储能型双馈风电场联合STATCOM的无功协调控制

针对传统双馈风电机组(DFIG)低电压穿越(LVRT)能力不足问题，提出了储能型双馈风电场联合STATCOM的无功协调控制。该控制是在网侧变流器（GSC）原有的模型上将超级电容经隔离型DC/DC变换器并联到风机直流侧，以此吸收故障期间直流侧产生的不平衡功率；在发生低电压故障时，根据超级电容投入情况，对两侧变流器和并联在风机出口母线上的STATCOM进行无功协调控制来支撑电网电压；同时超级电容储能装置采用电压电流双闭环控制，满足了系统稳定性和经济性的要求。仿真结果表明：该方法应用在风电并网系统中可以使DFIG的LVRT能力得到极大的提升。

Coordinated Reactive Power Control of Energy Storage Doubly-Fed Wind Farm Combined with STATCOM

The low voltage ride through (LVRT) capability of traditional doubly-fed induction generator (DFIG) is insufficient. To solve this problem, the coordinated reactive power control of energy storage type doubly-fed wind farm combined with static compensator (STATCOM) is proposed. The control is based on the original model of the DFIG, and connects the super capacitor in parallel to the DC side of the wind turbine via an isolated DC/DC converter. As a result, the control can absorb the unbalanced power generated on the DC side during the fault. In the event of a low voltage failure, according to the input of super capacitor, coordinated reactive power control performs on the converter on both sides and the STATCOM connected in parallel on the outlet bus of the wind turbine to support the grid voltage. At the same time, the super capacitor energy storage device adopts voltage and current double-closed-loop control, which can meet the requirements of system stability and economy. Simulation results show that the proposed control in the wind power grid-connected system can greatly improve LVRT capability of DFIG.