Optimal reclosure moment fast algorithm based on dynamic safety margins

Abstract

The invention discloses an optimal reclosure moment fast algorithm based on dynamic safety margins. The optimal reclosure moment fast algorithm includes the following steps that 1, a proper angle limit value delta <lim> and a proper initial search step size T are selected according to a basic operating point Y<0> of a system, and the search direction of a critical point is determined through a least-square fitting method; 2, the dynamic safety margins at different reclosure moments, boundaries and stability margin vectors eta under given node power increase vectors D are calculated, and the reclosure moment t<m> corresponding to the eta maximum value point is found; 3, the search step size is reduced to t, the step 2 is repeated within a left neighborhood (t<m>-t,t) and a right neighborhood (t, t+t<m>) of t<m>, and an optimal reclosure moment t<orc> and an optimal coincidence window are determined; 4, a power transfer limit P of a path at the optical reclosure moment is calculated. Calculation errors of the dynamic safety margins (DSR) can be effectively reduced, and a precise hyperplane coefficient is provided for calculation of the optimal reclosure moment; the practicality of an optimal reclosure moment setting method based on the dynamic safety margins is promoted.

Description

technical field [0001] The invention belongs to the field of electrical equipment and electrical engineering, and more specifically relates to a fast algorithm for optimal reclosing time based on a dynamic security domain. Background technique [0002] Current operating experience shows that most of the faults in the power system are overhead transmission line faults, and transient faults account for 80% to 90% of overhead transmission line faults. Therefore, automatic reclosing devices are widely used in the system to improve the continuity of power supply and the stability of the power system. [0003] However, at the current technical level, it is still difficult to realize reliable adaptive reclosing. The general practice is to close the circuit breaker again after a preset fixed delay after the relay protection trips to remove the fault. If it is a transient fault, the reclosing can be successful, and the system will enter a new normal operating state; if it is a perm...

AI Technical Summary

Problems solved by technology

[0006] 1. The search for the critical point adopts the quasi-orthogonal point selection method, which requires a lot of calculation time

[0007] 2. When the DSR boundary moves in parallel with the reclosing time, the dynamic safety measure and instability can well reflect the influence of the reclosing time on the system stability; and when the DSR boundaries corresponding to different reclosing times are not When parallelism is satisfied, using these two indicators to evaluate the stability of the system will inevitably lead to errors

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