一种混合式光伏逆变器反孤岛策略

A hybrid photovoltaic inverter anti-islanding strategy

逆变输出同本地消纳功率平衡时,被动式反孤岛策略会出现非检测区,而主动式反孤岛策略对电能质量有影响。文章提出一种基于过欠电压/频率和功率扰动相联合的混合式光伏逆变器反孤岛策略,该控制策略是将逆变器输出功率与负载功率进行比较,得到控制信号,进而在孤岛发生时根据不同工况在两种检测方法中切换。建立了光伏逆变器孤岛检测仿真模型,仿真结果表明,文章反孤岛策略具有无检测盲区、产生谐波小等优点。

In view of the passive anti-islanding strategy appears non-detection zone when the inverter output balances with local consumptive power, and active anti-islanding strategy has an impact on the power quality, a hybrid photovoltaic inverter anti-islanding strategy, which combines measurement of voltage or frequency with active power disturbances, is proposed. A control signal is obtained by comparing the detected inverter output power with the load power, one of two detection methods is switched in depending on the operating conditions when islanding occurs. A photovoltaic inverter islanding detection simulation model is established on the basis of PSCAD/EMTDC. The results show that the proposed strategy has advantages such as no non-detection zone, small harmonic etc.