电网电压对称跌落时无刷双馈风力发电机的状态反馈控制  

State Feedback Control of Brushless Doubly-Fed Wind Power Generator under Symmetrical Grid Voltage Drop

作　　者：聂鹏程 吴文辉 Nie Pengcheng;Wu Wenhui(Department of Electrical Machinery Huazhong University of Science and Technology,Wuhan 430074 China;EAST Group Limited by Share Ltd,Dongguan 523808 China)

机构地区：[1]华中科技大学电气与电子工程学院,武汉430074 [2]易事特集团股份有限公司,东莞523808

出　　处：《电工技术学报》2023年第17期4610-4620,共11页Transactions of China Electrotechnical Society

基　　金：东莞市引进创新科研团队计划资助项目(东科[2014]109)。

摘　　要：对于并网运行的无刷双馈风力发电系统,在电网电压瞬时对称跌落时,相当于在并网点突加一个反向电压源。采用传统双闭环PI控制策略时,通过在复频域推导功率绕组和控制绕组瞬态电流的表达式,得出其超调量和振荡时间受发电机参数、电网电压的跌落程度、相位及转速的影响。提出一种状态反馈控制策略,构建以功率绕组和控制绕组电流为状态变量的状态模型。通过反馈矩阵在输入端加入状态变量,改变了发电机系统矩阵的参数,即改变了发电机的等效参数。极点分布图显示状态反馈策略下极点较传统控制极点大幅左移,则系统加速收敛,同时减小了振幅,支撑系统故障过程平稳过渡。最后,通过额定工况下电网电压跌落至20%时的实验波形,验证了状态反馈控制的可行性。For the grid-connected wind power system with brushless doubly-fed generators(BDFG),the transient symmetrical drop of grid voltage is equivalent to a sudden impose of a reverse voltage source at the grid-connected point.As a matter of fact,there are some deficiencies in the current research on low voltage ride through of BDFG.To be specific,some literatures merely give theoretical research without optimization strategies,and in some other studies,the hardware equipment are installed to improve system performance,but it increased the system cost.What’s more,there are no comparative experiments carried out in the other works.On this basis,the dynamic operation characteristics of the BDFG under transient symmetrical voltage drop are deeply studied in this paper.Moreover,an optimal control strategy,i.e.,state feedback control,is proposed to improve the transient operation characteristics of the control system.Firstly,the simplified dynamic mathematical model of the BDFG after converting the rotor circuit is listed.Then,the steady-state current before the voltage drop as well as the transient current after the transient voltage drop are obtained.Afterwards,the current of the power winding(PW)and control winding(CW)after the transient voltage drop is solved by applying the superposition principle.It is observed from the results that the overshoots and oscillation time of the transient current are related to the generator parameters,the degree and phase of the voltage drop,as well as the rotor speed.However,the degree and the phase of grid voltage drop cannot be controlled for the operating wind power system with BDFG.Moreover,the generator speed could not change suddenly.In addition,the parameters of the generator is fixed after been manufactured.To improve the operation characteristics of the control system,the state model is further constructed regarding PW and CW current as state variables.Then,the state variables are added to the input through the feedback matrix.Therefore,the parameters of the generator system m

关 键 词：无刷双馈电机 风力发电 电网电压跌落 振荡超调 状态反馈 

分 类 号：TM315[电气工程—电机]