Auxiliary inverter power source

Abstract

The invention provides an auxiliary inverter power source. The auxiliary inverter power source comprises an input switch unit, a DC / DC unit and an auxiliary inverter unit, wherein the input switch unit, the DC / DC unit and the auxiliary inverter unit are sequentially connected. The input switch unit comprises a contactor K1, a resistor R1 and a contactor K2 connected with a pre-charging loop in parallel, wherein the contactor K1 and the resistor R1 serve as the pre-charging loop and are connected in series; the DC / DC unit comprises an input filter loop, a transformer and an output rectification loop, wherein the input filter loop, the transformer and the output rectification loop are sequentially connected; the auxiliary inverter unit comprises an inverter loop and a three-phase filter loop. According to the auxiliary inverter power source, an auxiliary inverter power source of a traditional industrial frequency transformer is replaced with a medium frequency transformer, the voltage grade of an input power source is reduced, the using number of a high-voltage IGBT is reduced, the design cost and the total weight are reduced, the conversion efficiency of energy is greatly improved, and the auxiliary inverter power source has the high energy-saving benefits.

Description

technical field [0001] The invention belongs to the field of vehicle traction, in particular to an auxiliary inverter power supply in vehicle traction. Background technique [0002] As a key component of the vehicle traction system, the auxiliary inverter power plays a vital role in the vehicle. During the normal operation of the vehicle, it is responsible for providing three-phase and single-phase AC power for AC loads such as the vehicle's passenger room air-conditioning unit and ventilation device, air compressor, electric heater, and AC lighting. The safety and reliability of the auxiliary power system have an important impact on the normal operation of the vehicle. [0003] The electrical topology of the auxiliary inverter varies greatly depending on the vehicle power supply mode. At present, the power supply of ordinary railway passenger cars in my country mostly adopts simple phase-controlled rectification to rectify the AC 860V AC into DC600V DC and then invert it ...

AI Technical Summary

Problems solved by technology

[0005] When the auxiliary power supply input voltage is high, such as subway DC 1500V, the IGBT (insulated gate bipolar power tube) in the inverter PU must use six 3300V or higher voltage level IGBTs, and the high-voltage IGBTs are expensive and difficult to drive , which undoubtedly increases the system cost; secondly, the high-voltage IGBT switching loss is large and the heat generation is serious, which requires a larger heat sink in the design of the PU module heat sink, which increases the installation size and cost of the equipment; in addition, The high-voltage IGBT switching frequency is low, and the harmonic frequency in the three-phase PWM wave output by the inverter is low. It is necessary to increase the inductance or capacitance value in the three-phase filter circuit to effectively filter the harmonics.

[0006] Considering safety issues, the input and output circuits are usually required to be isolated by transformers, but conventional power frequency transformers cannot make further breakthroughs in terms of power transformation efficiency and volume weight, which limits the design efficiency of the entire auxiliary inverter and increases equipment weight and volume

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