Tip Speed Ratio Based Maximum Power Tracking Control of Variable Speed Wind Turbines; A Comprehensive Design

Abstract

The most primitive control method of wind turbines used to generate electric energy from wind is the fixed speed control method. With this method, it is not possible that turbine input power is transferred to grid at maximum rate. For this reason, Maximum Power Tracking (MPT) schemes are proposed. In order to implement MPT, the propeller has to rotate at a different speed for every different wind speed. This situation has led MPT based systems to be called Variable Speed Wind Turbine (VSWT) systems. In VSWT systems, turbine input power can be transferred to grid at rates close to maximum power. When MPT based control of VSWT systems is the case, two important processes come into prominence. These are instantaneously determination and tracking of MPT point. In this study, using a Maximum Power Point Tracking (MPPT) method based on tip speed ratio, power available in wind is transferred into grid over a back to back converter at maximum rate via a VSWT system with permanent magnet synchronous generator (PMSG). Besides a physical wind turbine simulator is modelled and simulated. Results show that a time varying MPPT point is tracked with a high performance.

Keywords

• MPPT
• Wind Turbine