Frequency control method and system for interconnected power system containing energy storage resources

Abstract

The invention discloses a frequency control method and system for an interconnected power system containing energy storage resources. The control method comprises the following steps: establishing a frequency response model of a regional interconnected power system containing energy storage frequency modulation resources; performing frequency division processing on the ACE signal to obtain a powerreference value borne by a traditional unit and an energy storage resource; establishing a space state model and discretizing the space state model; designing a distributed model prediction controller, and establishing an optimization objective function and constraint conditions; and solving a quadratic programming problem formed by the optimal objective function and the constraint condition to determine an optimal control sequence, and enabling a first control variable in the control sequence to act on a traditional unit and energy storage resources to realize optimal control. The control strategy provided by the invention can reasonably allocate the frequency modulation responsibilities of a traditional unit and the energy storage resources, gives play to the advantages of quick outputof energy storage and large frequency modulation capacity of the unit, and can quickly stabilize the frequency fluctuation caused by load and new energy injection in a power system.

Description

technical field [0001] The invention belongs to the technical field of electric power system automatic control, and in particular relates to a frequency control method of an interconnected electric power system including energy storage resources. Background technique [0002] In order to ensure the reliable and safe operation of the power system network, the transmission power of the tie line and the system frequency must be kept within the specified range. In the interconnected power system, when the load changes are uncertain, the frequency and the transmission power of the tie line will deviate from their predetermined values, which will lead to abnormal operation of the entire power system network when it is serious. Nowadays, renewable energy sources such as wind power and photovoltaics are connected to the grid on a large scale, and their uncertain output characteristics have increased the frequency regulation pressure of the power grid. In order to ensure the reliable...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the above-mentioned existing technical deficiencies, the present invention provides a frequency control method for an interconnected power system including energy storage resources. The power demand is divided into high-frequency power demand and low-frequency power demand through a filter, and then the energy storage Resources and traditional thermal power units are responsible for solving the problem that energy storage frequency modulation resources are treated as the same as traditional thermal power unit frequency modulation resources, so that the frequency modulation advantages of energy storage resources cannot be fully utilized

In addition, the distributed model predictive control solves the problem that the conventional proportional-integral controller (hereinafter referred to as PI controller) is not ideal in dealing with power systems with a large number of nonlinearities and constraints. According to the system frequency deviation, tie-line power deviation, and the power output reference trajectory of the upper power allocation layer to realize dynamic control of frequency modulation resources

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