Three-phase auxiliary inverter

Abstract

The invention discloses a three-phase auxiliary inverter, which comprises a main circuit and a control circuit, wherein the control circuit detects and controls the main circuit; the main circuit comprises an input filtering circuit, a DC / DC conversion circuit, a DC / AC inverter circuit and an output filtering circuit; and the DC / DC conversion circuit comprises a half-bridge inverter circuit adopting a high-frequency transformer and a full-bridge rectifier circuit. When the inverter is on, the control circuit performs system self-checking, the main circuit works under the condition of no fault, the input filtering circuit filters an input power supply and closes a short-circuit contactor after the charging is finished, the control circuit sends a half-bridge inverter pulse, the DC / DC conversion circuit works and converts the input direct current power supply into a steady intermediate direct current voltage, then the steady intermediate direct current voltage is inverted into a three-phase SPWM wave through the DC / AC inverter circuit, and the three-phase SPWM wave is filtered into a three-phase sine wave through the output filtering circuit and supplies the electricity to a three-phase load. The implementation of the three-phase auxiliary inverter reduces the voltage stress borne by switching devices, and reduces the weight and the volume of power supplies.

Description

technical field [0001] The invention relates to a rail vehicle auxiliary power supply device applied in the field of rail transit, in particular to a three-phase auxiliary inverter power supply that adopts a new main circuit structure and is applied to various rail vehicle air conditioners, lighting, battery charging and control systems . Background technique [0002] At present, for the auxiliary power supply of air conditioning, lighting, battery floating charging and control systems of rail vehicles (subway cars and light rail vehicles), two solutions are generally adopted: one is the auxiliary power supply of the motor generator set, which has low power and low efficiency. , high noise, poor regulation of voltage and frequency, brush dust pollutes the environment, requires frequent maintenance, backward technology, and tends to be eliminated; the other is the thyristor inverter auxiliary power supply, because the thyristor needs high power to turn off the circuit and abs...

AI Technical Summary

Problems solved by technology

This kind of circuit is characterized by simple circuit structure, few components, and convenient control, but the output voltage is easily affected by the fluctuation of the input voltage of the power grid, the input and output are not isolated, the quality factor of the output voltage is poor, the harmonic content is large, and the load Shortcomings such as low use efficiency, these shortcomings in electrical performance determine that it is not suitable for maglev trains

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