CAJ | 학술논문

为解决电压正反馈电流幅值扰动方法中因带入了电压扰动量与电网噪声可能导致系统不稳定的问题，提出了一种简单易实现的电流幅值扰动孤岛检测方法。该方法通过在给定电流波形中加入微小扰动，当孤岛发生时，电流环的跟踪控制作用会使得逆变器输出功率发生变化，进而导致公共点频率发生偏移，实现孤岛检测。文中推导出了电流总谐波畸变率与该幅值扰动因子间的关系，给出了扰动因子的取值范围，仿真结果及与主动移频法的盲区对比，论证了该方法的正确性、可行性和有效性。
위해결전압정반궤전류폭치우동방법중인대입료전압우동량여전망조성가능도치계통불은정적문제，제출료일충간단역실현적전류폭치우동고도검측방법。해방법통과재급정전류파형중가입미소우동，당고도발생시，전류배적근종공제작용회사득역변기수출공솔발생변화，진이도치공공점빈솔발생편이，실현고도검측。문중추도출료전류총해파기변솔여해폭치우동인자간적관계，급출료우동인자적취치범위，방진결과급여주동이빈법적맹구대비，론증료해방법적정학성、가행성화유효성。
This paper proposes an easy and simple current amplitude perturbation method for islanding detection in order to solve the unstable problem of the photovoltaic system caused by the voltage disturbance and power grid noise with the voltage positive feedback current amplitude perturbation method. In the method, a tiny perturbation is added into the given current waveform so that the tracking control action of current loop will change the inverter output power and cause the frequency of PCC (the point of common coupling) to shift when the islanding occurs, thus the islanding detection is implemented. In this paper, the relationship between current THD (total harmonic distortion) and perturbation factor is deduced and the perturbation factor range is given. Both the simulation results and the comparison with NDZ(non-detection zone) for AFD(active frequency drift) verify that the method is correct, feasible and valid.