Application Of LPV Gain Scheduling Control In Variable-speed Variable-pitch Wind Turbines

Wind power generation technology is the fastest improving green energy technology in the world,which has a good applicationprospect.Compared with other energy technologies,wind power generation technology has avantages of low cost and little environmental impact.The development and utilization of wind energy is of great significance for alleviating energy shortage and reducing environmental pollution.Optimizing the performance of wind energy conversion systems(WECSs)and increasing their work efficiency are important means of making full use of wind energy.Variable-speed variable-pitch wind energy conversion systems are highly nonlinear time-varying systems.As a common method of controlling nonlinear time-varying systems,traditional gain scheduling methods have some shortcomings in the application process-not only time-consuming and laborious,but also the designed controller cannot guarantee the performance of the system in the whole operating area.In order to improve this situation,the LPV gain scheduling control methods are used to design the controller of variable speed pitch wind energy conversion system.The LPV model is established,and the induced L2-norm is used as the performance measurement.As for the design method,the parameter-dependent H∞ robust control is adopted so that the gain of the controller can be adjusted in real time according to the change of parameters,which not only simplifies the design method but also ensures the performance of the system in the entire operating area.By using the theorems,the controller design problem is transformed into the linear matrix inequality(LMI)solution in this paper.Due to the continuity of parameters,LMI has an infinite number of solutions.In order to solve this problem,the concept of multiple cell type is introduced,and controllers are designed for each vertex individually,and then the controller of the whole system can be obtained by linear combination,so that only a limited number LMI have to be solved.Finally,taking the doubly-fed wind turbine as an example,the controller is designed based on LPV gain scheduling control at low wind speeds.The experimental results show that the speed of wind driven generator can follow the wind speed easily,at the same time,the energy capture is maximized,so as to achieve the control purpose.