Research Of Inverters With High Frequency Link Based On The SPWPM And Soft Switching Technology

As we know, the quality of electrical energy is more and more demanding in the modern industrial applications. Studies on high power density , high efficiency and as well as high frequency link inverter power supply are one of the hot points in power electronics field. In the Inverters controlled by the mode of sinusoidal pulse width modulation, the huge low frequency transformer is the main barricade unavoidably to develop high power density and high efficiency inverters by using this control mode. So a new type of high frequency link inverter control strategy SPWPM (Sinusoidal Pulse Width and Phase Modulation) is introduced consequentially.the essence of the new type of high frequency link SPWPM converter is that : Through changing the composition of single polarity SPWM wave, a new SPWPM wave can be obtained, which included the whole information of SPWM wave except the frequency of the modulating wave formally. Therefore, the new wave can be transmitted by high frequency transformer. It will be returned to the conventional SPWM wave by demodulation in secondary side of the transformer, according to the established mathematical model of SPWPM inverter stage, then a more brief and understandable demonstration is gained, the conclusion and the simulation subsequently certified that the theoretical analysis is right.The operation principle of full bridge phase shift controlled ZVS PWM DC/DC converter is the bases of this dissertation, so the performance of the circuit in twelve different stage is disscused, and then analyzed the conditions and strategies for realizing the ZVS as well as the reasons of the duty-cycle losing.A new type of phase shift zero voltage switch-SPWPM inverter strategy is proposed , which is a good combination of the SPWPM strategy and traditional phase-shift ZVT-PWM soft switching technology. By controlling the turn-on subsequence of the power switches in the oblique diagonal line of the two bridge arms, while the transformer still transmits the SPWPM wave, the circuit is working in the resonant condition in the turn-on and turn-off process of the power switches, therefore makes the ZVS technology can be realized in this type of inverter. According to analyzing the working process of the phase-shift ZVS-SPWPM converter, the parameters of the main circuit is designed, subsequently the simulation by the software PSPICE certified that ZVS technology is commendably realized in the convert, which provides the theory bases for further study according to the converter.