Centralized-distributed photovoltaic intelligent power control system, photovoltaic power system and control method

Abstract

The invention discloses a centralized-distributed photovoltaic intelligent power control system, a photovoltaic power system and a control method. The intelligent power control system comprises a plurality of single string control units and a centralized control unit, wherein the centralized control unit is connected with each single string control unit, each single string control unit is correspondingly used for controlling an output power of a path of photovoltaic string, and the centralized control unit is used for synergically controlling each single string control unit to synertically control the output power of each path of photovoltaic string. The photovoltaic power system comprises a photovoltaic array, the control system and an inverter. According to the control method, each single string control unit is used for performing maximum power point tracking (MPPT) control on the corresponding path of the photovoltaic string, and the centralized control unit is used for acquiring an output power state of each path of photovoltaic string in real time and controlling and adjusting the output power of each path of photovoltaic string. The intelligent power control system has the advantages of high luminous efficiency, high reliability and the like, and intelligent optical matching and integral coordination control of photovoltaic power generation can be achieved.

Description

technical field [0001] The invention relates to the technical field of photovoltaic power generation, in particular to a distributed photovoltaic intelligent power supply control system, a photovoltaic power supply system and a control method. Background technique [0002] The solar photovoltaic power generation system is composed of photovoltaic cell module arrays, confluence power distribution, converters and other equipment. The photovoltaic cell module array includes multiple photovoltaic strings, and each photovoltaic string is composed of several photovoltaic modules connected in series. In a large-scale photovoltaic power generation system, due to the large footprint of the photovoltaic module array, there are certain differences in the output characteristics of each photovoltaic string, and may be affected by factors such as shadow shading, and the use of a single system control will lead to failure of the power generation of the photovoltaic module array. Especially...

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Problems solved by technology

[0004] However, for the distributed photovoltaic power generation system using the above-mentioned multi-string MPPT control method, on the one hand, there are certain differences in the output characteristics of each photovoltaic string in the photovoltaic array. The multi-string MPPT control method controls multiple photovoltaic strings through one MPPT, which cannot be identified. The difference between the photovoltaic strings in the parallel branch cannot balance the difference between the photovoltaic strings, so the power generation system still has the problem of photovoltaic string parallel mismatch, which affects the power generation of the system; on the other hand, each MPPT controller They are controlled independently of each other, and the photovoltaic array as a whole cannot achieve mutual coordinated control. When there is a failure of the photovoltaic string or being blocked by shadows, etc., which reduces or fails to effectively output power, it will lead to a reduction in the overall power generation efficiency of photovoltaic power generation.

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