Abstract. In order to solve the problem of maximum energy capture in the dynamic changing current, the maximum power point tracking (MPPT) control strategy of an extensible vertical-axis blade current power generation system was developed. Consider the current speed with the characteristics of randomness and uncertainties. Affixed set of PID parameters can hardly achieve desired generator speed. Therefore, this paper presents a Fuzzy-PID control, which combines the characteristics of traditional PID and fuzzy control. The simulation results show that the Fuzzy-PID control is able to guarantee desired dynamic characteristics, such as fast response, robustness and stability, and is able to effectively track the maximum power point.
IntroductionWith the high speed development of economy, global problems gradually change seriously, such as air pollution, resource shortage and ecological deterioration. In order to solve the energy crisis and air pollution effectively, development of new energy and the use the renewable energy to replace the non-renewable energy have become the trend [1]. The global ocean area is vast, which potential energy is enormous. The ocean current energy mainly includes the kinetic energy of water flow, which has many advantages in comparison to other renewable energy. The ocean current energy has strong regularity and stability, which are predictable. The ocean current generation device lies below sea level, which does not occupy the land area, would not affect the surrounding landscape and would not pollute the environment. Therefore, the development and utilization of the ocean current energy is connected by more and more people [2].