Abstract:

A new micro hydro power generation (MHPG) scheme is proposed for supplying loads located at remote areas far away from grid. This paper presents three major contributions for small scale renewable hydro power generation technology. Firstly, the proposed model uses unregulated flow rates for two different generators for generating small scale hydroelectricity which otherwise generally uses constant flow rates. Secondly, a new architecture of converter is designed and implemented for parallel operation of two variable speed generators. Thirdly, a fuzzy PI based converter control is designed for the proposed MHPG system, which is found to perform better than that of conventional PI control based systems. In this, a new architecture of AC-DC-AC converter is used for controlling two parallel operated variable speed Capacitor Excited Asynchronous Generators (CAGs). The two CAGs are considered to be operated at variable speeds as fed by two different variable turbines. The converter system consists of two numbers of two level voltage source converters (VSCs) and one common voltage source inverter (VSI). The control algorithms are appropriately designed so as to manage the variable inputs by converting each of the generated variable ac voltages to dc voltage at a common dc bus. The VSI provides constant voltage and frequency at the load end. This architecture eliminates the problem of synchronization of two variable sources and also optimizes the cost and components required compared to that of system using individual back to back converters for each generating units. The proposed scheme is investigated and analysed to assess the feasibility in terms of its performance and quality of power under different loads such as resistive and inductive loads. Firstly, the switching frequency and modulation index for the converter are determined for giving efficient performance. Finally, the performance of the proposed fuzzy PI controlled converter based MHPG and that of conventional PI controlled converter system is compared and presented. The modeling and the simulation are carried out in MATLAB/Simulink environment.<

Keywords: