Research On Control Strategy For Doubly Salient Electrical-magnet Direct-driven Wind Power Generator And Wind Turbine Emulator System

The development and utilization of wind power is considered as an important part of sustainabledevelopment strategies both at home and abroad due to the energy crisis and environmental pollution.Direct-driven wind power generation system is considered to be an important research direction inwind power generation technology aera due to its simple mechanical parts, high reliability, etc.Firstly, this paper introduces the research status and trends of direct-driven wind power generatorand its control strategy, and then describes the developments of doubly salient electrical-magnetmachine (DSEM) in the wind power genenration system and wind turbine emulator (WTE). A newdoubly salient electrical-magnet direct-driven wind power generator system is proposed. Its generatorhas advantages of high reliability, low cost and flexible control of excitation current, which meets thetrend of direct-driven wind power generation system.In this paper, the operation principles of wind turbine are introduced, the tip speed ratio (TSR)control method and the power signal feedback (PSF) control method are analyzed theoretically. Then,two control strategies specially designed for doubly salient electrical-magnet generator (DSEG) areproposed. Excitation current is regulated to control the electromagnetic torque of DSEG, which inturn makes DSEG work at constant output voltage mode or maximum power point tracking (MPPT)mode. Simulation models are carried out with MATLAB based on the control strategies. The resultsof simulation demonstrate the feasibility of control strategies proposed in this paper.By analyzing the characteristics of wind turbine, we note that the dynamic characteristic of afixed-pitch wind turbine could be realized with real-time torque compensation proportional to thespeed acceleration of shaft. A wind turbine emulator is established based on LabVIEW. At last, theexperiments of wind turbine characteristics are tested under different wind speed. The results verifythe imitation scheme of wind turbine characteristics.Finally, a generator control engineering prototype based on DSP and CPLD digital control isbuilt and the hardware and software designs are introduced. The experimental results based on theprototype and a10kW48/32DSEG, show the correctness of the theoretical analysis and simulationresults and demonstrate the effectiveness of control strategies proposed in this paper.