基于小交流信号的低压配电网中分布式光伏辅助调压控制策略

Distributed PV Auxiliary Voltage Control Strategy in Low Voltage Distribution Network Based on Small AC Signals

随着国内光伏产业不断发展,低压配电网中接入的分布式光伏电源的容量逐渐增多,当光照充足时配电网可能出现严重的过电压问题。分析了配电网中出现过电压现象的原因,针对配网的特点提出一种针对分布式光伏电源的辅助调压控制策略,旨在保证每台光伏电源的经济效益的同时充分发挥每台光伏电源的调压能力。所提出的控制策略在无功调节的基础上削减部分有功功率来调节电压,利用最大功率估计的方式实现光伏电源有功功率的削减控制,并通过向电网注入小交流信号来实现光伏电源间的通信和协调配合。最后算例结果验证了所提策略的有效性。

With the progress of China's photovoltaic industry,the capacity of distributed photovoltaic sources connected with the low-voltage distribution network is increasing.When the solar irradiance is high,the distribution network may suffer serious out-oflimit voltage.This paper analyzes the causes of out-of-limit voltage phenomenon in the distribution network,and an auxiliary voltage control strategy of distributed photovoltaic source is proposed for this problem.The purpose of the strategy is to ensure the economic benefits of each photovoltaic source while giving the best play to the voltage control ability of each photovoltaic source.The proposed control strategy reduces part of active power to control voltage based on reactive power control strategy.It uses the maximum power estimation method to realize the reduction control of active power of photovoltaic source,and realizes the communication and coordination between photovoltaic sources by injecting small AC voltage signal into the power grid.Finally,the validity of the proposed strategy is verified by case study results.