Double-level synchronous control method for parallel weak power grid type electricity-hydrogen coupling direct current micro-grid

Abstract

The invention discloses a double-level synchronous control method for a parallel weak power grid type electricity-hydrogen coupling direct-current micro-grid. In top-level optimization control ,the equal-year-value operation cost of a minimum system life cycle is taken as a control target, and an optimal output power reference value of an electricity-hydrogen hybrid energy storage system is obtained through a path-finding meta-heuristic algorithm; and in bottom-level optimization control, an improved niche genetic algorithm is adopted to solve an optimal tracking virtual resistor meeting multi-target control of minimum electric energy quality deviation and stabilization time on line, and the solved optimal value is utilized to control a DC / AC grid-connected inverter; and due to the fact that an optimized main body and an optimized object are different, optimization at two levels can be carried out synchronously, and in addition, the working mode of the electricity-hydrogen hybrid energy storage system is determined by the optimal power reference value of the top layer. The optimal economic operation of the micro-grid can be realized under the conditions of renewable energy power fluctuation and weak grid impedance change, the stability of the micro-grid is enhanced, and the application scene of the electro-hydrogen coupling direct current micro-grid is expanded.

Description

technical field [0001] The invention belongs to the technical field of DC micro-grids, and in particular relates to a double-layer synchronous control method of an electric-hydrogen coupled DC micro-grid with parallel and weak grids. Background technique [0002] At present, my country's cumulative installed capacity of wind power and photovoltaic power generation ranks first in the world, and the scale of clean energy power generation continues to expand. With the development and utilization of renewable energy, distributed power generation has become an important form of renewable energy access system. The output power of independent distributed power is fluctuating, intermittent and random, and direct access to the power grid will affect its reliability, economy and safety, so micro-grid technology has received extensive attention. In order to maximize the utilization of renewable energy, the combination with the energy storage system will improve the ability to absorb r...

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Problems solved by technology

[0003] The existing control methods for integrating the microgrid into the weak grid can be divided into two types: improved grid-connected inverter control loop and active damper, but the former will redesign the modularized inverter control loop, which will increase The design cycle and reduce the adaptability of the grid-connected inverter to other grid-connected objects; the latter method requires the installation of active dampers, which will greatly expand the system area and increase the cost; and most of them focus on how to realize The stable operation of grid-connected inverters has not been discussed in combination with actual micro-sources. In particular, the coordinated operation of the overall power of the micro-grid in this case has not been explored, which leads to the application of actual DC micro-grids into weak grids. There are multiple limitations

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