Cost-effective high-reliability power-conditioning system used for grid integration of variable-speed wind turbine

This paper presents the development of a simple, high reliable and cost-effective wind power grid integration system which consists of a wind turbine emulator and an 1.5 kW Interior Permanent Magnet Synchronous Generator (IPMSG) with a power electronic interface for grid integration of a variable-speed wind turbine. The wind turbine emulator is realized by using an Interior Permanent Magnet Synchronous Motor (IPMSM) interfaced a high performance 2.1 kW inverter with torque control. Wind speed can simply be measured from the rectified output voltage of the generator-side 12 pulse diode rectifier to realize the developed algorithm of controlling the active current of the grid-side inverter for maximizing the output power of the wind turbine. The grid-side inverter is connected to the grid via an Inductor-Capacitor-Inductor (LCL) filter and the proposed control strategy for the grid-side inverter provides the highest capabilities of attenuating switching frequency components and damping the resonance. The developed algorithms of both finite-time settling grid integrated current control and Maximum Power Point Tracking (MPPT) control are implemented by a low-cost, high-performance digital signal processing (DSP) controller. The proposed system was tested and the power responses, torque responses and frequency responses confirm that the system can perform satisfactorily under step change of wind speed.