一种基于DSP新型三相逆变器谐振电路的控制方法

本文阐述了一种新型基于DSP三相DC-AC逆变器零电压开关(ZVS)拓扑电路的工作原理及其谐振控制方法，并就该控制方法中的问题及其对ZVS的影响作了详细分析，同时给出了相应的仿真波形与实验结果。

The Research on Control Strategy of a Novel Resonant Topology for Three-Phase Inverter Based on DSP

In this paper the operational principle of a novel ZVS topology for three-phase DC-AC inverter based on DSP are first described in detail. The whole working process of the equivalent circuit of this resonant topology can be divided into 9 modes, during which not only the main power switches but also the auxiliary power switches are all soft-switched. The resonant waveforms are illustrated to show how to realize ZVS condition. nThe control method utilizing TMS320F240 DSP to trigger the auxiliary power switches Vc1,Vc2 are briefly introduced. This control strategy is simple and reliable. Realtime measure of the resonant inductance current iLr can be omitted and the switching of the auxiliary power switches can be synchronized with PWM in the main circuit. Problems are found out through experiment that the DC voltage UPN can return to zero successfully if enough load current IL is afforded so that the resonant tank can be generated, otherwise UPN cannot reach zero to form ZVS condition. These problems are analyzed theoretically according to the difference between the resonant voltage and current track-plots drawn under the circumstances of different IL. The simulated waveforms and the experimental results are both given out to show the vital influence of the load current IL on the successful realizing ZVS.