分散式风电场DFIG与SVC协调无功控制策略

Strategy of reactive power control for distributed wind farm operation using SVC and DFIG

针对具有动态无功调节能力的双馈风力发电机组组成的分散式风电场,提出了一种并联无功补偿方案,综合利用风电场安装的SVC无功补偿装置及双馈机组的无功调节能力来实现无功优化。由风电场电压控制点的电压偏差推算出风电场的无功功率需求,根据此时双馈风机和SVC无功补偿装置实际无功发生能力,以网损最小为目标函数进行无功分配,通过此分配方法既可以发挥双馈风机无功调节能力又可以减小风电场能的损耗。仿真结果表明采用所提策略能够充分发挥分散式风电场的快速无功调节能力,有效抑制风速扰动、负荷变化、电网故障等因素引起的电压波动,维持接入地区电网的电压稳定性。

For distributed wind farm consisting of DFIG with dynamic reactive power regulation, a parallel reactive power compensation scheme was proposed. To achieve the reactive power optimization, both SVC installed in wind farm and the reactive power adjustment ability of DFIG are used. The wind farm reactive power requirements from the relative voltage offset of the voltage control bus is obtained according to DFIG and SVC actual reactive power production ability to assign reactive power generating based on reducing generator losses. In steady state, two-level reactive power allocation can not only make full use of reactive power capability of DFIG driven wind turbines, but also reduce wind farm＇ s generator losses. Example shows that the proposed strategy can make full use of reactive power regulating ability of distributed wind farm to restrain voltage fluctuation caused by disturbances such as wind speed or load variation and maintain voltage stability in interconnected regional power grid.