This article presents a dynamic voltage support (DVS) scheme for achieving low-voltage ride-through (LVRT) with a grid-connected photovoltaic (PV) inverter during the voltage sag fault. The DVS scheme is achieved by formulating an additional reactive active current control mode which is developed from a conventional reactive current control approach. This provides stable operation of the system and achieves higher effectiveness due to the lower X/R ratio at the point of common coupling in low-voltage networks. Further, the performance of the proposed controller is assessed by simulating a 4 kW system for voltage sag faults. Further, the proposed controller tested with the real-time simulations and experimental setup for voltage sag conditions. The results presented demonstrate that the active and reactive power is regulated in concordance with grid code requirements. The controller achieves LVRT within the time limits of grid standard during symmetrical faults, which makes it appropriate for fast transient events. This operates the PV system under its nominal capacity, avoiding unwanted grid disconnection events.

中文翻译：

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动态电压支持单相并网光伏系统中的低压穿越操作


本文提出了一种动态电压支持 (DVS) 方案，用于在电压暂降故障期间通过并网光伏 (PV) 逆变器实现低压穿越 (LVRT)。 DVS方案是通过制定从传统无功电流控制方法发展而来的附加无功有功电流控制模式来实现的。由于低压网络中公共耦合点的 X/R 比较低，因此系统可以稳定运行并实现更高的效率。此外，通过模拟 4 kW 系统的电压暂降故障来评估所提出的控制器的性能。此外，所提出的控制器通过电压暂降条件的实时模拟和实验装置进行了测试。结果表明，有功功率和无功功率的调节符合电网规范要求。该控制器在对称故障期间在电网标准的时间限制内实现低电压穿越，这使得它适合快速瞬变事件。这使得光伏系统在其标称容量下运行，避免了不必要的电网断开事件。