PV module pid level test method and test system for setting water film thickness

Abstract

The invention discloses a PV component PID horizontal test method and system with a set water film thickness. A water blocking dam is arranged on the periphery of the boarder of a light reception surface of a tested PV component; an overflow gap is formed in the side wall of the water blocking dam, wherein the distance between the bottom edge of the overflow gap and the light reception surface of the tested PV component is the set water film thickness; the tested PV component is horizontally placed in a water channel, wherein the light reception surface of the tested PV component faces upward; the water channel containing the tested PV component is horizontally placed in an environmental test chamber; the environmental test chamber is started, and high voltage loading equipment applies a voltage on the tested PV component; thermostatted water is dripped on the light reception surface of the tested PV component continuously to form a water film, and when the water film thickness is kept at the set water film thickness, the high voltage loading equipment and the environmental test chamber are set to be switched off after the water film thickness lasts for a set time. The PV component PID horizontal test method and system with the set water film thickness take into account the influence on PID tests of the formation of the water film and the water film thickness, enable the test environment to be more close to an actual application environment, and improve the accuracy of PID test results.

Description

technical field [0001] The invention relates to the field of photovoltaic solar PV module testing, in particular to a method for testing the PID level of a PV module for setting the thickness of a water film, and also relates to a testing system using the testing method. Background technique [0002] In recent years, PID (Potential-induced Degradation) has become one of the important factors for power plant quality complaints. In severe cases, it can cause the power of a component to attenuate by more than 50%, thus affecting the power output of the entire power plant. At present, many companies and research institutions around the world have conducted a comprehensive analysis of the PID phenomenon of PV modules, but so far, the failure mechanism is still unclear. [0003] In 1978, Hoffman and Ross introduced the bias voltage stress factor for the first time in the environmental type test of terrestrial solar cells and modules. In 2005, Sunpower found that the long-term hig...

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Problems solved by technology

In 2005, Sunpower found that the long-term high voltage of the module caused leakage current between the glass and the packaging material, and a large amount of charge accumulated on the surface of the battery sheet, resulting in deterioration of the passivation effect of the battery surface, resulting in a decrease in FF, Isc, and Voc, making the Component performance below design requirements

At present, when using the environmental test chamber to conduct PID tests on PV modules in China, the modules are placed vertically in the environmental test chamber. Although the environmental temperature and humidity conditions of the environmental Vertical placement does not take into account the influence of the water film formed on the surface of the glass plate of the module and the thickness of the water film on the PID test, so the test conditions and severity are different when the PV module is placed vertically and horizontally. same, resulting in different test results, making the existing PID test unable to reflect the actual situation more accurately

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