Lingappa Jaklair - Electrical Engineering Department,University College of Engineering,Osmania University
Guduri Yesuratnam - Electrical Engineering Department,University College of Engineering,Osmania University,Hyderabad
Pannala Sarma - Electrical Engineering Department,Vasavi College of Engineering,Hyderabad

This paper deals with the problems related to power stability issues in the isolated wind-solar based renewable energy system. The stability issues in such system are produced mainly due to unbalanced loading, distortion of load current and intermittent nature of renewable energy sources. To overcome these problems, A voltage source converter (VSC) is used in proposed literature. The VSC is driven using a time domain-based signal decomposition algorithm consisting a ۳-phase dual reduced order generalized integrators frequency Locked loop (DROGI-FLL). The ۳ phase DROGI FLL has the inherent abilities of noise rejection and error tracking, which improves the system stability and maintains the voltage and frequency of the system constant under transient conditions. The transient conditions are simulated by varying the loading condition, solar irradiance and wind speed in the system. Apart from stability issues this system also deals with the issues related to reactive composition, natural current compensation and operation of SPV system at maximum power point (MPP). A perturb and observe (P&O) maximum power point tracking (MPPT) is employed for the working of solar photovoltaic systems (SPV) system at MPP and to maximize the utilization of renewable energy. The neutral current compensation is achieved by using a star-double delta transformer.  This entire system is developed and tested in the MATLAB/SIMULINK environment.

voltage source converter, Power Quality, DROGI-FLL, Time domain-based signal decomposition, Wind-solar energy system, Load balance, Demand Response