A simulation study of hybrid wind-ultracapacitor energy conversion system

Wind energy conversion system (WECS) is controlled to capture the maximum available power upon the available wind speed to make the system economical and operates at optimized efficiency. The nature characteristic of wind generator is nonlinear which leads to variable power output generation. In addition, the demanded load power is subjected to a change due to any disturbances may happen in the load voltage or current. Therefore, it is essential to integrate the WECS with a suitable storage element to either, act as a source of compensating the inadequate in power, or act as a load to absorb the excess power generated by the wind generator. Although the AC rectified voltage of the wind generator is proportional to the wind speed which is variable, however, the DC-bus voltage is usually regulated by the bidirectional converter at a specified value. Hence, the output power of the system can be investigated by means of the output currents from the WECS and the ultracapacitor. This paper presents several different test scenarios of the proposed hybrid WECS-ultracapacitor simulated using MATLAB/Simulink software. It also highlights the important role of the ultracapacitor in ensuring a continuous power flow.