基于级联H桥的柔性互联类正弦调制方法OA

The soft open point(SOP),as a sort of promising flexible power electronic device in future smart distribution network,can take the place of normal open point to achieve flexible interconnection and power regulation.The shared module soft open point(SMSOP),as a new flexible interconnection topology,has the advantages of high efficiency,small size and low cost.However,SMSOP is prone to overmodulation when using conventional pulse width modulation(PWM)and has high losses if the shared module accounts for more.A new sine-wave-like modulation method is proposed.The sine-wave-like modulation adds a square-wave platform on the basis of the sine-wave modulation.Sine-wave modulation is used at the start and end of each half-cycle to prevent over-modulation at zero-crossing time;square-wave modulation is used in the middle to reduce the switching losses of the shared modules.Finally,the correctness and effectiveness of the new modulation strategy are verified by building a three-phase experimental platform.