An inverter device for photovoltaic power generation

Abstract

The invention discloses an inverter device for photovoltaic power generation, which has an electric meter terminal and a load terminal, and the electric meter terminal is used for connecting with a bidirectional electric meter. The inverter device comprises an inverter part which converts the direct current generated by the photovoltaic module into a sine wave alternating current. A first switch connected between the meter terminal and the load terminal; a second switch connected between the inverter portion and the load terminal; an inverter control section connected to the inverter section,the first switch and the second switch; First synchronization unit, which is connected to a meter terminal and an inverter control unit, and the inverter control section is further configured to control the inverter section to operate in the grid-connected mode or the off-grid mode according to whether or not the first synchronization signal satisfying a predetermined requirement is received within a predetermined time after the start of the operation, and to transmit the first synchronization signal to the inverter control section when it is detected that the power network is in the power supply state. The inverter device of the invention can be switched between a plurality of working modes to reasonably and efficiently utilize the electric energy generated by the photovoltaic module.

Description

technical field [0001] The invention relates to the field of photovoltaic power supply, in particular to an inverter device for photovoltaic power generation. Background technique [0002] When the power obtained by photovoltaic modules converted from solar energy is transmitted to the grid, it is usually necessary to use an inverter to convert the DC power generated by the photovoltaic modules through DC / DC conversion and DC / AC conversion, and then transmit the alternating current obtained through inversion to the grid. middle. [0003] figure 1 It is a structural schematic diagram of an existing photovoltaic power supply system, which illustrates the connection mode among photovoltaic modules, inverters and grids. like figure 1 As shown, the owner of the photovoltaic module needs to first convert the power generated by the photovoltaic module into alternating current through the grid-connected inverter and then transmit it to the grid, and connect the local loads that n...

AI Technical Summary

Problems solved by technology

[0004] However, since the owners of photovoltaic modules earn far less from electricity sales per kilowatt-hour than the electricity purchase expenses per kilowatt-hour, it will take at least ten years to recover the investment in building a photovoltaic power supply system based on the existing photovoltaic power supply model.

Although the life of solar panels can reach 25 years, considering that the photovoltaic power supply system also requires maintenance costs during operation, the owners of solar panels can get very little return during the life cycle

It is also very impractical to rely on state subsidies to develop and popularize the photovoltaic system of the existing power supply mode.

[0005] figure 1 Another disadvantage of the grid-connected inverter in the prior art shown in is that once the power grid fails, it cannot continue to work, nor can it realize multi-machine joint power supply

[0006] If the existing photovoltaic power supply is improved according to the micro-grid architecture in the prior art (for this technology, please refer to the patent document with the application number 20101041039.7 and the invention name "a household multi-energy system and its control method") system, its complexity and correspondingly increased costs are difficult for photovoltaic system owners to accept

Images