A frequency control method for wind diesel storage microgrid

Abstract

The invention discloses a method for controlling the frequency of a wind fuel storage micro-grid. Firstly, the power prediction is performed to obtain the predicted load value and the predicted value of wind power generation power per second in the prediction period, and the power distribution of the wind power generator and the diesel generator is carried out according to the predicted value. The set power value is obtained, the difference between the set power value and the real-time output power value is input, and the power adjustment is output, and the power adjustment is obtained by using the fuzzy control strategy; and the active disturbance rejection controller is used to compare the real-time frequency The offset value of the rated frequency Δfref=0 is the set value. The extended state observer is used to observe the influence of the disturbance on the frequency fluctuation, and it is compensated in real time, so that the frequency of the wind diesel storage microgrid is stable near the rated frequency value. The invention utilizes the prediction information to arrange the power generation plan of the fan and the diesel engine in advance, and uses the active disturbance rejection controller to control the real-time frequency of the energy storage battery, thereby improving the anti-interference ability and robustness of the system frequency.

Description

technical field [0001] The invention belongs to the technical field of wind fuel storage micro-grid control, and more specifically relates to a frequency control method for wind fuel storage micro-grid. Background technique [0002] Since the construction of conventional centralized power grids in remote areas is too expensive to rely on large power grids for power supply, other methods of power supply are required. Initially, the power supply system in remote areas was mainly powered by diesel generators, but the cost was high and it would cause serious pollution to the environment. In recent years, from the perspective of economy and environmental protection, renewable energy such as wind energy has been introduced to generate electricity. However, wind energy has the characteristics of randomness and intermittentness. In order to compensate the fluctuation of wind power output power, energy storage batteries are introduced into the wind-fired diesel system to improve the...

AI Technical Summary

Problems solved by technology

On the one hand, due to the unpredictability of the load and the volatility and intermittency of renewable energy such as wind power generation, it is easy to have an imbalance between the supply and demand of active power during the operation of the microgrid island, resulting in fluctuations in the frequency of the microgrid, making the microgrid island Frequency control during operation is more difficult; on the other hand, due to the introduction of a large number of power electronic interfaces, the inertia of the microgrid system is very weak, which makes the system frequency change rapidly and frequently after the disturbance occurs, and in severe cases, it may even cause the system to be disconnected.

[0004] Considering the fast response speed of energy storage batteries, the slow response speed of diesel generators, and the fact that wind energy fluctuations and intermittency are difficult to control. At present, most of the microgrid frequency control methods mainly rely on energy storage batteries to control. , the requirements for energy storage batteries will be relatively high, and the corresponding cost will also increase

At the same time, in the traditional droop control strategy, it is difficult to set the droop control coefficient, and there are problems of poor anti-interference ability, static error, and conflict between response speed and overshoot

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