Research And Implementation Of Independent Experimental Platform For Wind Turbine With PMSG

With the extensive use of fossil fuels, non-renewable energy reserves on earth are dwindling. So people try to find renewable energy sources as a substitute for fossil energy, such as solar, wind, hydro, nuclear, biomass, etc., wind energy has got widely developed and used because of its'huge reserves, wide distribution and cleanness. It's difficult to rely on the actual wind environment when doing early studies for wind power generation technology in laboratory, therefore, establishing an experimental platform of wind power generation is significant. The experimental platform can help to reduce research costs and shorten the research time, and accelerate the development of wind power technology.Firstly, working principle and technology status of experimental platform for wind power generation are introduced, several commonly used experimental platform are compared and analyzed. On this basis, the structure of an off-grid experimental platform for wind power generation is decided. An induction motor and permanent magnet synchronous generator (PMSG) are respectively adopted as the imitation motor of wind turbine and generator. Through the control of converter, power supply for 220V/50Hz optional AC load is finally realized.Secondly, Strengths and weaknesses of commonly used asynchronous motor control strategies: vector control and direct torque control are compared and analyzed. Fuzzy control and neural network are introduced to traditional direct torque control strategy. A fuzzy controller and neural network stator flux observer are used to take place of the traditional hysteresis comparator and u-i/i-n/u-n stator flux observer. So that the intelligent direct torque control of asynchronous motor and the purpose of accurately wind turbine torque imitation are realized.Finally, on the basis of decided platform structure, hardware design based on DSP320F2812 is realized. Mainly including two parts: wind turbine imitation sub-system and off-grid generation sub-system. The former mainly figures out the sampling circuits for DC bus voltage and stator current, optocoupler isolation circuit,device selection for converter, algorithms involved in intelligent DTC and its DSP realization. The latter mainly figures out the main circuit topology, device selection of the experimental platform and software design for the control strategy.Simulation and experimental results verify that the system has achieved the desired task and the intelligent Direct Torque Control strategy can effectively reduce flux and torque ripple, so it's suitable for low-speed wind power systems with PMSG.