考虑光伏逆变器电流裕度的主动配电网动态电压支撑策略

大量分布式光伏接入配电网的电压稳定问题是影响电网安全稳定运行的关键环节。为了适应高渗透率分布式光伏发电系统的接入,提高主动配电网的动态电压支撑能力,提出了一种考虑光伏逆变器电流裕度的主动配电网动态电压支撑策略。该策略在分析配电网电压灵敏度的基础上,考虑光伏逆变器的电流设计裕度,能够在电压跌落故障情况下充分利用光伏逆变器的最大允许电流,实现光伏逆变器有功功率输出最大化,从而提高主动配电网的短期电压稳定性。最后分析了逆变器电流裕度对静止无功补偿系统的影响,并与常规无功补偿系统进行了仿真对比分析,验证了所提出策略的可行性和有效性。

Dynamic voltage support strategy for an active distribution network considering the current margin of a photovoltaic inverter

The voltage stability problem of a large number of distributed photovoltaics connected to distribution network is the key issue affecting the safe and stable operation of a power grid.In order to adapt to the access of a high permeability distributed photovoltaic power generation system and improve the dynamic voltage support capability of an active distribution network,a dynamic voltage support strategy for an active distribution network considering the current margin of photovoltaic inverters is proposed.Analyzing the voltage sensitivity of the distribution network,and considering the current design margin of photovoltaic inverters,the strategy can make full use of the maximum allowable current of photovoltaic inverters under a voltage sag fault to maximize the active power output of photovoltaic inverters,thereby improving the short-term voltage stability of the active distribution network.Finally,the influence of the current margin of the inverters on the static var compensation system is analyzed and compared with conventional reactive power compensation systems.The comparison verifies the feasibility and effectiveness of the proposed strategy.