Impact of static synchronous compensator on flux‐based synchronous generator loss of excitation protection

Abstract

In order to increase the power transfer and providing the optimum utilisation of the power system capability, application of flexible alternating current transmission system (FACTS) devices technology, such as static synchronous compensator (STATCOM), has been attracted, in recent years. However, the STATCOM changes the voltage and current of the power system that disturb the operation of the impedance-based synchronous generator loss of excitation (LOE) protection. Then, this study proposes a new flux-based LOE protection method, in the presence of STATCOM, that is based on the local variation of the flux linkage of the generator available at the location of relay. The mentioned relay is independent of other generator protection relays without any coordination. In order to show the satisfying operation of the proposed method, some simulations have been carried out in the Matlab/Simulink software. A single-machine infinite bus and a three-machine infinite bus systems have been used in simulations. The results show that the presence of STATCOM has no important effect on the performance of proposed relay opposite to a negative offset relay with two protective zones (the widely used impedance method) which is affected by STATCOM operation.

Investigation of a New Method for Synchronous Generator Loss of Excitation Protection

“…There are several techniques based on magnetic flux variation in the air gap that have been presented ( [9] and [10]) but those techniques have been criticized. This is because in order to measure the machine flux, search sensors coil should be utilized but there is a natural reluctance to install it because it may lead to machine damage [8].…”

Providing a new method for protecting the loss of excitation of generator in the presence of phase‐shifting transformer

“…In more recent studies, methods of improving the performance of relays in the presence of FACTS devices have been developed. The study conducted in Yaghobi is an attempt to present an LOE protection method based on flux in the presence of STATCOM. It is also shown in Ghorbani et al that by transmitting the voltage and current information of the two ends of the GIPFC line, the GIPFC effect can be reduced in LOE protection.…”

Nonlinear T-S fuzzy stabilizer design for power systems including random loads and static synchronous compensator

“…Static synchronous compensator (STATCOM) is one of the important members of FACTS family that is vastly applied on long transmission lines in modern power systems. It plays various roles in the operation and control of power systems, such as scheduling power flow, decreasing unsymmetrical components, reducing net loss, providing voltage support, limiting short‐circuit currents, mitigating subsynchronous resonance, damping the power oscillation, and enhancing the transient stability . A power network with a STATCOM is a complex system with so many issues to be addressed.…”