LIMITED CAPACITY DYNAMIC VOLTAGE RESTORER FOR VOLTAGE REGULATION IN RADIAL DISTRIBUTION FEEDER

Abstract

The distribution system is one of most important and critical part of power system. The variation in the voltage at load end is of great concern in the distribution system. The voltage is required to be kept regulated within a specified range in the distribution system. Series compensation is technically more suitable solution for regulating the voltage in the radial distribution feeder when compared with shunt compensators. Two vital factors which decide the quality of compensation are the location of series compensation device and the rating of the device. The optimum location of device can be found, using various algorithms optimization technique with multiple restrain. But its optimum location changes every time a fault or large transients occur on the feeder. The rating of device increases with the amount of compensation required to achieve requisite regulation. This thesis presents an alternative for the conventional lumped series compensation devices prevalent in distribution power systems. The two measures presented in the thesis are curative measures and remedial measures. Curative measure is implemented with the distributed capacity limited DVR as a future course of action to enable efficient and cost-effective voltage regulation on radial feeder. Number of capacity limited DVR are incorporated into the feeder without affecting its power flow. An autonomous control for controlling the D-DVR is investigated to efficiently regulate the voltage on radial feeder in a cost-effective manner. The performance of the D-DVR is evaluated using MATLAB simulation environment to validate the concept of D-DVR and its autonomous control through simulated results under perturbing load and source conditions. Remedial measure is also been studied to improve the response of OLTC transformer installed on the feeder by operating it in conjunction with the capacity limited DVR for step-less operation. Control algorithm for the same is developed. The performance of duo has been investigated and validated using MATLAB/SIMULINK environment under load and source dynamics.