Voltage control of a stand alone hybrid system using fuzzy logic controller

Many countries have been faced with danger of energy shortage and many environmentalists have been worried about global warming due effect of CO2 emissions. Furthermore, lack of saving in electrical resources added severe of crisis in these countries. Moreover, many remote areas don't have access to grid. Most of power systems experience a transient mode. In a special case, the operation of solar panel and wind turbine is depended to solar irradiance and wind speed. Also, maintenance DC-link voltage and output AC voltage regardless variations of wind speed and solar irradiation can be a challenging topic. In this thesis, a new strategy based on the stability of DC-bus voltage for a hybrid power system is proposed. Firstly, the operation of DC-bus voltage for a stand-alone hybrid power system consists of solar panel and wind turbine is investigated. In this case, a PI controller is used to regulating at its reference value. Then, the performance of DC-link voltage in a stand-alone hybrid system included a solar PV, wind turbine, battery and the fuel cell is studied. Furthermore, the Fuzzy logic controller is used as a power management energy in this case. Finally, the performance of DC-link voltage in a stand-alone hybrid system under PV system is out of service and when 50% of load is used is studied. The MATLAB/Simulink and SimPowerSystems software packages are used to model a proposed stand-alone hybrid power system. Simulation results show that proposed strategy has better performance under fast variation of irradiance. The first chapter contains literature review. This chapter addresses articles pertaining to design and improve the voltage control algorithm in the power system. In the second chapter, hybrid power system is introduced and the importance of using it in the network to improve the control of the power system is explained. The third chapter describes the componenet mathematic and matlab modeling. The renewable energy conversion systems are used to harvest generated energy in DC busbar and then converted to AC by a three-phase full-bridge inverter. The proposed distributed generation substructure supplies loads with low total harmonic distortion. A new strategy based on stability of DC-bus voltage for a stand alone hybrid power system is proposed in Chapter 4. Finaly the results of Simulink discussed in the fifth chapter.