A Static Risk Assessment Method for Power System Based on Mixed Power Flow

Abstract

The invention discloses a method for evaluating the power system static risk based on hybrid power flow. The method comprises the steps that (1) according to the current structure of a power system and a planning scheme, a corresponding planning scheme model is established; (2) according to equipment data and the structure of a power grid, predicated faults of the power grid and the possibility of the predicated faults are analyzed, and then a predicated fault set is established; (3) the power flow corresponding to all the faults in the predicated fault set is worked out through the risk state based on the hybrid power flow, and for the fault with power flow out of range, load loss is used as a fault consequence; (4) according to the load loss of the fault states and the possibility of the fault, the system risk indicator is worked out; (5) according to the system risk indicator, the weak link of the system is found. According to the method for evaluating the power system static risk based on the hybrid power flow, the problem that when high-order fault occurs in a large complicated power grid, misconvergence of power flow is caused due to the fact that only alternating-current power flow is applied during risk evaluation is solved through the hybrid power flow.

Description

technical field [0001] The invention belongs to the field of grid planning and relates to the field of power system risk assessment Background technique [0002] Most of the traditional power grid planning and design studies focus on the problem of determining the number and location of the transmission lines to be built to minimize the total investment cost on the basis of meeting the future load demand. Among them, when comparing planning schemes and checking safety and stability, deterministic methods are generally used to evaluate the reliability of planning schemes. A deterministic approach is to study the reliability level of the grid in the event of expected failures. The most commonly used deterministic method is the system N-1 or N-K method, that is, when any one or K components (such as generators, lines, transformers, etc.) fail to stop running, calculate the power flow and node voltage of the line in the system, and verify Whether it is overloaded or the voltag...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the deficiencies of the traditional power grid planning evaluation method, the present invention provides a static risk evaluation method of the power system based on mixed power flow, which comprehensively evaluates the safety level of the power system by using the risk evaluation technology and combining the probability of failure and the severity of its consequences. In the process of power flow calculation, combining the advantages of AC power flow method and DC power flow method, using mixed power flow to overcome the problem of non-convergence of power flow encountered in complex large power grids and high-order faults when using AC power flow method alone

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