Optimization control method based on self-adaptive virtual inertia parameters

Abstract

The invention discloses an optimization control method based on self-adaptive virtual inertia parameters. The method comprises the following steps of: 1, acquiring a frequency change rate and a frequency offset of a grid-connected point of a system, and obtaining a virtual inertia coefficient by combining values of an anti-misoperation coefficient and a symbol item according to a corresponding criterion; 2, superposing an additional active instruction with a real-time power instruction issued by a fan master controller to obtain a total active instruction; 3, inputting the deviation value of the total active instruction and the fan active detection value into a PI regulator to obtain active and reactive current instructions; and 4, comparing the active and reactive current instructions with the actual active and reactive current, and respectively inputting the obtained current deviations into the PI regulator to obtain active and reactive voltage instructions, so that modulation is carried out by an SVPWM link, and a machine-side converter switching tube control signal is generated. According to the invention, the virtual inertia coefficient of the system can be smoothly adjusted according to the frequency fluctuation of the grid-connected point, thereby reducing the overshoot and adjustment time of the frequency response, and optimizing the inertia support capability of the system.

Description

technical field [0001] The invention relates to the field of wind power generation, in particular to a control method for enhancing and optimizing the inertia support capability of wind power grid-connected units. Background technique [0002] Wind energy, as one of the non-polluting and widely distributed new energy sources, has attracted more and more attention and has been widely used. In recent years, my country's wind power industry has developed rapidly, and the installed capacity of wind power has leapt to the first place in the world. The large-scale wind power connected to the power grid has brought new challenges to the frequency stability of the power grid: under the traditional power grid, the generator set is directly connected to the power grid through a step-up transformer. With a large moment of inertia, when the frequency of the grid fluctuates for a short time, the unit can spontaneously absorb or release part of the active power to support the grid frequenc...

AI Technical Summary

Problems solved by technology

There are various forms of virtual inertia coefficients, and the existing ones have constant forms, namely K v = K d ; Bang-Bang control form, namely K v Switch between two limited values ​​according to system frequency fluctuations; in these two schemes, the working state of the system is not flexible enough, and in the system using the Bang-Bang control form, the control fluctuation caused by the virtual inertia coefficient switching is in the It is unavoidable that when the system frequency fluctuates, it is generally difficult to meet the requirements of fast and stable frequency response; it is imperative to optimize the frequency response performance of wind turbines

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