Open AccessImpact of Fixed Series Capacitors and SSSC on the LOE Protection of Synchronous Generator
Author(s) -
Amir Ghorbani,
Hossein Mehryari Lima,
Allahverdi Azadru,
Babak Mozafari
Publication year - 2015
Publication title -
journal of electrical engineering and technology/journal of electrical engineering and technology
Language(s) - English
Resource type - Journals
eISSN - 2093-7423
pISSN - 1975-0102
DOI - 10.5370/jeet.2015.10.4.1453
Subject(s) - relay , control theory (sociology) , capacitor , generator (circuit theory) , protective relay , permanent magnet synchronous generator , electrical impedance , voltage , matlab , series (stratigraphy) , electric power system , ac power , computer science , engineering , power (physics) , electrical engineering , physics , paleontology , control (management) , quantum mechanics , artificial intelligence , biology , operating system
Loss of excitation (LOE) relay is prevalently used to protect synchronous generator. The widely used method for synchronous generator LOE protection is a negative offset mho relay with two zones. The basis of this relay is identical to mho impedance relay. In other words, this relay calculates impedance by measuring voltage and current at the generator terminal. On the other hand, the presence of series compensation, changes measured voltage and current signals during loss of excitation. This paper reveals that the presence of series compensators such as fixed series capacitors (FSCs) and static synchronous series compensator (SSSC) causes a significant delay on the performance of generator LOE relay. It is also shown that the presence of SSSC causes the LOE relay to be under-reached. Different operating modes of the power system, the SSSC and also different percentages of series capacitive compensations have been considered in the modeling. All the detailed simulations are carried out in the MATLAB/Simulink environment using the SimPowerSystems toolbox.