摘要
当在非检测区内电流扰动角和负载相角匹配时,基于周期交替电流扰动法可以有效地检测出孤岛现象。然而该方法存在注入扰动对输出电流的质量影响较大的缺点。结合一种改进的主动频移法,提出改进的周期主动频移式孤岛检测方法。该方法在相邻两个周期以不同的电流扰动方程作为参考电流波形,前一个周期中注入扰动使公共耦合点电压频率向上偏移,后一个周期使频率向下偏移。电网断电后,通过观察相邻周期公共耦合点电压频率差是否连续的正负交替变化来识别孤岛现象。经过理论分析和Matlab仿真验证,该方法可以准确地识别出非检测区内的孤岛效应,同时注入的扰动对输出电能质量影响很小。
When the load phase angle is equal to the angle of the current disturbance, a detection method based on the alternate current disturbance（ACD） is used to detect islanding. However, the injected disturbances have a serious influence on the quality of output current. Therefore, combined with an improved active frequency drift method, an improved islanding detection method based on the alternate active frequency drift is proposed. The proposed method injects a different current distortion into current waveform in the adjacent period. The disturbance makes the frequency of the voltage at the point of common coupling（PCC） shift up in the first period, and shift down in the next period. Islanding is detected by judging whether the error of the frequency at the PCC in adjacent period changes alternately in the form of the positive and negative signs. The proposed method is validated by theoretical analysis and Matlab simulation. The results verify that the proposed method can identify the islanding accurately from non-detection zone, and the injected disturbances have less impact on power quality.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2016年第16期50-55,共6页
Power System Protection and Control
基金
广东省科技计划项目(NO.2014A010106014)
广东省教育部产学研结合项目(NO.2012B091000111)
中央高校基本科研业务费专项资金资助(NO.21612412)
关键词
分布式发电
孤岛检测
周期交替
主动频移
非检测区
distributed generation
islanding detection
alternate
active frequency drift
non-detecting zone
