I- Introduction

II- Wind Turbine Configuration

III- Proposed Control System With the Higher Order Super-Twisting Sliding Mode Control

IV- Conventional and Proposed Inertial Power Based HC Methods

V- Experimental Results and Discussion

VI- CONCLUSION

References

ABSTRACT

Finding and tracking maximum power point are two important dynamics in the control of variable speed wind turbines, since they determine the efficiency of wind turbines. The conventional hill climbing possesses the problems of wrong directionality and low performance, since it does not take the inertial effect into account. In this study, a novel hill climbing method is proposed by considering the inertial effect to solve these problems. Besides, employing the exact model knowledge of the generator in the maximum power tracking control deteriorates the efficiency considerably, therefore it is required to design a parameter independent and robust control system if possible. Thus, the third order super twisting sliding mode and continuous integral sliding mode controllers are designed for the control of generator and grid side converters to track the maximum power trajectory accurately, and they are compared to each other for the chattering in experimental results. A comparison is also performed between the conventional and proposed hill climbing methods based on the captured energy from the wind. Experimental results, with a wind turbine emulator, demonstrate that the proposed hill climbing method relaxes the wrong directionality and sluggish performance of the conventional one.

NTRODUCTION

wing to the intermittent characteristic of wind, maximum power tracking is an imperative requirement to increase the efficiency of the wind turbines. To this aim, Variable Speed Wind Turbines (VSWTs) have been developed to increase the efficiency in comparison with constant speed wind turbines [1]. Maximum Power Point Tracking (MPPT) is achieved by adapting the turbine speed optimally below rated wind speed. Two important dynamics arise when the MPPT based control of VSWTs is the subject, these are the instantaneous detection and tracking of the Maximum Power Point (MPP). In the literature, there are widely used MPPT methods based on Generator Signal Feedback (GSF), Tip Speed Ratio (TSR), Optimal Torque Control (OTC), Wind Turbine Power Curves (WTPC) and Hill Climbing (HC) [47].