基于双馈风力发电机的次同步振荡及其抑制策略

双馈感应发电机(DFIG)也称双馈风力发电机,其变速恒频的优点在风电场中得到了广泛应用。随着大量风电能源并网,远距离高压输电使用串补电容技术容易引起电网发生次同步振荡(SSO)。DFIG的定子绕组直连电网,因此在运行过程中极易受到电网SSO的影响。针对DFIG的SSO及抑制策略进行研究。首先,建立了DFIG系统数学模型,分析DFIG系统的控制策略;接着,针对SSO采用一种改进的基于2阶广义积分器(SOGI)的锁相控制技术;然后,在转子侧变流器(RSC)采用准谐振控制器(QRC)抑制SSO对于定子输出的影响;最后,通过MATLAB/Simulink软件仿真,验证了控制方案的正确性和有效性。

Subsynchronous Oscillation Based on Doubly Fed Induction Generator and Suppression Strategy

Doubly fed induction generator (DFIG) is widely used in wind farms due to its advantages of variable speed and constant frequency.With a large number of wind power sources connected to the grid,the use of long-distance high-voltage transmission technology is likely to cause the risk of subsynchronous oscillation (SSO).The stator winding of DFIG is directly connected to the power grid,so it is very easily affected by the subsynchronous oscillation of the power grid in the operation process.This paper studies the subsynchronous oscillation and suppression strategy of DFIG.Firstly,this paper establishes the mathematical model of DFIG system,analyzes the control strategy of DFIG control system,then proposes an improved phase-locked control technique based on second-order generalized integrator (SOGI) for subsynchronous oscillation and compared with traditional phase-locked methods.Finally,a resonant control strategy is adopted in the rotor-side converter (RSC) to suppress the impact of subsynchronous oscillation on the stator output.The correctness and effectiveness of the control scheme is verified through Matlab/Simulink software simulation.