Probability assessing method for stage type protection operational risk of electric power system

Abstract

The invention discloses a probability assessing method for a stage type protection operational risk of an electric power system, and the probability assessing method belongs to the field of the relay protection of the electric power system and the reliability of the electric power system. The probability assessing method comprises the following steps: determining a protection system to be assessed and a false action source set; carrying out invalidation classification analysis on the protection system to be assessed; calculating the instantaneous false action probability of a protection element in the false action source set in a new electric network structure and in a power flow state; if the false action of the protection system in the false action source set also cuts off a line where the false action is positioned, carrying out N-2 power flow calculation to obtain load loss corresponding to a current faulty line; calculating the instantaneous non-startup probability of the protection element in the false action source set and the load loss caused by a remote backup action; calculating the risk indicator, the total instantaneous false action probability and the total instantaneous non-startup probability of the protection system to be assessed; and judging a weakest protection link in the electric network. The probability assessing method has the beneficial effects that the principle characteristic of protection is reflected, and the action rejection probability, the false action probability and the corresponding operational risk of the protection can be quantitatively calculated.

Description

technical field [0001] The invention belongs to the fields of power system relay protection and power system reliability, and in particular relates to a probability assessment method for the operation risk of staged protection of the power system. Background technique [0002] At present, the power systems of various countries in the world are large in scale and complex in structure. The huge power demand and asset economic operation have made the stability margin of the power grid smaller and smaller. As the first line of defense to ensure the safety of the power grid, the refusal and malfunction of the relay protection system Disturbance has become one of the factors that trigger or accelerate system disturbance, and the reliability and failure risk of relay protection are not optimistic. [0003] Up to now, in the risk assessment of power system operation, the consideration of the reliability model of the protection system is still relatively rough. In order to improve t...

AI Technical Summary

Problems solved by technology

However, the short-term dynamic reliability and risk of the relay protection system, that is, the "safety degree", is not considered enough. The evaluation process is difficult to effectively reflect the actual risks faced by the power grid due to the reliability changes in the relay protection operation, or because the relay protection system is not considered. The impact of the actual operating environment on it is difficult to effectively reflect the actual operating risk of relay protection when the system mode changes

There are literatures describing the risk calculation methods of distance protection and Special Protection System (SPS), but they pay more attention to the calculation of protection failure probability, and the risk assessment process needs to be improved

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