Average power control method of cascaded H-bridge solid-state transformer

The invention discloses an average power control method for a cascaded H-bridge solid-state transformer. The method comprises the steps of determining a first rectification-stage voltage-sharing ringoutput signal and a second rectification-stage voltage-sharing ring output signal through collecting an isolation-stage output voltage, a first rectification-stage capacitor voltage and a second rectification-stage capacitor voltage of the cascaded H-bridge solid-state transformer; carrying out PI adjustment on the first rectification-stage voltage-sharing ring output signal so as to obtain a first average power phase shift angle, carrying out PI adjustment on the second rectification-stage voltage-sharing ring output signal so as to obtain a second average power phase shift angle, and carrying out PI adjustment on the isolation-stage output voltage and a preset reference target value so as to obtain a common phase shift angle; and determining the driving signal of the cascaded H-bridge solid-state transformer acc