Method and system for optimizing successive load shedding shutdown rule of pumped storage unit

Abstract

The invention provides a method and system for optimizing a successive load shedding shutdown rule of a pumped storage unit, and belongs to the technical field of hydroelectric generation.The method includes: firstly establishing a successive load shedding transition process simulation model; secondly, performing transition process simulation under different successive load shedding interval timesand operating water heads by utilizing the model, and finding the most dangerous successive load shedding interval time and the most severe operating water head by taking the deviation degree of thewater hammer pressure extreme values of the volute and the draft tube relative to the initial value as an index; and then, setting the simulation model input as a two-stage guide vane closing rule tobe optimized, the most dangerous successive load shedding interval time and the most severe operation water head, and performing guide vane closing rule optimization by taking a double-objective optimization function as an objective under the constraint conditions of control parameters and the objective function to obtain an optimal guide vane closing rule. According to the method, the differencebetween the transition processes of the first-throwing unit and the second-throwing unit during successive load throwing of the units is considered, and multi-unit optimal control is achieved.

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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