Method for calculating chain fault probability of parallel power supply system

Abstract

The invention relates to a method for calculating the chain fault probability of a parallel power supply system, which comprises the steps of S1, acquiring line operation data from a power grid energy management system (EMS), wherein the line operation data comprises the number of line overload times, the time and occurrence conditions, determining a Poisson distribution function of the overload probability of an ith line by adopting a Monte-Carlo simulation method, and determining a parameter Lambda; S2, acquiring transformer operation data from the power grid EMS, wherein the transformer operation data comprises the number of transformer overload times, the time and occurrence conditions, determining a Poisson distribution function of the overload probability of an ith transformer by adopting the Monte-Carlo simulation method, and determining a parameter Lambda<Ti>; S3, calculating the n times of line chain fault probability of the parallel power supply system with the calculation formula being defined in the description, wherein the n is greater than or equal to 1 and less than or equal to NL; S4, calculating the n times of transformer chain fault probability of the parallel power supply system with the calculation formula being defined in the description, wherein the n is greater than or equal to 1 and less than or equal to NT; and S5, calculating the chain fault probability of the parallel power supply system with the calculation formula being defined in the description. The method provided by the invention can provide necessary technical support for power grid dispatching operations.

Description

technical field [0001] The invention relates to a method for calculating the probability of serial faults in a parallel power supply system. Background technique [0002] figure 1 in, by N L lines parallel operation and N T transformer Parallel operation constitutes a power supply system, assuming that the load power is S D (S D =P D +jQ D ). This is a common grid structure in transmission and distribution networks. [0003] The line is connected to the same or multiple power sources, and its load rate shows different levels under different power generation power. Once the line connected to a certain power supply is overloaded and out of operation, the power stopped due to overload will be transferred to other lines. If the stop power is large, the transfer power will also be large, which will often cause serial overloads on other lines, leading to further serial failure accidents. The high-voltage side of parallel transformers is connected to the line, and t...

AI Technical Summary

Problems solved by technology

[0004] If multiple lines running in parallel or multiple transformers are out of operation due to ground fault or short circuit fault, it will also cause the transmission power to be transferred to other lines or transformers

Once the transfer power is too large, a series of overload accidents will also occur, which will lead to the expansion of the grid accident and cause greater impact and loss

The chain overload caused by faults is caused by the uncertainty and randomness of the line and transformer health status and load power.

[0005] Aiming at the chain overload and chain fault of the power system, the power flow calculation method is usually used to judge and confirm in the past, but this calculation method cannot determine the probability of chain overload or chain fault in the power grid, let alone determine the occurrence of chain overload or chain fault. Number of breakdowns and losses

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