Abstract：In response to the existing problems of traditional diode based clamp type wind turbine inverters，a

hybrid clamp type structure was introduced. Based on the analysis of its working principle，a method for switching

the switch state and a vector optimization selection method that can avoid modulation waveform burr line voltage

were proposed，achieving balanced control of clamp capacitor and DC bus capacitor voltage. A third-order low-pass

filter method with initial angle calculation was proposed to optimize the virtual flux orientation control strategy for

the control of hybrid clamp type rectifiers in the unit. A direct power tracking control method for rectifiers based on

improved virtual flux orientation was also presented. Finally，simulation and experiments were conducted on the

system，confirming the correctness and effectiveness of the proposed method.

      Key words：wind power generation；permanent magnet direct drive；mixed clamp position；balance control；

virtual flux