Precautions taken against short-term voltage drops in medium voltage networks

Using precision loads has increased in design of the industrial systems with increasing technology expectations. Power quality and productivity of energy have become problems of distribution lines. Number of consumers increase day by day. While avaliable lines are used by users that have different sensivities, on the other part, distributed renewable energy generation systems becomes widespread. Short circuit failures in distribution lines, large-scale loads which cut-in and out and reactive power flows cause short-term voltage drop. When the voltage drop stay out of steady state working limits of controllers, it causes great economic losses for industrial consumers and causes uncomfortable consumption for consumers with low power rating. In order to solve these problems, flexible Alternating Current Systems (FACTS) devices which respond to changes in system dynamics quickly are widely used. Distribution System Static Synchronous Compensator (D-STATCOM) is one of FACTS devices that are used in distribution systems. In this study, D-STATCOM which is one of the flexible alternative devices has been used as a precaution against short-term voltage drops that may occur in different scenarios in a radial medium voltage network. When D-STATCOM has been activated or not, it has been simulated for some cases such as short-circuit, sudden load increase or voltage rise current which is generated in a radial network that was modelled in matlab/simulink program. Simulation results has been presented oscillographically and evaluated system behaviors. Simulation results that obtained at determined points in radial network demonstrate d-statcom device achieves to keep bus voltages in nominal range.