2018 International Conference on Smart Electric Drives and Power System (ICSEDPS), 2018
Power quality related issues are one of major concern in the present time. The most frequent powe... more Power quality related issues are one of major concern in the present time. The most frequent power quality related problems are voltage sag. To protect sensitive load from voltage sags in the network, a power electronic based device named Dynamic Voltage Restorer (DVR) is installed between the supply side and the sensitive load side. Its basic purpose is to maintain load side voltage by injecting appropriate magnitude of voltage to the power line. This work presents simulation of single phase DVR using MATLAB/SIMULINK. In this model to generate pulses, Sinusoidal Pulse Width Modulation (SPWM) technique is implemented. This paper discusses the study of Proportional Integral (PI) controller and Fuzzy Logic (FL) controller. FL controller is able to give better performance than PI controller because when voltage sag occurs, FL controller gives robustness to system parameter variations and it has simplicity of execution.
Symmetrical and unsymmetrical voltage sags are a major cause of energy loss in induction motors a... more Symmetrical and unsymmetrical voltage sags are a major cause of energy loss in induction motors affecting the efficiency and longevity of the motor. A comprehensive and novel graphical method to determine energy loss during unsymmetrical sags is proposed. The energy is computed using torque–speed characteristics of the induction motor. Due to unbalance in the voltages during unsymmetrical sags, oscillations are observed in torque–speed characteristics. Throughout these oscillations, motor torque and speed attain extreme values. Area under the curve of torque and speed during oscillation is computed using MATLAB/Simulink simulation, which is a measure of the output power during unsymmetrical sags. The sag duration is measured to compute the energy loss. The analytical expression to assess output power of an induction motor during unsymmetrical sag is derived. The graphical results are validated using analytical calculations. Graphical representation is easy and faster to construct than analytical methods; in addition, the graphical method proposed makes it easier to assess the comparative magnitudes. Assessment of energy loss provides a useful tool for optimal injection of energy for sag mitigation techniques.
2018 International Conference on Smart Electric Drives and Power System (ICSEDPS), 2018
Power quality related issues are one of major concern in the present time. The most frequent powe... more Power quality related issues are one of major concern in the present time. The most frequent power quality related problems are voltage sag. To protect sensitive load from voltage sags in the network, a power electronic based device named Dynamic Voltage Restorer (DVR) is installed between the supply side and the sensitive load side. Its basic purpose is to maintain load side voltage by injecting appropriate magnitude of voltage to the power line. This work presents simulation of single phase DVR using MATLAB/SIMULINK. In this model to generate pulses, Sinusoidal Pulse Width Modulation (SPWM) technique is implemented. This paper discusses the study of Proportional Integral (PI) controller and Fuzzy Logic (FL) controller. FL controller is able to give better performance than PI controller because when voltage sag occurs, FL controller gives robustness to system parameter variations and it has simplicity of execution.
Symmetrical and unsymmetrical voltage sags are a major cause of energy loss in induction motors a... more Symmetrical and unsymmetrical voltage sags are a major cause of energy loss in induction motors affecting the efficiency and longevity of the motor. A comprehensive and novel graphical method to determine energy loss during unsymmetrical sags is proposed. The energy is computed using torque–speed characteristics of the induction motor. Due to unbalance in the voltages during unsymmetrical sags, oscillations are observed in torque–speed characteristics. Throughout these oscillations, motor torque and speed attain extreme values. Area under the curve of torque and speed during oscillation is computed using MATLAB/Simulink simulation, which is a measure of the output power during unsymmetrical sags. The sag duration is measured to compute the energy loss. The analytical expression to assess output power of an induction motor during unsymmetrical sag is derived. The graphical results are validated using analytical calculations. Graphical representation is easy and faster to construct than analytical methods; in addition, the graphical method proposed makes it easier to assess the comparative magnitudes. Assessment of energy loss provides a useful tool for optimal injection of energy for sag mitigation techniques.
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