CAJ | 학술논문

提出了一种采用双级无隔离变压器的新型单相光伏并网逆变器拓扑，由于光伏池板与电网零线直接相连，可消除光伏池板对地的共模电压，解决了共模漏电流问题。所提拓扑采用了高频倍压的方式实现升压变换器与并网逆变器的连接，避免了三电平并网逆变器存在的中点电位二次脉动问题，降低了直流侧滤波电容的容量需求。为实现对单相并网电流的无误差控制，并网控制中采用比例谐振控制器，增加了系统的稳定性和提高了并网电流质量。仿真与实验结果均表明所提光伏并网逆变器拓扑的可行性。
제출료일충채용쌍급무격리변압기적신형단상광복병망역변기탁복，유우광복지판여전망령선직접상련，가소제광복지판대지적공모전압，해결료공모루전류문제。소제탁복채용료고빈배압적방식실현승압변환기여병망역변기적련접，피면료삼전평병망역변기존재적중점전위이차맥동문제，강저료직류측려파전용적용량수구。위실현대단상병망전류적무오차공제，병망공제중채용비례해진공제기，증가료계통적은정성화제고료병망전류질량。방진여실험결과균표명소제광복병망역변기탁복적가행성。
The topology of a novel single-phase two-stage grid-connected Photovoltaic (PV) inverter without isolation transformer is proposed. The direct connection of PV panels with the zero line of power grid can eliminate the common mode voltage of PV panel to the ground, so the problem of common mode leakage current is solved. In the proposed topology the high-frequency voltage-doubling mode is utilized for the connection of boost converter with grid-connected inverter to avoid the secondary pulsation of neutral point potential existing in three-level grid-connected inverter, thus the demand on the capacity of filter capacitor at DC side is reduced. To implement the astatic control of single-phase grid-connected current, the proportional-resonant (PR) controller is adopted in the grid-connection control to enhance the stability of control system and improve the quality of grid-connected current. Results of simulation and experiments show that the topology of the proposed grid-connected PV inverter is feasible.