Micro-grid frequency control method based on optimization of electric vehicle

Abstract

The invention relates to a micro-grid frequency control method based on optimization of an electric vehicle, the micro-grid frequency control method is applied to a micro-grid, the micro-grid comprises a thermal power generator, a wind driven generator and an electric vehicle, and the method comprises the following steps: designing an electric vehicle model composed of a hybrid energy storage system; according to different operation states of the hybrid energy storage system, the electric vehicle is controlled to carry out cooperative frequency control on the micro-grid; and adding a super-spiral second-order sliding mode controller to control the frequency of the micro-grid. The hybrid energy storage system composed of the energy storage battery and the super capacitor and the super-spiral second-order sliding mode controller are added, the control precision of a traditional thermal power generating unit can be improved, and the robustness and operation stability of the micro-grid are improved.

Description

technical field [0001] The invention belongs to the technical field of micro-grid frequency control, in particular to a micro-grid frequency control method based on optimized electric vehicles. Background technique [0002] Microgrid is a new type of power grid structure, which can independently complete the processes of distributed power generation, load power consumption, and energy storage. It has the characteristics of on-site mining, on-site consumption, and no need for long-distance transmission. One of the main modes of application, the development of microgrid makes its frequency control more and more important, PID algorithm is widely used in frequency control design because of its simple structure, but the accuracy of PID control frequency is not high enough to be very well meet the frequency requirements of the microgrid. [0003] Due to the increasingly serious environmental pollution, low-carbon life has become a trend, such as integrating new energy into the g...

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Problems solved by technology

[0002] Microgrid is a new type of power grid structure, which can independently complete the processes of distributed power generation, load power consumption, and energy storage. It has the characteristics of on-site mining, on-site consumption, and no need for long-distance transmission. One of the main modes of application, the development of micro-grid makes its frequency control more and more important, PID algorithm is widely used in frequency control design because of its simple structure, but the accuracy of PID control frequency is not high enough to be very Well-suited to microgrid frequency requirements

[0003] Due to the increasingly serious environmental pollution, low-carbon life has become a trend, such as integrating new energy into the grid and promoting the development of electric vehicles (EV), at the same time, the large-scale use of new energy has increased the level of power transmission, making it possible to have a DC link The AC / DC hybrid power system has become a research hotspot in recent years, and the problem of system instability caused by these needs to be solved urgently

Wind energy is one of the new energy sources mainly used for power generation. Its own characteristics also bring a series of challenges to the stable power generation of the microgrid. Traditional thermal power units cannot meet the frequency requirements. Therefore, single energy storage for frequency regulation The single energy storage system plays a vital role in the frequency regulation and economic benefits of electric vehicles. The most commonly used energy storage systems in electric vehicles are mainly energy storage batteries or supercapacitors. However, with the battery The capacity increases and the continuous use cycle shortens the life of the energy storage battery, and the cost is also increasing. The supercapacitor has the characteristics of fast response and small required capacity, but if the supercapacitor is used improperly, it will cause electrolyte leakage and other phenomena, and aluminum Compared with electrolytic capacitors, the internal resistance is large and cannot be used in AC circuits. Therefore, a single energy storage technology cannot meet the needs of electric vehicles and the frequency requirements of microgrids, and the robustness and operational stability of microgrids are still low.

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