A three-phase dual-buck full-bridge inverter without circulating current and its control strategy

Abstract

The invention discloses a three-phase double-Buck full-bridge inverter with no circulation and its control strategy, belonging to the technical field of power electronic converters. The converter is powered by two DC input voltage sources (V H , V L ), twelve switching tubes (S a1 ~S a4 , S b1 ~S b4 , S c1 ~S c4 ), eight diodes (D a1 、D a2 、D b1 、D b2 、D c1 、D c2 、D P 、D N ), six filter inductors (L a , L b , L c , L fa , L fb , L fc ) and three AC loads (Z a ,Z b ,Z c )constitute. A non-circulating current three-phase double Buck full-bridge inverter and its control strategy of the present invention realize two independent DC input sources supplying power to AC loads with only one inverter, and realize the connection of two single-input inverters Function. The non-circulating current three-phase dual Buck full-bridge inverter proposed by the present invention has no bridge arm direct connection and switch tube body diode reverse recovery problem, and can also work in the fixed frequency non-circulating current mode under the proposed control strategy, so the reliability is high, efficient. The invention is suitable for high-efficiency and high-reliability power supply applications such as new energy power generation and aviation airborne power supply.

Description

technical field [0001] The invention relates to a control strategy of a three-phase double-Buck full-bridge inverter without circulating current, which belongs to the technical field of power electronics, in particular to the technical field of DC-AC power conversion. Background technique [0002] With the development of more electric aircraft and new energy technologies, the requirements for the reliability, efficiency and power density of inverters are getting higher and higher. [0003] The bridge arm of the traditional bridge inverter consists of two switch tubes connected in series, and there is a risk of shoot-through. Therefore, a dead zone needs to be added between the two switching tubes. However, after the dead zone is added, the serious reverse recovery caused by the freewheeling of the body diode of the switching tube not only lowers the efficiency of the inverter, but also causes a serious threat to the reliable operation of the inverter. To this end, scholars...

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Problems solved by technology

[0004] Aiming at the deficiencies of the prior art, the present invention provides a control strategy for a three-phase dual-Buck full-bridge inverter without circulating current, which is used to solve the problems of low utilization rate of filter inductance and circulating current in the existing three-phase dual-input dual-Buck inverter

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