Flexible direct current transmission current converter harmonic wave and loss computing method based on modular multilevel converter (MMC)

The invention relates to a flexible direct current transmission current converter harmonic wave and loss computing method based on a modular multilevel converter (MMC). The method comprises the following steps: 1) computing the steady-state current of MMC bridge arms; 2) showing the impulse waveform of each power module of six sets of MMC bridge arms which are formed by connecting in series by computing again; 3) computing the current of a switch component and the voltage fluctuation of power module capacitors according to the impulse waveform and the bridge arm current; 4) computing each harmonic characteristic index of a current converter alternating-direct current port according to the impulse waveform and the voltage fluctuation of the power modules; and 5) obtaining the loss of the switch component by computing according to the impulse waveform and the current of the switch component. According to the method, each harmonic characteristic value of the MMC current converter alternating-direct current port, the loss characteristics of the switch component and the current converter and the like can be computed conveniently and quickly, and scanning computing of the harmonic and loss characteristics under a full-operation condition can be achieved easily.