A Maximum Wind-energy Capture Method Based on Sliding Mode Inverse Decoupling Control for Small Permanent Magnet Direct-drive Wind Turbine

Abstract

Small wind power generation systems have the characteristics of nonlinear strong coupling and the application requirements of small weight and low cost. If the traditional blade tip speed ratio method is used for the maximum wind energy capture control of wind turbine, there is a problem of poor dynamic performance when wind speed changes. This paper proposes a maximum wind energy capture method based on an inverse system, which takes the permanent magnet synchronous generator (PMSG) as the object, and introduces a method of inverse system to linearly compensate the original system. This method needs to observe rotor angle, speed and mechanical torque of PMSG. Conventional mechanical sensors will increase the weight, volume and design cost of small wind power generation system, while traditional sensorless technologies such as sliding mode observer have their own problems of large vibration. To solve this problems, an improved sliding mode observer is designed for the proposed method. Simulation results show that the proposed control method has better dynamic decoupling performance than the traditional one, and the improved sliding mode observer can eliminate its own jitter to a great extent, and can achieve accurate observation of PMSG rotor angle, speed and mechanical torque in the full speed range.

Keywords

• permanent magnet synchronous generator(pmsg)
• inverse system
• sliding mode observer
• sigmoid function
• maximum wind-energy capture