Enhancement of Critical Clearing Time to test system IEEE-9 by using combination or distribution Static Synchronous Compensators (STATCOMs)

This paper aims to use Static Synchronous Compensators (STATCOMs) in two cases combined or distributed, where it act in the first case as one compensator at one placement of electrical network, for the same required power of studied network, and distributed compensators as multi-STACOM with suitable powers in the second case where they are connected at the best placements of studied network, for improving critical clearing time of IEEE-9 nodes test system and its transient stability.

Enhancement of voltage Stability in power transmission networks using Static Compensator (STATCOM( based on Fuzzy logic

The fluctuation of voltage cannot be tolerant for equipment in modern industrial plants such as lighting loads, PLC, robots, and another equipment, which exist in transmission and distribution systems, so we should use proper aids to regulate voltage and control it. In this study a (± 25Mvar) Static Synchronous Compensator (STATCOM) is used to enhance voltage stability in a (66 kv, 1500MV.A) power transmission network. The STATCOM in this study regulates the voltage of the transmission network for changing in voltage (± 7%) from the nominal value. A model of the power transmission system and another model of the STATCOM device, which will enhance the stability of voltage are designed in MATLAB/Simulink. And the control of (STATCOM) is achieved by using a Proportional Integrative (PI) controller with Fuzzy Logic Supervisor to adjust the parameters in PI controller in DC voltage regulator during transient states of load changing which gives more stability in DC voltage. The results of the simulation are shown. This study demonstrates the ability of STATCOM for regulating the voltage of the transmission system by injecting and absorbing reactive power from the power system, and the DC voltage be more stability by using Fuzzy Logic supervisor.

Impact of Reactive Compensators on Performance of Distance Protective Relays

This paper tries to clarify the impact of parallel and serial compensation of power transmission lines on the performance of distance relays which protect these lines. To this end, power system analysis software (NEPLAN) will be used for explaining distance relay behavior in the presence of different parallel or serial reactive power compensators, with main types of faults that may occur in different locations on the protected line. In this paper, Syrian power transmission network is simulated using (NEPLAN) software, and three reactive power compensators: parallel (STATCOM), serial (TCSC), and unified (UPFC), are used to compensate reactive power on transmission line. Several simulations, in many cases are carried out to illustrate the impact of fault type and location on the measured impedance seen by the distance relay. The objective of identifying the impact of reactive compensators on fault impedance seen by distance relay (i.e. fault location), is to determine the possible ways to resolve the problem and improve the performance of transmission line protection.