A field programmable gate array-based location factor to improve the under-frequency load shedding

摘要

Automatic load shedding schemes can increase system reliability by preventing total system collapse during emergency operating situations when load exceeds generation. Large decreases in frequency can only occur when an area is separated from the interconnected system and is left with a generation-load imbalance. This may result from a major system disturbance that creates large power swings, causing protective equipment operation and system islanding. If the generation does not match the load in the isolated area, an automatic load shedding scheme based on system frequency can be used to maintain system stability and provide additional protection for remaining loads and other equipment. Underfrequency load shedding (UFLS) tripping frequency settings are selected for some specific emergency situation, which are considered more probable for a specific power system. It is not possible to predict all situations that can happen in the power system. The amount of the load value to be shed is the main issue. Redundant tripped load can create an over frequency situation, which is more dangerous than underfrequency problem. Therefore, a field programmable gate array-based location factor is proposed to determine where and how much load should be shed.