Grid-connected operation control method for user side microgrid

Abstract

The invention discloses a grid-connected operation control method for a user side microgrid. On the basis of a layered-structure-based microgrid coordination control strategy, the layered structure includes a local control layer, a central control layer, and a distribution network scheduling layer. According to the invention, with study of a grid-connected operation mode in a microgrid, on the premise that the electric energy quality is guaranteed, the power generation advantages of all micro sources are fully utilized and coordinated control is carried out on various micro sources in a user side micrgrid efficiently and reliably, thereby meeting requirements of energy balancing and outputting of the microgrid. The method is suitable for coordinated control between multiple power sources, distribution networks, and loads on various operation working conditions. The method is simple and practical. The internal voltage and frequency of the microgrid become stable; the safety operation of the important load is guaranteed; and the impact on the large power grid is reduced. Meanwhile, the output of the photovoltaic power generation system can be fully utilized and the utilization rate of the renewable energy source is improved.

Description

technical field [0001] The invention relates to the technical field of micro-grids, in particular to a method for controlling grid-connected operation of micro-grids. Background technique [0002] With the gradual depletion of fossil energy and the increasing environmental pollution, the development and utilization of clean energy and renewable energy has become an inevitable choice. Renewable energy such as solar energy and wind energy has been rapidly developed and widely used in the world. At the same time, with the rapid development of industrial civilization, the demand for electricity is increasing day by day, and the scale of traditional power grids continues to expand. Ultra-high voltage and long-distance centralized power transmission methods are facing more and more challenges. Based on the above background, Distributed Generation (Distributed Power Generation) Generation, DG) technology has been widely concerned and valued by researchers at home and abroad. The d...

AI Technical Summary

Problems solved by technology

When the large grid is disturbed, by removing the microgrid and eliminating the influence of the microgrid on the frequency fluctuation of the large grid, the frequency of the large grid can be quickly restored and the security of the large grid can be improved. However, this method does not fully consider the internal state of the microgrid. It is also impossible to maximize the output of photovoltaic power generation

In addition, (A microgrid system and energy control method for grid-connected and off-grid operation, Chinese Patent No.: 201310618109.7) proposes a grid-connected operation control method, which detects the SOC (State of Charge, state of charge), control the supercapacitor to correct the charge and discharge state of the battery, and exchange energy between the microgrid and the distribution network through the central controller, energy control device, and load controller to make it run stably, but the control The coordination of the device is very demanding

Existing micro-grid coordinated control strategies have their own advantages and disadvantages, and it is difficult to popularize and apply them on a large scale, and there are few researches on grid-connected operation.

Images