Digital voltage control for DC energy storage unit of dynamic voltage restorer

The working principle of active power factor correction (APFC) technology is expounded. To eliminate harmonics and reactive current during the charging process of DC energy storage unit of the dynamic voltage restorer (DVR), leading APFC technology into the voltage control of DC energy storage unit of dynamic voltage restorer, the digital voltage control algorithm for DC energy storage unit of DVR is proposed and the design approach for voltage controller and current controller is given. Simulation results show that by use of APFC technology the harmonics and reactive current in charging current of DVR can be actively eliminated and both voltage stability and dynamic response of DC energy storage unit can be improved.