ABSTRACT The Low Voltage Ride Through (LVRT) is an important requirement in fault conditions for any power system specially microgrids. When the fault occurs, the overcurrent and unbalanced voltage are yielded and these result in serious damages in inverter-based Distributed Generators (DGs) in the microgrid. To prevent this phenomenon, many types of research have been guided to limit the current in faulty conditions and to improve and balance the PCC voltage to be without any distortions. In this paper in islanded mode with reactive power injection during the fault occurrence, the LVRT method is proposed. This reactive power is injected to compensate the voltage dip and simultaneously limit the overcurrents in faulty phases. Also using this method, the faultless phases are not degraded and have no overvoltages. It is noticeable that two inverters in this paper assumed with varying droop gains and so the current and power of them must be divided relative to their droop gains both in faulty and faultless conditions. The simulation results are based on MATLAB Simulink which shows the system improvement in faulty conditions using this method.

中文翻译：

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具有不同负载的孤岛微电网中具有不同下垂增益的 DG 的新 LVRT 策略

摘要 低电压穿越 (LVRT) 是任何电力系统，特别是微电网的故障条件下的重要要求。当故障发生时，会产生过流和不平衡电压，从而导致微电网中基于逆变器的分布式发电机（DG）严重损坏。为了防止这种现象，许多类型的研究都被引导到限制故障条件下的电流，并改善和平衡 PCC 电压，使其没有任何失真。本文在故障发生期间注入无功功率的孤岛模式中，提出了LVRT方法。该无功功率被注入以补偿电压骤降并同时限制故障相中的过电流。同样使用这种方法，无故障的相位不会退化，也没有过电压。值得注意的是，本文中的两个逆变器假设具有不同的下垂增益，因此必须根据故障和无故障条件下的下垂增益来分配它们的电流和功率。仿真结果基于MATLAB Simulink，显示了使用该方法在故障条件下的系统改进。