A 10 kVA dynamic voltage restorer real time implementation in textile industry to address the power quality issues

Abstract Power Quality issues are the major concern for the most of the industry and home appliances. The power quality (PQ) issues such as fast variation in voltages, under voltage, over voltage, harmonics, unbalance and flickering causes huge financial loss to the industries. Dynamic Voltage Restorer (DVR) is one of the solutions to maintain voltage quality on the point of connection of the load. A 10 kVA Dynamic Voltage Restorer (DVR) using Modified Synchronous Reference Frame-Phase Locked Loop (SRF-PLL) and Proportional Resonant (PR) controller were developed. The developed DVR employs three single-phase series voltage controllers to compensate for voltage sags in each individual phase and a three-phase shunt controller to maintain the DC bus voltage. The modified SRF-PLL has been used to extract the load references which are in phase with the positive sequence of the grid voltage. The drawbacks of the conventional Proportional Integral (PI) controller such as yielding steady state error has been addressed by the PR controller which can effectively track varying references by the virtue of high gain at the operating point. The performance of the developed DVR has been tested using MATLAB simulations and also validated with the experiments on hardware prototype with the programmable load to create the dynamics such as under voltage, over voltage, and unbalance in the load. Further, on field trials and performance evaluation of the developed DVR proto unit is carried out in a spinning mill unit of a textile industry in South India. This exercise was carried out to propose a solution to the degraded performance of 10 kW active front end rectifier of the motor drive in the spinning mill, due to poor power quality. The developed DVR proto-unit could maintain regulated AC voltage with good waveform quality during different grid side disturbances. The performance of proposed DVR shows that it’s implementation can address multiple PQ issues in industries.