Vienna rectifier midpoint voltage dc offset suppression method

Abstract

The application discloses a midpoint voltage DC offset suppression method for a Vienna rectifier and belongs to the technical field of Vienna rectifier control. The application is aimed at the problem that the bipolar DC bus of the Vienna rectifier has midpoint voltage DC offset under the light load condition of unbalanced load. The application comprises the following steps: calculating the maximum q-axis current of odd and even sectors according to the corresponding relationship of grid current vectors and reference voltage vectors in a voltage space vector diagram; simultaneously calculating the q-axis current amplitude; then calculating the q-axis current instruction value and the d-axis current instruction value; further calculating the d-axis reference voltage u d and the q-axis reference voltage; finally, performing dq-axis system to alpha-beta-axis system conversion on the d-axis reference voltage u d and the q-axis reference voltage u q , and combining space vector modulation to obtain the driving signal of the Vienna rectifier, so that the midpoint voltage DC offset suppression is realized. The application is used for suppressing the midpoint voltage DC offset of the Vienna rectifier.

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