双馈风机虚拟惯量控制策略研究

Study on virtual inertia control strategy of doubly fed wind turbine

双馈风机由于其转子转速不能像传统同步机一样保持与电网频率的一致性,导致风机的机械惯性不能参与电网频率调节。针对常规虚拟惯量控制策略通过释放转子"隐藏"的动能,为电网提供转动惯量,参与频率调节,但只能为电网提供短暂的频率支撑,频率恢复过程中,还有可能导致频率二次下跌的问题。文章提出了利用储能系统协同风电场为电网补偿惯量的控制策略,在Matlab/simulink中搭建仿真模型,仿真结果表明,在电网负荷发生突变时,虚拟惯量协同控制策略能够为电网提供较长时间的频率支撑,并有效防止频率二次下跌,提高电网频率稳定性。

For the rotor speed of DFIG can not be the same as conventional synchronous machine consistent with the grid frequency, the mechanical inertia of wind turbines cannot participate in grid frequency regulation. The conventional virtual inertia control strategy releases the ＂hidden＂ kinetic energy of the rotor and provides the short-term inertia for the grid to participates in the frequency adjustment. In the process of frequency recovery, the frequency may drop secondary.This paper proposes a control strategy aiming at making use of the energy storage system to cooperate with the wind farm to compensate the inertia of the grid. The simulation model is built in Matlab/Simulink software and the simulation results show that the virtual inertia cooperative control strategy can effectively provide a long time frequency support for the grid when the grid load is abrupt and prevent the frequency secondary drop and improve the frequency stability of the grid.