Grid-connected and off-grid photovoltaic charging method and household energy storage system

Abstract

The invention relates to the technical field of photovoltaic charging and energy storage, in particular to a grid-connected and off-grid photovoltaic charging method and a household energy storage system. According to the method, in a grid-connected state, firstly, electric quantity information of a battery is obtained, then, when the electric quantity information is lower than or equal to a preset electric quantity threshold value, a charging system for charging the battery is determined, the charging system comprises a photovoltaic system or a power grid system, and finally, the charging system is controlled to charge the battery. By means of the mode, in the actual process of electricity purchasing and electricity utilization, a backup power supply with flexible chargeing can be selectively provided for a user, and therefore, the electricity utilization cost of the user is saved.

Description

technical field [0001] The invention relates to the technical field of photovoltaic charging and energy storage, in particular to an on-grid and off-grid photovoltaic charging method and a household energy storage system. Background technique [0002] With the adjustment and development of the energy structure of the whole society, the reduction of battery costs and the improvement of people's awareness of clean energy, household energy storage products are increasingly selected as household appliances and appear in thousands of households. The application fields of energy storage products are also becoming more and more extensive, such as being applied to homes, schools, shopping malls, hospitals, government office buildings, churches, parking lots, farms and so on. The application mode of energy storage products is usually called functional mode. Common energy storage products provide functional modes such as peak-shaving and valley-filling mode, backup power mode, matchin...

AI Technical Summary

Problems solved by technology

[0003] There is usually a difference in peak and valley electricity prices when buying electricity from the grid. The charging strategy provided by the existing technology is a fixed charging method. As long as the grid returns to normal and the remaining battery capacity is less than a certain value, the battery will be automatically replenished. It is impossible to charge the battery during the valley electricity price, and users will have to spend more money to buy electricity. Therefore, the traditional way of charging and supplying power will bring greater economic losses to end users

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