Photovoltaic power generation system online IV curve test device and test method

Abstract

The invention discloses a photovoltaic power generation system online IV curve test device and a test method. The online IV curve test device comprises a temperature acquisition system, a solar irradiance gauge, a multi-channel photovoltaic assembly IV tester, an industrial control computer, a switch, a host computer and a switching case. According to the online IV curve test device, a relay with relatively low cost and having no arc discharge is employed to switch photovoltaic assemblies, IV curves of the assemblies are respectively tested through rapid scanning, accurate volt-ampere characteristics of the photovoltaic assemblies are acquired, and the online IV curve test device satisfies online IV curve tests on all channel assembly strings through cascade networking at present. Through the method, after switching one assembly at each time, an output voltage of the residual assembly string is guaranteed to be greater than the lowest input work voltage of an inverter, and a cell input power is further guaranteed to be greater than a normal start power of the inverter. The whole test period of rapid assembly switching, rapid IV curve scanning test and rapid switching recovery is controlled to be quite short, the online IV curve test function is realized.

Description

technical field [0001] The invention relates to the field of photovoltaic power generation system testing, in particular to an online IV curve testing device and testing method for a photovoltaic power generation system. Background technique [0002] Photovoltaic power generation systems are usually composed of photovoltaic modules, strings, combiner boxes, inverters and other equipment. The number of components varies, usually ranging from 8-12 or more. In the construction of a power station, multiple photovoltaic strings are connected to a combiner box for confluence and then connected to the inverter. The inverter will control the output power of the photovoltaic strings to the maximum through the maximum power point tracking circuit to achieve the power generation efficiency of the photovoltaic array. control. If the maximum power points of the photovoltaic strings in the array are inconsistent or there are components with poor performance, the output power of the inve...

AI Technical Summary

Problems solved by technology

This patent realizes the online test function, but it cannot scan the entire IV curve

[0008] At present, the IV curve test of the photovoltaic power generation system must disconnect the back-stage inverter, and then dismantle the photovoltaic modules one by one to measure the IV curve one by one. The test workload is huge and the power generation revenue during the test is sacrificed; Data collected at a fixed point in the IV curve by a voltage sensor or a current sensor cannot truly reflect the actual power generation performance of the module

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