Microgrid nickel-metal hydride battery energy storage system

Abstract

The invention provides a microgrid nickel-metal hydride battery energy storage system. A plurality of nickel-metal hydride battery cupboards which are electrically connected in parallel, a parallel connection control cabinet, an energy conversion system, an alternating-current distribution cabinet and the mains supply are electrically connected in sequence in a bidirectional mode. The alternating-current distribution cabinet is further electrically connected with an electrical load side in a unidirectional mode and also electrically connected with a charging / discharging machine in a bidirectional mode. A battery management system is connected with an energy management system, the nickel-metal hydride battery cupboards, the parallel connection control cabinet, the energy conversion system and the charging / discharging machine in a bidirectional mode. The alternating-current terminal of the energy conversion system is connected with the mains supply through the alternating-current distribution cabinet. According to the microgrid nickel-metal hydride battery energy storage system, large-scale parallel connection of the battery cupboards can be realized by means of coordinated management and control of the parallel connection control cabinet and the battery management system, and the safety and reliability problems that a single battery is low in capacity and is difficult to apply in a large-scale parallel connection mode, maintain in an equalized mode, and utilize with high efficiency are well solved.

Description

technical field [0001] The invention relates to a micro-grid nickel-metal hydride battery energy storage system mainly used in urban buildings, parks, communities and other buildings. Background technique [0002] Urban economic development has caused a series of social problems, such as population growth, energy crisis, environmental pollution, natural disasters, etc., among which the shortage of electricity in cities is particularly serious. [0003] The problem of urban electricity consumption is manifested in the following aspects: urban electricity shortage, large-scale power outages and power shortages, high carbon emissions; mismatch between planned electricity consumption and power generation, and uneven electricity load periods, resulting in contradictions between supply and demand and resources. Waste; the proportion of new energy applications is low, such as the low proportion of wind energy and solar energy connected to the grid, while the consumption of the grid...

AI Technical Summary

Problems solved by technology

However, battery energy storage systems also have high costs, requiring a large number of batteries to be connected in series and parallel to achieve large-scale energy storage and release capabilities, and more complex management and balancing are required to improve the safety and reliability of battery energy storage systems

[0007] High-capacity single cells are used to reduce the number of series-parallel connection of single cells in the battery energy storage system, but the high-capacity manufacturing of single cells is a big problem, and the consistency between the single cells is often poor; the use of two-way DC-DC solves the problem of indirect parallel connection after single batteries are connected in series to form a high-voltage battery string, but the introduction of bidirectional DC-DC reduces the efficiency of the battery energy storage system, and the parallel connection between bidirectional DC-DC also exists The problem of current sharing and control; use the BMS (battery management system) to set up a balance management module to manage the battery energy storage system to charge or discharge in a balanced way, so as to maintain the relative consistency between the single batteries and ensure the battery energy storage system It can provide the function of energy storage and release, but this method often brings about the problems of high balance management cost and low balance efficiency

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