Current-type DC-AC converter for driving low-input-voltage motor and soft switching control thereof

Abstract

The invention discloses a current type DC-AC converter for driving a low-input-voltage motor. The current type DC-AC converter is formed by sequentially cascading a DC power supply, a high-gain buck-boost chopper circuit with a ZVS active clamp, an m-phase current type inverter circuit (m is a positive integer) and an output filter circuit. The DC power supply firstly passes through the high-gain buck-boost chopper circuit and then outputs high-frequency PWM current pulse waves, and then passes through the m-phase current type inverter circuit and the output filter circuit to obtain high-quality AC voltages. The high-gain buck-boost chopper circuit with the ZVS active clamp can work in a boost mode or a buck mode according to different output AC voltages, and an energy storage switch S can realize zero-voltage turn-on by controlling the turn-on time of an active clamp branch switch SC. The converter has the characteristics of single-stage boost inversion, high boost capability, wide output voltage regulation range, high conversion efficiency, high power density, small common-mode current and the like, and has a good application prospect in a low-input-voltage motor driving occasion.

Description

Technical field: [0001] The invention relates to a current-type DC-AC converter for driving a low input voltage motor, which belongs to the field of electric energy conversion. Background technique: [0002] With the development and progress of science and technology, new energy vehicles have begun to have a place in the traditional automobile industry. New energy vehicles not only integrate advanced vehicle control and power technology, but also have a new structure and are environmentally friendly. At present, new energy vehicles can be divided into three categories: pure electric vehicles, plug-in hybrid vehicles and fuel cell vehicles. The core components of electric vehicles include three major components: motor, electric drive and battery. Among them, the motor drive control system is the core part of pure electric vehicles, and an excellent DC-AC converter for motor drive is crucial to the performance of electric vehicles. [0003] At present, because there are man...

AI Technical Summary

Problems solved by technology

Because the current inverter circuit usually uses a voltage-type inverter circuit, the pre-stage boost circuit is essential, but the efficiency of the two-stage power conversion strategy is low, and the output voltage range is limited, resulting in a small range of motor speed regulation , performance is limited

[0004] In view of the shortcomings of the current two-stage DC-AC power conversion strategy, the current source inverter has been widely studied. The existing current source inverter is to connect a large inductor in series between the inverter bridge arm and the input DC power supply, and then The large inductance is equivalent to a current source, so that it exhibits the characteristics of a current source in the working process, realizes boost control, and can realize large output voltage and wide-range output voltage regulation, but the existing traditional current-source inverter cannot Step-down, or the situation that the output voltage is not high enough, needs further research and improvement

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