention provides a three-phase motor train unit traction transmission power supply system which comprises a three-phase rectifying device, a DC / DC conversion device, and a traction inversion device ; the three-phase rectifying device comprises a three-phase alternating-current input port and three direct-current output port sets, each direct-current output port set comprises n direct-current output ports, n is larger than or equal to 1, and the number of n is set according to the voltage level of an external three-phase power source; the DC / DC conversion device comprises 3n independent power electronic transformers, the input port of each power electronic transformer is correspondingly connected with one direct current output port of the three-phase rectifying device, and the output ports of the power electronic transformers are connected in parallel and then serve as the direct current output port of the DC / DC conversion device; the input port of the traction inversion device is connected with the direct current output port of the DC / DC conversion device, and the output port of the traction inversion device is electrically connected with a traction motor. The three-phase rectifying device is directly used for taking electricity from the external power supply to drive the traction motor, a vehicle-mounted traction transformer can be omitted, the value of n can be set according to different voltage grades, and the applicable voltage grade range is wide.

Description

technical field [0001] The invention relates to the technical field of electrified railways and urban rails, in particular to a three-phase EMU traction drive power supply system. Background technique [0002] Compared with DC traction motors, AC traction motors have the advantages of high power density, low price, simplicity and reliability, and good anti-idling performance. Therefore, they are replacing DC motors as the main power source for mainline electrified railways and urban rail transit traction. Electrified railways use single-phase power supply, and AC traction motors on electric locomotives or EMUs need to be driven by three-phase inverters. In order to realize this conversion function, the electric locomotive or the EMU is equipped with an AC-DC-AC traction converter, which first converts the single-phase AC into DC, and then converts it into a three-phase AC through the inverter, and realizes speed regulation through voltage regulation and frequency modulation....

AI Technical Summary

Problems solved by technology

However, the vehicle-mounted traction transformer has a large volume and weight, which increases the axle load of the locomotive or EMU, increases losses, reduces efficiency, and affects power density, restricting the further improvement of EMU speed

[0003] In order to cancel the on-board traction transformer, the applicant applied for "A Traction Drive Power Supply System for EMUs" (202011206524.8), but this application scheme is only applicable to traction power supply systems with single-phase traction power supply and low catenary voltage. Under the same capacity (capacity), three-phase generators, motors, and transmission lines are more material-saving than the manufacture and construction of single-phase similar components, and the structure is simple and the performance is excellent. Therefore, the three-phase traction power supply system is expected to replace single-phase traction The power supply system has become a new traction power supply system. On this basis, it is worth studying to design a three-phase EMU traction drive power supply system that can be applied to different voltage levels and can still cancel the on-board traction transformer.

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