SOLUTION FOR STABILIZING VOLTAGE BY SERIES COMPENSATOR ENSURE THE OPERATION OF MEDICAL EQUIPMENT AGAINST THE INCREASE / DECREASE OF VOLTAGE

116 views

Abstract

A series compensator is an electrical device used in a distribution system in order to improve the power quality. Its main function is to mitigate the increase/decrease of grid voltage that can affect sensitive loads. Medical equipment is one of the loads requires the high voltage quality. Although its own voltage stabilization system inside, however, in case of a short-circuit happen on the grid nearly the load, it leads to a rapid increase/decrease in voltage, which exceed the limits of the device. Especially in the case of rapid increase / decrease of voltage with phase angle jump and occur in a long time, it can affect the operation of equipment (inaccuracy of control devices, stalling of loads). In this paper, we propose a solution that uses a structure of an AC-DC converter to provide power in long-term voltage drop mode and a DC-AC converter to generate a compensation voltage for the device. An algorithm and control structure are also proposed to ensure the quick and accurate compensation function of the serial compensator. The effectiveness of method is demonstrated by simulation results in MATLAB/Simulink.