CAJ | 학술논문

孤岛检测是并网逆变器必备的一种功能。针对传统主动移频(Active Frequency Drift, AFD)孤岛检测法存在的检测时间较长和检测盲区(Nondetection Zone, NDZ)较大的问题，提出一种新型的AFD孤岛检测法。通过在原始电流参考波形中注入接近余弦的扰动波形，使参考波形在产生孤岛检测所需无功功率相同时，能有效减小对电能质量的影响。对参考波形进行数值分解，分析该方法的THD与Q/P之间关系以及NDZ分布情况，并与传统AFD法进行比较。仿真结果表明，该方法具有检测时间更短和NDZ更小，同时对电能质量影响小的特点。
고도검측시병망역변기필비적일충공능。침대전통주동이빈(Active Frequency Drift, AFD)고도검측법존재적검측시간교장화검측맹구(Nondetection Zone, NDZ)교대적문제，제출일충신형적AFD고도검측법。통과재원시전류삼고파형중주입접근여현적우동파형，사삼고파형재산생고도검측소수무공공솔상동시，능유효감소대전능질량적영향。대삼고파형진행수치분해，분석해방법적THD여Q/P지간관계이급NDZ분포정황，병여전통AFD법진행비교。방진결과표명，해방법구유검측시간경단화NDZ경소，동시대전능질량영향소적특점。
Anti-islanding detection is a mandatory function of grid-connected inverters. This paper proposes a novel active frequency drift (AFD) islanding detection method to solve the problems of the classic AFD method, such as longer detection time and larger non-detection zone (NDZ). In the proposed AFD method, an approximating cosine disturbance current waveform is injected into the original reference current waveform, so that there is less side influence on power quality when the reactive power generated by reference current waveform equals. This paper analyzes the relationship between the total harmonic distortion (THD) and Q/P and the distribution of NDZ in the proposed method through the value decomposition of the proposed reference current waveform, and compares the new method with the classic AFD method. The simulation results show the proposed method has shorter detection time, smaller NDZ and less influence on power quality.