同步发电机的非线性鲁棒电压控制

Nonlinear Robust Voltage Control for Synchronous Generators

提出了一种同步发电机非线性鲁棒电压控制器设计方法,解决了目前多数非线性励磁控制方法依赖于系统的特定运行点并且难以考虑电压调节精度的局限。针对发电机经变压器接入电力系统的数学模型,将其转换为以机端电压偏差、角速度偏差和有功功率偏差为状态变量的不确定线性系统,进而采用基于LMI的鲁棒控制理论设计出非线性电压控制器。与现有的非线性励磁控制器相比,所提出的电压控制器不依赖于系统的特定运行点,能适应网络参数与运行方式变化,实现机端电压调节功能。控制器对模型干扰有强鲁棒性,无须针对单机无穷大系统和多机电力系统分别设计。此外,控制器无须测量发电机转子角及任何变量的微分与积分。利用PSCAD/EMTDC对某单机无穷大系统及WSCC四机系统分别测试,仿真结果验证了控制器的良好性能。

Most nonlinear excitation control methods depend on the operating point of power system and can＇t assure voltage regulation accuracy of synchronous generators. For this reason, a nonlinear robust voltage control strategy is proposed in this paper. For a synchronous generator connected to power network through a transformer, the mathematical model is transformed into a uncertain linear system with the state variables of deviations of generator terminal voltage, rotor speed and generator active power output. And then a nonlinear voltage controller is designed utilizing a linear matrix inequation（LMI） based robust control theory. Compared with the existing controllers, the proposed controller assures voltage regulation accuracy and adapts to system parameters and operating points. And the controller doesn＇t need to be respectively designed for single-machine-infinite-bus system and multi-machine power system. Besides that, neither rotor angle nor any variable＇s differentiation or integration needs to be measured for the controller. Detailed tests were conducted by PSCAD/EMTDC for a single-machine-infinite-bus system and WSCC 4-machine power system respectively, and simulation results illustrate good performance of the proposed controller.