Security constraint economic dispatch method based on security domains

Abstract

The invention relates to an electrical power system and provides a network security constraint of a processing system in a traditional optimized operation problem of electrical power system economic dispatch. The network security constraint comprises a branch power flow constraint, a static voltage stability constraint and a transient stability constraint, and provides an effective way for coordinating contradiction between economy and security. A security constraint economic dispatch method based on the security domains comprises a first step of respectively calculating an active static security domain boundary coefficient, a cut-set voltage stability domain boundary coefficient and a movable security domain boundary coefficient, a second step of building a security constraint economic dispatch model based on the security domains, a third step of utilizing social evolutionary programming based on cognition to work out the unit start-stop state optimization sub-problem, a fourth step of calculating out power generation cost, static voltage stability margin and transient stability margin of each unit in dispatching cycle, and a fifth step of obtaining a feasible economic dispatch scheme, or returning to the third step. The security constraint economic dispatch method is mainly applied to electrical power load dispatch optimization.

Description

technical field [0001] The invention relates to an electric power system, in particular, to a safety-constrained economic scheduling method based on a safety domain. Background technique [0002] Power system economic dispatch is an effective tool to ensure reliable power supply of loads and improve system operation economy, and plays an important role in safe, reliable and economical operation of power system [1] . Power system economic dispatch can be divided into static economic dispatch and dynamic economic dispatch [2] , the static economic dispatch is for a specific time section, by adjusting the active and reactive power output of the unit, the tap of the transformer, etc., to achieve the optimization goals such as the minimum cost or the best power quality, such as the optimal power flow problem [3] (OptimalPowerFlow, OPF); dynamic economic dispatch is aimed at a certain dispatch period, which can be divided into multiple static time sections, and each time section...

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Problems solved by technology

[0004] At present, many literatures have considered constraints such as transient stability in OPF [5-8] , the methods for dealing with transient stability constraints are generally methods based on time domain simulation and methods based on energy functions [5] , these two methods have problems such as large amount of calculation, complex model and inconvenient solution. On the one hand, the root cause lies in the complexity of the power transient stability problem itself; "point method" (that is, aiming at the predetermined pre-accident system operation state, such as the point where the node is injected into the power space, through time-domain simulation or direct method to determine whether the system can recover to a stable state after the predetermined accident occurs), this analysis and The operating status of the system is strictly related. When the operating status changes, it needs to be re-analyzed

In the dynamic economic dispatch of the power system, the relevant literature has considered constraints such as branch power flows and node voltages [9] For example, literature [10] embeds OPF into the UC problem, considering branch power flow constraints and node voltage constraints; literature [11] introduces system dynamic stability constraints in the UC problem of multi-area interconnection systems; Static voltage stability constraints and transient stability constraints are not introduced in the UC problem

To sum up, in the current power economic dispatch, there are problems such as it is difficult to consider the static voltage stability constraints and transient stability constraints, and it is impossible to effectively evaluate the safety margin of the economic dispatch scheme.

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