基于q轴电流扰动的孤岛检测方法

Novel islanding detection method based on q-axis current disturbance

提出了一种基于q轴电流扰动的孤岛检测方法。该方法通过引入q轴电流扰动,使RLC负载在电网因故障断开时产生频率偏移,从而检测出孤岛。引入的q轴电流扰动结合了无功功率变化和频率变化,当系统在电网下运行时,无功功率变化和频率变化接近于零。因此该方法具有非常小的谐波畸变率,保证了良好的电能质量。基于Matlab/Simulink软件包的仿真结果表明,该方法在设定的参数条件下能在1 s内检测到孤岛现象,且对系统具有非常小的影响。

A novel islanding detection method was put forward based on q-axis current disturbance. This method, by introducing q-axis current disturbance, made the RLC load generate frequency offset to detect the island in the case that the power network was disconnected due to certain fault. The introduced q-axis current disturbance was connected with reactive power variation and frequency variation whose values were close to zero when PV system was operated in grid-connected mode. Therefore, the suggested method had the advantage of tiny harmonic distortion and good power quality. The simulation results based on the MATLAB/Simulink software show that the novel islanding detection method could detect the island in 1 second and had little effects on the system under the condition of the set parameters.