Solar photovoltaic off-grid and grid-connected multi-mode generating system

Abstract

The invention relates to solar photovoltaic generating applications, and in particular relates to a multi-mode photovoltaic generating system, wherein the multi-mode photovoltaic generating system mainly adopts off-grid power generation, and can release gird-connected power generation as for the surplus electric energy which is not consumed completely by a DC (direct-current) emergency load and storage batteries. The system comprises a controller, solar-cell arrays, a storage battery, the DC emergency load, a grid-connected inverter and a public distribution network, wherein a part of DC electric energy output by the solar-cell arrays is supplied for the DC emergency load by a DC bus, and the other part of the DC electric energy output by the solar-cell arrays is stored in the storage batteries. When the voltage of the DC bus is out of the normal range, the storage batteries supply the energy for the DC emergency load by a charge-discharge controller; and when the storage batteries finish the charging and the voltage of the DC bus is within the normal range, the surplus DC electric energy can be converted into AC (alternating-current) electric energy by a DC boost converter and a grid-connected inverter and then the AC electric energy is transmitted to the public distribution network. The system provided by the invention can improve the efficiency and the time of annual power generation of the system, and has good application prospects.

Description

technical field [0001] The invention relates to an application of solar photovoltaic power generation, especially a multi-mode photovoltaic power generation system that can mainly generate off-grid power generation, and the excess electric energy that cannot be consumed by DC emergency loads and batteries can be connected to the grid for power generation. Background technique [0002] Solar photovoltaic power generation can replace and reduce the use of limited and non-renewable coal, oil, natural gas and other primary fossil energy and the secondary energy converted from it. Promoting the application of solar photovoltaic power generation is of great significance to reducing the consumption of fossil energy and optimizing the energy structure. [0003] Solar photovoltaic power generation does not emit pollutants that damage the atmosphere and the ecological environment, and is a clean and green energy that is in harmony with the ecological environment on which human beings ...

AI Technical Summary

Problems solved by technology

[0007] However, for the off-grid power generation system, when the battery pack is fully charged and there is no electrical load, the solar cell array will not be able to generate electricity because there is no output load, and the convertible electric energy of the solar cell array will not be utilized; For the grid-connected power generation system, when the distribution network fails, in order to prevent the island effect, the grid-connected inverter will not be allowed to work, and the convertible electric energy of the solar cell array will not be used.

Images