摘要
基于STATCOM和DFIG的数学模型研究与控制器建模,提出一种由两者共同参与的风电场无功电压控制方案。该方案利用STATCOM的电压控制模式,并充分考虑到双馈风机的无功调控能力,将双馈风机集群电压控制分为无功需求决策层和无功协调优化分配层。此外,针对风电场出口发生三相短路的紧急状况,提出一种故障时双馈风力发电机组的改进控制策略,该策略通过故障时将转子侧变流器由功率控制模式切换为电压控制模式,有功电流优先切换为无功电流优先,网侧变流器由单位功率因数运行切换为极限无功功率运行的方式提高风电场的低电压穿越能力。仿真表明,该方案不仅能实现正常运行时对风电场并网点电压指令的快速跟踪,风速、系统负荷和系统电压波动时快速稳定风电场并网点电压,而且当风电场出口发生短路故障时,能显著减小故障对双馈风机的不利影响,加速故障后电压恢复。
A scheme of reactive power and voltage control including STATCOM and DFIG in wind farm is proposed basing on research on their mathematical and control model respectively. The scheme makes use of the voltage control mode of STATCOM and divides the voltage control of DFIGs into reactive power demand calculation and reactive power allocation, considering the reactive power control capability of DFIG. In addition, a control strategy for the emergency of three-phase short-circuit on wind farm PCC is proposed. The strategy can improve LVRT capability of the wind farm by means of switching reactive power control to voltage control, active current priority to reactive current priority of rotor side converter, unity power factor to maximum reactive power of grid side converter when fault occurs. Simulation results show that the scheme can not only achieve the fast tracking of voltage command of wind farm PCC, quickly stabilizing the voltage when wind speed, system load and system voltage fluctuates, but also can significantly reduce adverse effects on DFIG when the PCC fault occurs and speed up voltage recovery after fault.
出处
《陕西电力》
2012年第11期20-25,37,共7页
Shanxi Electric Power
基金
国家自然基金项目(51077049)
国家自然基金重大项目(51190103)
北京市科技新星计划
"111"引智计划(B08013)
