Research on Feasibility of Large-scale New Energy Islanding Detection Scheme Based on Impedance Measurement

A lot of research has been done on islanding detection of photovoltaic(PV) power system. In these schemes, islanding can be detected by schemes based on convertor control. The range of these research is islanding occurs in a single power station or distributed generation system. However, experiments proof that islanding also occurs in large-scale wind farms. Classical islanding detection schemes such as active frequency drift scheme or reactive power disturbance scheme may not suitable to this situation due to the different parameter when islanding occurs in large-scale new energy power stations. Meanwhile, islanding detection scheme based on system impedance detecion is an ideal scheme to detect islanding in large-scale new energy power stations. However, reaearch on islanding detection scheme based on system impedance only compute the impedance of the outlet end of the convertor, in other words, in a single power station and overlook the problems when the scheme is applied to large-scale new energy power stations, such as power quality problem and signal attenuation problem and so on. This artical will analyze the feasibility of using system impedance to detect islanding in large-scale new energy power stations.