A system integrity protection scheme for transient instability using synchronized measurement

This paper introduces a new system integrity protection scheme (SIPS) incorporated synchronous measurement and control actions of thyristor controlled series compensation (TCSC). To achieve optimal control strategy without compromising response time, a security guideline is developed during offline conditions. E-SIME is utilized to calculate the OMIB equivalent model and stability margin for multiple fault scenarios. The corresponding control actions are obtained by offline simulations. The fault conditions and the control actions required are taken as a learning set and sent to an automatic learning (AL) approach. The output of the AL approach is a security guideline. During online monitoring and control, the OMIB equivalent system and stability margin will be calculated every sampling period using synchronized measurement information. Once a fault condition is detected, the security guideline will directly provide optimal solution to deal with the extreme conditions. The TCSC is modeled as a variable capacitor, which can be switched in instantaneously and the compensation level can be flexibly adjusted. The close loop control, providing continuous and accurate control, is adopted in this SIPS This method was tested in two-area system, showing promising results.