Study On Control Method Of High Frequency Link Inverter With Matrix Converter

Matrix converter, as an novel topology green"all silicon"power converter, has experienced a tremendous attention recently because of its advantages of frequency conversion in a single-stage processing without large reactive energy storage elements, controllable input power factor, variable output voltage with unrestricted frequency, flow of bidirectional power. It has great researching value and broad application prospect.The development situation of high frequency link invert technology and matrix converter is discussed firstly. The advantages and disadvantages of several typical voltage source and current source mode high frequency link technology are analyzed. Then reviewed the various control strategies to matrix converter.The paper in second chapter focused on the research of high frequency link inverter which adopted single phase to three phase matrix converter as later stage topology and utilized DC/HFAC/LFAC two stage power conversion to achieve inverter function. A novel topology de-coupling control scheme is proposed. According to the voltage polarity produced by high frequency invert bridge, the latter matrix converter can be decomposed into two conventional three phase voltage source mode inverter and the control strategy fit for voltage source inverter can be introduced into matrix converter. Compared with emphasized on studied or optimized matrix converter control scheme only, topology de-coupling control method can greatly reduce the analysis difficulty of matrix converter. To facilitate the theoretical analysis,"Two-way bridge arm"new concept is presented. Based on topology de-coupling control idea, mathematical model and simulation model were established and simulation study is performed with Saber software.The theoretical analysis of pulse density modulation strategy and phase shifted control with use of pulse density modulation control method is studied in third chapter. Simulation model is built to verify the proposed strategy.In the fourth chapter, a novel control strategy of Sinusoidal Pulse Width and Position Modulation is adopted for high frequency invert bridge and detailed mathematical derivation for its realization principle is presented. Its high frequency transform process is explained. Simulation experiments with the process of above theoretical analysis is verified and concluded that working in SPWPM mode, high frequency inverter bridge output voltage components concentrated in one half of the carrier frequency and transformer operated in high frequency condition, really showed the advantage of high frequency link.Finally, in order to verify the feasibility of the proposed control strategy, based on the theoretical analysis and simulation, the inverter prototype is built, especially the magnetic components, filter and dead time driving signal received were designed in detail. The output filter is optimized using RLC with damping resistance. Compared with the traditional second-order LC filter, RLC filter not only attenuated high frequency components strongly, but also improved the stability of the output voltage. Bi-directional switch connected in common source style. Based on the control core circuit of TMS320LF2407 DSP, experimental research with digital control program is carried out by using Altera's EPM240T100C5N CPLD integrated logic chip to complete the modulated signal processing and achieve Sinusoidal Pulse Modulation on Matrix Converter. Experimental results show that the proposed control strategy on the validity of theoretical analysis and control scheme is feasible. The summary and outlook of the researching subject is given.