Based On The New Type Two-step Commutation Strategy Of RMC And Its Experimental Systerm Study

Reduced matrix converter(RMC) derived from topology of matrix converter, as a new type of power converter has the following advantages: the waveform of grid side current is sinusoidal, input power factor is adjustable; output without energy storage capacitors, long service life, small volume, light weight, reliability and high power density; can achieve true four quadrant operation and easy to modular implementation. This paper analyzes the topology of the high-frequency chain RMC, bi-polar current space vector pulse-width modulation(B-C-SVM) strategy, presents the new type two-step commutation strategy of RMC, software simulation is built and the experimental prototype is verified.Firstly, the paper introduces the topology, modulation strategy and its application status of three kinds converters circuit based on RMC(matrix rectifier, three-phase to single-phase ac conversion circuit, high-frequency chain RMC) and focus on introduces the modulation strategy, application status of high-frequency chain RMC and the research status about commutation strategy of matrix converter, the paper analyzes the B-C-SVM strategy of the current mode high-frequency chain RMC, the simulation is verified. The paper presents the new type two-step commutation strategy of RMC, in order to prevent short circuit of input power from the three input phase voltage magnitude close, adding the dead area in the commutation process is proposed, the security of RMC commutation process is improved. At the same time according to the characteristics of the power switch device, the new type two-step commutation method of RMC is proposed, commutation steps is simplified, shorten the commutation time of system, so the commutation of RMC can more safety and reliable.Finally, the paper builds RMC experiment prototype that using the B-C-SVM strategy and the proposed new type two-step commutation strategy. Experimental prototype includes hardware system and software system, in the hardware system part, the design of input LC filter, bidirectional switches of main circuit, IGBT snubber circuit, IGBT drive circuit, signal measurement and conditioning circuit, fault protection circuit and the parameters calculation of relevant components is given; In software system part, introduces program design of the DSP(TI-DSP28335) and CPLD(Altera-EPM570) as the core controller. Based on the faster computing speed and powerful data processing capacity of DSP28335, current and voltage signals sampling, the B-C-SVM strategy, the coding of vector operation time and fault protection function can completed quickly and real-time. CPLD has powerful combination logic processing ability and its programming language has the advantage of parallel execution, the decoding of vector operation time, commutation strategy, output 12 PWM drive signals and fault protection function can completed better. In this paper, fuction program flow charts and the waveform of RMC experiment prototype is gived, the experimental results verify the validity and effectiveness of the B-C-SVM strategy and the proposed new type two-step commutation strategy.