An Optimal Control Method Based on Adaptive Virtual Inertial Parameters

Abstract

The invention discloses an optimization control method based on self-adaptive virtual inertia parameters. The steps include: 1. Collect the frequency change rate and frequency offset of the grid-connected point of the system, and combine the corresponding criteria to select the anti-misoperation coefficient and symbol item value to obtain the virtual inertia coefficient; 2. Superimpose the additional active power command and the real-time power command issued by the fan master control to obtain the total active power command; 3. Input the deviation between the total active power command and the fan active power detection value into the PI regulator to obtain the active power , Reactive current command; 4. Compare the active and reactive current commands with the actual active and reactive currents, and input the obtained current deviations into the PI regulator to obtain active and reactive voltage commands, which are modulated by the SVPWM link to generate The control signal of the switching tube of the machine-side converter. The invention can smoothly adjust the virtual inertia coefficient of the system according to the frequency fluctuation of the grid connection point, thereby reducing the frequency response overshoot and adjustment time, and optimizing the inertia support capacity 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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