间歇性双边无功功率扰动孤岛检测策略

孤岛检测是分布式并网发电系统的必备功能，因为孤岛的发生一般不可预测且危害极大。分析了恒功率控制模式下的并网逆变器在孤岛运行时的电压和频率，计算得出逆变器输出含无功时的非检测区。然后，给出了间歇性双边无功功率扰动的孤岛检测方法，得到消除非检测区的条件并设计了扰动参数。最后进行实验验证，结果表明该孤岛检测策略满足检测要求，对并网功率因数影响很小。

Intermittent Bilateral Reactive Power Variation Islanding Detection Strategy

Islanding detection is an essential function of distributed grid-connected power generation systems, as the islanding occurrence is unpredictable and very harmful. The voltage and frequency of the constant-power controlled grid-connected inverter working in the islanding state has been studied. The none detection zone (NDZ) is calculated when the output of the inverter has reactive power. Then, intermittent bilateral reactive power variation anti-islanding strategy was proposed. The conditions to eliminate NDZ are presented and the variation parameters are designed. Finally, experiments results indicate that the proposed method could meet requirement and has little influence on power factor.