Design and Control Method of Power Conversion System for Emergency Power Supply

Power conversion system is the key equipment to realize two-way energy transfer between energy storage battery and AC power grid. This paper introduces a design and control method of power conversion system for emergency power supply. The power conversion system can select grid connected operation or independent on load operation to meet the multi scenario application requirements of emergency power supply site. During grid connected operation, the input power is controlled by controlling the input current, and then the output voltage at the DC side is controlled. During independent load operation, the load voltage and frequency are controlled by controlling the output voltage amplitude and frequency of the converter. The proposed constant voltage current limiting control strategy can maintain the DC bus voltage near the reference value and improve the reliability of battery charge and discharge.