Power electronic transformer soft start method based on energy feedback

• Main Authors: NIE CHUANJIE, YAN DONG, CHEN XIAOLEI, XIONG FEI, YANG HONGYU, WU PENG
• Format: Patent
• Language: Chinese; English
• Published: 09.07.2021
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

The invention belongs to the technical field of power electronics, and particularly relates to a power electronic transformer soft start method based on energy feedback, and the method comprises the steps: analyzing the relation between an inductance peak current and an internal shift ratio after obtaining a high-voltage DC side voltage, and designing an increase track of the internal shift ratio. The invention provides a low-voltage side energy feedback control strategy aiming at the impact current generated when the CHB is converted from uncontrollable rectification to PWM rectification, a DAB bidirectional power flow characteristic is utilized, part of energy of a low-voltage direct current side is fed back to a high-voltage side, the voltage of the high-voltage side reaches a closed-loop reference value so as to eliminate the impact current generated when the CHB is connected to a grid, and thus soft start of the power electronic transformer is completed. According to the start strategy provided by the in