Series Compensation Technique for the Synchronization of Grid Voltage with DG System under Fault Condition

Abstract

The use of series capacitors is to reduce the voltage drop in the lines with low power factor and improve the voltage at the receiving end particularly with low power factor loads. For variable load conditions, the voltage can be controlled by switching in suitable series capacitors in the line. Series compensation is defined as insertion of reactive power elements into transmission lines and provides the following benefits are reduce the voltage drops, increases the system response, stability and efficiency also increases the transfer capabilities.In order to achieve satisfactory results with such systems, it is necessary to count on accurate and fast grid voltage synchronization algorithms, which are able to work under unbalanced and distorted conditions. This project analyzes the synchronization capability of three advanced synchronization systems: the decoupled double synchronous reference frame phase-locked loop (PLL), the dual second order generalized integrator PLL, and the three-phase enhanced PLL, designed to work under such conditions. Although other systems based on frequency-locked loops have also been developed, PLLs have been chosen due to their link with dq0 controllers. The simulation results are presented by using Mat lab/Simulink software.