CAJ | 학술논문

针对传统微网并网方式供电可靠性低、稳定性差、潮流无法控制等问题，该文设计了一种基于电力电子变压器的新型微网并网装置，提出了其在不同运行模式下的控制策略。对于电网跟随控制下的微网系统，并网装置采用V/f控制策略；对于微网并网点潮流恒定控制下的微网系统，并网装置采用PQ控制策略。利用电磁暂态仿真软件PSCAD/EMTDC对所提的控制策略进行了仿真，结果表明，该文提出的并网装置及控制策略不仅可实现微网与大电网的联网运行，还能精确控制并网点潮流，减小并网过程中微网DG、负荷波动时对主网的影响。
침대전통미망병망방식공전가고성저、은정성차、조류무법공제등문제，해문설계료일충기우전력전자변압기적신형미망병망장치，제출료기재불동운행모식하적공제책략。대우전망근수공제하적미망계통，병망장치채용V/f공제책략；대우미망병망점조류항정공제하적미망계통，병망장치채용PQ공제책략。이용전자잠태방진연건PSCAD/EMTDC대소제적공제책략진행료방진，결과표명，해문제출적병망장치급공제책략불부가실현미망여대전망적련망운행，환능정학공제병망점조류，감소병망과정중미망DG、부하파동시대주망적영향。
This paper constructs a novel topology of microgrid with power electronic transformer ( PET ) as grid-connected device .Based on this , a coordinated control strategy for grid-connected device was proposed . When microgrid operates in grid-following mode , V/f control strategy is used for output inverter of power electronic transformer .When constant power flow at point of common connection is desired , PQ control strategy is used .The simulation and analysis demonstrate that the voltage and frequency of microgrid has good stabilizing performance in the two modes .Grid-connected device with PET contributes to precise control for power flow at PCC and reducing the effect on utility during synchronization process caused by DG and load fluctuation .