基于ADRC和模糊虚拟电阻的双馈水电转子侧变流器研究设计

Research and design of doubly-fed hydropower rotor-side converter based on ADRC and fuzzy virtual resistance

现如今我国的水力发电建设已经取得了巨大的成果,其中,双馈水轮发电机组的出现不仅可以实现变速恒频,而且可以在变化大的水头下运行在最优工况处。针对系统在实现变速恒频时,变流器采用PI控制器会使其调节时间长,超调量大并且在转子侧易产生较高的电流的特点,首先对变流器采用自抗扰控制并进行改进,从而提升控制精度;然后通过模糊控制的虚拟电阻来对转子过电流进行抑制;最后建立仿真模型,与常规PI控制进行对比。结果表明,改进的控制策略使其功率响应更快更稳定,在变速恒频过程中有更良好的动态响应,电网电压跌落有效抑制了转子侧过电流,加强了系统的稳定性。

Nowadays great achievements have been made in hydropower construction in China.Among them,the appearance of doubly-fed hydro-generator set can not only realize variable speed and constant frequency,but also operate at the optimal working condition under the water head with great changes.In view of the characteristics-that PI controller is used in the converter to achieve variable speed and constant frequency,which will lead to long adjustment time,large overshoot and easy to generate higher current on the rotor side,ADRC is adopted in the converter and improved to improve the control accuracy.Then,the rotor overcurrent is suppressed by the virtual resistance of fuzzy control.Finally,the simulation model is established and compared with the conventional PI control.The results show that the improved control strategy makes its power response faster and more stable,and has better dynamic response in the process of variable speed and constant frequency.The voltage drop of the power grid effectively suppresses the rotor side overcurrent and enhances the stability of the system.