Advanced Materials Research Vol. 768

Abstract: Flexible AC transmission system (FACTS) is a system composed of static equipments used for ac transmission of electric energy to improve the power transfer capability and to enhance controllability of interconnected network. Unified Power Flow Controller (UPFC) is the most widely used FACTS device for providing fast acting reactive power compensation on high voltage electricity transmission network. This paper deals with the designing of Adaptive Neuro Fuzzy Inference controller (ANFIC) and fuzzy based Particle Swarm Optimization (PSO) controller for the performance analysis of UPFC. The controller have been designed and tested for controlling the real and reactive power of UPFC. Fuzzy-PI controller is used to control the shunt part of UPFC. The system response under high short circuit level is tested on 5-bus system and 118-bus system. Computer simulation by MATLAB/SIMULINK has been used to verify proposed control strategies.

Abstract: A new three input DC-DC boost converter fed symmetrical multilevel inverter is proposed. The converter interfaces two unidirectional input power ports and a bidirectional port to battery in a unified structure. This converter uses hybrid alternative energy source such as Photo Voltaic (PV) source, Fuel Cell (FC) source, and Battery. Supplying the output load, charging or discharging the battery can be made by the PV and the FC power sources individually or simultaneously. The proposed structure utilizes only four power switches that are independently controlled with four different duty ratios. Proposed inverter uses two cells for five level output. Boost converter provided hybrid sources to multilevel inverter. Here we promote inverter for attain a pure sinusoidal harmonics free ac application.Key Words-Photovoltaic/fuel cell (PV/FC)/battery hybrid power system, three-input dcdc boost converter.

Abstract: This paper discusses the design and simulation of pulse width modulated based circuit for induction melting application. This high frequency inverter topology have the practical advantages of energy saving, clean environment, high output power due to low switching losses, less electromagnetic noise and low total harmonic distortion. This two stage power converter has single phase full bridge rectifier, DC filter, zero voltage switching pulse width modulation controlled high frequency inverter. In this work, the steady state operation and control strategy of pulse width modulated high frequency inverter is analyzed. In order to achieve energy efficiency switching losses are reduced by operating the inverter above resonance frequency. Input side supply harmonics is also reduced using EMI filter. The simulation of the designed high frequency power supply is carried out at a frequency of 20 kHz using MATLAB simulink tool. Simulation results proof the energy saving due to reduction in switching losses of the presented control strategy and reduction in harmonic distortion of the presented power supply for induction heating load.