Study and Simulation of Voltage Profile Recovery on a 200 km Transmission Line Using Shunt Static Var Compensator (SVC)

Abstract

This article aims to clarify how Flexible Alternating Current Transmission Systems (FACTS) technology, for static operating devices, conditioned on application to long-distance transmission lines can solve problems related to voltage drop on paths known as “weak zones” of the power transmission system. Some technical aspects of the construction of the SVC Static Reactive Compensator in conjunction with thyristor switching devices such as TCR and TSC are described. The proposed scenario is similar to the Brazilian interconnected system, where much of the generator park is hundreds of miles from the country's major consumer centers, leading to the structure of this system longer transmission lines and consequently greater losses in the transmission paths. For the proposed simulations the MATLAB Simulink ® environment was used considering different voltage unbalance operating ranges caused by three-phase faults in the transmission lines. The conclusions show that the distance from the lines to the load has a great influence on the oscillatory effects of voltage, and the fact that the “loading” transmission lines can compensate for much of the path by generating wars through the circuit's natural capacitance. The allocation of capacitor and shunt reactor banks is a reliable option for the transmission system and can act as a support mechanism for voltage control maneuvers to circumvent abrupt changes in reactive demand. From the simulations output comparison, the transient effects showed greater stability in the voltage signal recovery in the stretches where the compensation blocks were located near the lowering substation bus, thus demonstrating the capacity of the applied technology.