Smart photovoltaic grid-connected box with grid voltage stabilizer

Abstract

The invention discloses an intelligent photovoltaic grid-connected box with a power grid voltage stabilizer, relates to the technical field of photovoltaic power equipment, and aims to solve the problem that the loss of an inverter and other devices is further increased caused by voltage instability due to many factors in the existing low-voltage power distribution system. The intelligent photovoltaic grid-connected box is technically characterized by comprising a direct current confluence device, an inverter device and an alternating-current grid-connected device; the alternating-current grid-connected device comprises an inverter alternating-current input unit, a grid-connected load output unit and a voltage-stabilizing unit, wherein the two ends of the voltage-stabilizing unit are connected with the inverter alternating-current input unit and the grid-connected load output unit through a switching switch separately; two paths of sampling circuits and voltage zero-crossing detectioncircuits of the same structures are set to collect alternating-current voltage parameters of the commercial power and the inversion voltage parameters of a photovoltaic inverter respectively; and next, the two paths of voltage zero crossing points are detected, and then comparison, feedback and amplification are carried out according to the data obtained by sampling, so that the position of a carbon brush of a voltage regulator is changed, the feedback of the turn-to-turn ratio of coils is adjusted to change the voltage, and the output voltage is kept stable.

Description

technical field [0001] The invention relates to the technical field of photovoltaic power equipment, in particular to an intelligent photovoltaic grid-connected box with a grid voltage stabilizer. Background technique [0002] Today, when the country vigorously advocates energy conservation and emission reduction, and develops renewable energy, photovoltaic power generation technology is widely used. It is a new power generation technology that uses the photovoltaic effect of solar cell semiconductor materials to directly convert solar radiation energy into electrical energy. There are two modes of independent operation and grid-connected operation. Grid-connected operation means that the alternating current generated by the photovoltaic array is converted into alternating current that meets the requirements of the public grid through the grid-connected inverter and then directly connected to the public grid. [0003] The operation of the grid-connected inverter in the photo...

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Problems solved by technology

[0003] The operation of the grid-connected inverter in the photovoltaic system needs to match the grid voltage. In the traditional three-phase four-wire low-voltage power distribution system, there will be many factors that lead to voltage instability, such as zero disconnection, the end of the distribution line, etc. The voltage is too low, the end of the no-load line voltage is too high, etc., all of which will increase the loss of the inverter and other devices, and when the voltage fluctuates greatly, the protection device will be shut down to reduce the power generation, and even the voltage will continue to fluctuate. As a result, the protection device fails and damages the photovoltaic power generation device

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