All kinds of equipment in the power system may have different types of failures in operation, which affect the normal operation of the power system and the normal supply of electricity to the customers. Power system reliability is the measure of the ability of the power system to supply power and electrical energy to customers uninterruptedly according to acceptable quality standards and the required quantity.
The interruption of power supply to customers due to power shortage or accidents in the power system will cause different degrees of losses to industrial and agricultural production and people’s life. Therefore, power supply enterprises have been taking various technical and management measures to improve the reliability of power supply in the planning, design and operation stages of the power system for a long time.