DFIG接入单机无穷大系统的阻尼转矩简化计算

Simplified Calculation of Damping Torque of Single-machine Infinite-bus Power System Connected with DFIG

建立了双馈风力发电机各个部分的数学模型并简化,进而得出了双馈风机接入单机无穷大系统后的线性化模型。根据该线性化模型画出相应的Phillips-Heffron模型图。对于双馈风力发电机接入单机无穷大系统的情况,同步发电机的机电振荡回路受到的阻尼转矩来自两部分:一部分来自于同步发电机的励磁绕组及自动电压控制器(AVR),另一部分来自于双馈风机。结合Phillips-Heffron模型图,得到同步机的励磁部分和双馈风机部分对机电振荡回路提供的阻尼转矩的完整算法。然后根据Phillips-Heffron模型图,对双馈风机部分提供的阻尼转矩进行简化分析,并提出两种简化方法。最后通过算例对所提阻尼转矩简化算法进行验证。结果表明,两种简化算法与完整算法结果相近,验证了简化的合理性。

The mathematical model of each part of Doubly Fed Induction Generator（ DFIG） is given and simplified,and the linear model of single-machine infinite-bus power system connected with DFIG is derived. According to the linear model,the figure of Phillips-Heffron model can be drawn. For single-machine infinite-bus power system with connected DFIG,the damping torque of electromechanical oscillating circuit of synchronous generator can be divided into two parts： one part is synchronous generator＇s excitation winding and automatic voltage controller（ AVR）,the other part is DFIG. Integrity algorithm of the damping torque to the electromechanical oscillating circuit which is from excitation of synchronous generator and DFIG individually can be derived by using the figure of Phillips-Heffron model.Then,according to the figure of Phillips-Heffron model,the paper simplifies the damping torque from DFIG and proposes two simplified algorithms. Finally,DTA is validated by an example. Results of these two simplified methods are close to results of integrity algorithm,which verifies the rationality of simplification.