A method and system for optimizing the shutdown law of sequential load shedding of pumped storage units

Abstract

The invention proposes a method and a system for optimizing the shutdown law of successive load shedding of pumped storage units, belonging to the technical field of hydroelectric power generation. Firstly, a simulation model for the transition process of successive load shedding is established; secondly, the model is used to simulate the transition process under different successive load shedding intervals and operating heads, and the degree of deviation of the extreme value of the water hammer pressure of the volute and draft tube from the initial value is given by Index, find the most dangerous successive load shedding interval time and the worst operating head; then, set the simulation model input as the two-stage guide vane closing law to be optimized, the most dangerous successive load shedding interval time and the worst operating head, in Under the constraints of control parameters and objective function, the optimal guide vane closing law is obtained by taking the dual-objective optimization function as the objective to optimize the guide vane closing law. The invention considers the difference between the transition process of the unit shedding first and the unit shedding later when the load shedding of multiple units is successively carried out, and realizes the optimal control of the multi-units.

Description

technical field [0001] The invention belongs to the technical field of hydroelectric power generation and relates to the technical field of control of pumped storage units, in particular to a method and system for optimizing the closing law of guide vanes of sequential load shedding of pumped storage units. Background technique [0002] Pumped storage is the main form of dynamic storage of electric energy in the power system. It undertakes heavy tasks such as peak regulation, frequency regulation, and emergency backup. It is the key to maintaining the safe and stable operation of the power system. When the power grid or the unit fails and the pumped storage units shed load one after another, the governor controls the guide vane to close according to the established law. In this process, the two core indicators are: the maximum speed index of the unit (speed index) and the comprehensive pressure index of the water system (comprehensive pressure index), the smaller the better....

AI Technical Summary

Problems solved by technology

[0004] However, the prior art represented by patent 2017114304665 optimizes the closing law of the load shedding guide vane only for a certain working condition.

Moreover, the existing optimization method is single-unit optimization, and the optimized guide vane closing law is applied to all units, ignoring the difference between the transition process of the first unit and the second unit during successive load shedding, and the optimal control cannot be achieved Effect

In addition, in order to balance the speed index and the comprehensive pressure index in the successive load shedding transition process, the current optimization methods usually add weighted sums and convert them into a single objective. Not only the weight coefficient depends on empirical determination, but also the optimization efficiency is low

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