考虑多无功源的光伏电站两阶段无功电压协调控制策略

在综合考虑各种无功源调节性能基础上,提出了一种综合利用静止无功发生器、光伏逆变器和电容器组的光伏电站无功电压协调控制策略,其包含两个控制阶段:第一阶段为考虑多无功源的协调电压控制,最大化利用站内无功源,在减少电容器组投切次数的同时,快速响应系统无功变化,维持公共连接点电压稳定;第二阶段为动态无功优化控制,利用动态无功(静止无功发生器)与静态无功(电容器组)、快速无功(静止无功发生器)与慢速无功(光伏逆变器)的无功代替,使静止无功发生器保留足够的无功裕度,提高电网应对电压崩溃的能力。最后,将所提出的无功电压控制策略应用到实际光伏电站中,验证了该策略的有效性。

Two-stage Reactive Power and Voltage Coordinated Control Strategy for Photovoltaic Power Station Considering Multiple Reactive Power Sources

Considering the regulating performance of multiple reactive power sources, a reactive power and voltage coordinated control strategy which comprehensively utilizes the static var generator(SVG), photovoltaic inverters and capacitors is presented, with two control stages involved. The first stage is coordinated voltage control considering multiple reactive power sources, which maximizes the use of reactive power sources, so as to reduce switching frequency of capacitors, and quickly responds to the change in system reactive power, while maintaining voltage stability at the point of common coupling. The second stage consists in dynamic reactive power optimization control, through the replacement of dynamic reactive power(static var generator)with static reactive power(capacitors), and fast reactive power(static var generator)with slow reactive power(photovoltaic inverters). The SVG retains sufficient reactive margin, to make the power grid more capable of surmounting the problem of voltage collapse. Finally, the reactive power and voltage control strategy is applied in actual photovoltaic power stations to verify the strategy.