摘要
电网故障时风电系统的Crowbar装置能够帮助风电机组实现低电压穿越,然而Crowbar的投入使得双馈风电机组要从电网吸收无功功率,延缓电网电压重建的过程。因此,需要在故障时对风电场进行无功补偿。针对这个问题,提出一种新型无功协调控制策略,在电网电压跌落后,根据并网点电压水平以及Crowbar的动作情况,整定风电场的无功调节需求,通过两层无功分配策略,协调双馈风机和STATCOM对电网进行无功补偿,用以支撑风电场并网点电压。采用这种控制策略,不仅可以提高风电机组的低压穿越能力,也减少了无功补偿装置的投入容量,仿真分析验证了所提策略的可行性和有效性。
The wind power system with Crowbar can achieve low voltage ride through during the grid fault.However,Crowbar makes the double-fed wind turbine absorb reactive power from the grid,delaying the process of rebuilding the grid voltage.It means the reactive power compensation is required.A new reactive power coordinated control strategy which supports the voltage level of point of common coupling（PCC） was proposed.By this scheme,the reactive power demand of the wind farm was calculated according to the voltage level of PCC and the action of Crowbar protection during the fault.Through two layers of reactive power allocation strategy,DFIG（Doubly Fed Induction Generator） and STATCOM were coordinated to compensate the reactive power to the grid.This control strategy not only improves the low voltage ride through capability of the wind turbines,but also reduces the inputs of reactive power compensation devices.The simulation of a practical example verifies the feasibility and efficiency of the proposed scheme.
出处
《电机与控制学报》
EI
CSCD
北大核心
2014年第6期50-54,60,共6页
Electric Machines and Control
基金
国家863计划项目(2011AA05A105)
关键词
故障
协调控制
无功补偿
双馈感应发电机
CROWBAR
静止无功补偿器
fault
coordinated control
reactive power compensation
doubly fed induction generator
crowbar
static synchronous compensator
