Design Of HIL Simulation System For Permanent Magnet Direct-drive Wind Power Generation System

Wind power as a clean energy has been widely used in recent years. With the rapid growth of the wind power penetration in local power grid, the effect on the stability of the power grid caused by operating characteristics of the wind power begins to appear. Effective wind power system control strategy guarantee the stabil-ity of power grid and wind power generation system. At present, the strategies of the wind power system are developed by the pure digital simulation software, it can't simulate the real operating characteristics of controller and isn't convenient to verify a new control algorithm. For these reasons, this paper sets up a hardware-in-loop simulation system of the permanent magnet direct-drive wind turbine.Firstly, according to the requirements analysis, the overall design of the hard-ware in the loop simulation system has been given in this article, then the overall plan of hardware and software for controller also has been designed. Finally, the paper has made the hardware chip selection.Secondly, this paper introduces the mathematical models of the wind turbine and the permanent magnet synchronous generator. The mathematical models of the wind speed, wind turbine and the permanent magnet synchronous generator are analyzed in detail which provides the basis for the improvement of wind power sys-tem control strategy.Again, according to the characteristics of the permanent magnet direct-drive wind power generation system, the machine side converter and grid side converter control strategy are designed. The machine side converter adopts the mountain climbing method to realize Maximum Power Point Tracking and adopts vector con-trol strategy based on the zero d shaft current of the rotor flux to realize the de-coupling control of active power and reactive power; The grid side converter adopts double closed loop control strategy based on grid voltage orientation to realize the interconnection. Moreover, according to the characteristics of three-phase symmetric zero voltage drop, this paper use the strategy of using unloading resistance to con-sume the unbalance energy on either side of capacitance.Then, according to the requirements, the design of its hardware and software has been carried on. Circuits of the inverter controller is designed. As for the soft-ware design, the main power circuit real-time simulation model in the improvement of the permanent magnet direct-drive wind power system is constructed; Control program of converter controller is designed, including the main program, the inter-rupt subroutine program, double closed-loop control algorithm program, the phase-locked loop program, sample program, SVPWM modulation program.Finally, the platform has been built, on which hardware and software has been tested.The results and operation show that the permanent magnet direct-drive wind power system real-time simulation platform built in this paper can operated stably and verify quickly, the control strategy of wind power generation system, achieve the expected design goals.