Distributed photovoltaic power station system and reactive self-balancing control method

Abstract

The invention discloses a distributed photovoltaic power station system and a reactive self-balancing control method. The system comprises a photovoltaic power generation system, the photovoltaic power generation system comprises a photovoltaic module, a grid-connected inverter, a photovoltaic transformer and an access module which are connected in sequence, and the output end of the access module is connected to a user low-voltage power distribution system. The system further comprises a reactive self-balancing control device connected with the photovoltaic power generation system, and the reactive self-balancing control device collects a plurality of voltage and current signals at the access module within a specified time length, calculates a corresponding power factor, determines a target power factor according to each calculated power factor and sends the target power factor to the grid-connected inverter to control the grid-connected inverter to operate according to the target power factor. The system has the advantages of being simple in structure, low in cost, capable of achieving reactive self-balance and improving the power factor of a gateway point, good in reactive adjustment control effect and the like.

Description

technical field [0001] The invention relates to the technical field of distributed photovoltaic power stations, in particular to a distributed photovoltaic power station system and a reactive power self-balancing control method. Background technique [0002] Distributed photovoltaic power stations are mostly built in industrial factories or business parks, and use medium and low voltage to connect to the user grid. The power generated is mainly for self-use and consumption nearby, and the remaining power is connected to the grid. During the operation of distributed photovoltaic power plants, there are often prominent power factor problems. For example, the power factor of the distribution gateway in the factory area is unqualified, which increases the power factor to adjust the electricity bill. Some photovoltaic power plants are even forced to shut down. Both users and power generation companies have caused economic losses that cannot be ignored. The main reasons for the u...

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Problems solved by technology

[0006] However, in the actual application of the above-mentioned traditional inverter power factor adjustment scheme, it is impossible to guarantee the sequence of the reactive power adjustment of the photovoltaic inverter and the switching of the low-voltage capacitor. In the process, the inverter first outputs reactive power. When the reactive power output of the inverter reaches the upper limit, the low-voltage compensation capacitor is put into operation; Before the upper limit is reached, the capacitor has no chance to be put into operation again, that is, the reactive power regulation of the inverter will have the same effect as the capacitor regulation, and the fine-tuning of the inverter on the basis of capacitance compensation cannot be realized. The above regulation scheme is usually used in practical applications. is invalid and cannot achieve the desired adjustment effect

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