可变速抽蓄机组与直驱风电机组联合运行系统的小信号稳定分析

Small-signal stability analysis of combined operation system of variable-speed pumped storage unit and direct-drive wind turbine unit

可变速抽蓄机组与直驱风电机组联合运行系统含有大量电力电子装置,将引发系统稳定性问题。对此,基于水泵水轮机刚性管道模型与两电平变流器的平均值模型,在同步旋转dq0坐标系下,建立了二者交流并网联合运行系统的详细数学模型,采用特征值法进行系统的小信号稳定分析,并基于参与因子分析得到了影响不同振荡模态的相应参数,并进一步根据系统特征根轨迹,研究了不同工况下系统电气参数、控制器锁相环参数以及控制器比例积分参数变化对系统稳定性的影响规律。结果表明,水泵工况快速转速控制方式系统的稳定性受电气侧参数影响更大;可变速抽蓄机组锁相环阻尼比的减小会增大直驱风电机组锁相环阻尼比的稳定域;可变速抽蓄机组功率控制器积分参数与直驱风电机组直流电压控制器积分参数存在耦合。

The combined operation system of variable-speed pumped storage unit and direct-drive wind turbine unit contains a large number of power electronic devices,which will cause certain system stability problems.In this regard,based on the rigid pipeline model of pump turbine and the average value model of twolevel converter,in the synchronous rotating dq0 coordinate system,a detailed mathematical model for the two parts under AC-grid-connected combined operation system is established,and the eigenvalue method is used for the small-signal stability analysis of system,and based on the participation factor analysis,the corresponding parameters that affect different oscillation modes are obtained.According to the characteristic root locus of the system,the influence law of the electrical parameters of the system,the phase locked loop parameters of the controller and the PI parameters of the controller on the system stability under different working conditions is further studied.The results show that the system stability of the fast speed control mode of the pump working condition is more affected by the electrical side parameters,the decrease of the phase locked loop damping ratio of the variable-speed pumped storage unit will increase the stability range of the phase locked loop damping ratio of the direct-drive wind turbine unit,and there is a coupling between the integral parameters in power controller of variable-speed pumped storage unit and the integral parameters in DC voltage controller of direct-drive wind turbine unit.