A control method of grid-friendly distributed power generation based on hybrid energy storage

Abstract

The invention provides a control method of a grid friendly type distributed power source based on hybrid energy storage. The method comprises the steps of optimally designing a topology structure of the distributed power source, controlling a direct current power supply system in a coordinating mode through a direct current (DC) / DC converter controlling a model normalization model, and self-adaptively controlling a grid of an alternating current (AC) side DC / AC converter. The distributed power source not only can be connected in a large grid to operate so as to reduce the influence of intermittent renewable energy power generation grid connection on the grid and provide support of voltage and frequency for the grid, but also can be connected into a micro-grid to operate as a network unit of the off-network type micro-grid to maintain stability of voltage and frequency of the off-network type micro-grid. When an outer grid breaks down, the distributed power source can realize switch between a grid mode and an island mode so as to improve power supply reliability of important loads in the system. The distributed power source improves technical performance and economic performance of the whole system through matching utilization of an energy type system and a power type energy storage system.

Description

technical field [0001] The invention relates to the operation and control of distributed power sources, in particular to a control method for grid-friendly distributed power sources based on hybrid energy storage. Background technique [0002] To realize the grid-friendly characteristics of distributed power generation based on hybrid energy storage, the control strategy of the AC side converter of distributed power generation and the effective utilization of hybrid energy storage are key technical issues that need to be solved. [0003] (1) Distributed power supply control strategy [0004] Intermittent renewable energy power generation, especially wind power and photovoltaic power generation, has the characteristics of intermittent, fluctuating and uncontrollable output. If it is connected to the grid, it will have a series of impacts on the security and stability of the grid. In order to reduce the impact of renewable energy generation grid connection on the grid, the re...

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Problems solved by technology

In order to obtain a stable DC bus voltage, some literature proposes a hybrid energy storage structure in which a supercapacitor is connected in parallel with a battery pack through a DC / DC converter. Although the DC bus voltage is relatively stable during power fluctuations, this structure cannot be achieved. The flexible management of the input and output energy of the battery pack cannot give full play to the role of various types of energy storage devices

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