During the application process of photovoltaic modules, they face various harsh environmental conditions, such as high temperature, high humidity, long-term moisture penetration, etc. Simulating these harsh environmental conditions through damp heat testing can ensure the reliability and durability of the modules. The Damp Heat Test Chamber from Millennial Solar complies with IEC international standards and related content, and can provide real and reliable test results for photovoltaic modules. Provide important reference for design and production.

Effect of excessive formation of acetic acid on photovoltaic modules under damp heat test

In order to distinguish the durability of photovoltaic modules, long-term damp heat tests are often performed. The picture below shows five photovoltaic modules tested at 85°C and 85% relative humidity (RH) for 5 times for 1000 hours, using thermoplastic M1 and elastomer sealant M2-M5, 1000 hours at 85°C and 85 % relative humidity, heat and humidity cycle, module power loss fraction obtained through stress test.

Figure 1

Four PV module types showed severe degradation after 2000h due to increased silicon contact resistance due to fill factor (FF) loss due to metallization. Under test conditions, temperatures and humidity greatly exceed those found in PV module installations, and the degradation mechanisms observed through such testing are often inconsistent with those observed in the field. Aggregated field degradation data on crystalline silicon cell modules indicate that degradation is primarily caused by short-circuit current losses, followed by FF losses, with open-circuit voltage showing minimal degradation.

Excessive humidity may result in excessive acetic acid formation, which can lead to unrealistically high FF losses, through grid line contact corrosion and other mechanisms. As shown in the figure below, if after 2000 hours of damp heat testing, the assembly is transferred to a damp heat environment with a target module temperature of 85°C for UV irradiation, the power loss is more modest.

Figure 2

The study proposes a sequential test sequence as shown in Figure 3, taking into account the relative levels seen in outdoor exposure, in addition to the moist heat and moist heat with UV sequences, including temperature cycling, which increases thermo-mechanical fatigue stress.

Figure 3

Due to the formation of acetic acid, on the front side of the cell, when alternating between moist heat in the dark (bringing moisture into the module) and UV moist heat (drawing moisture out of the module, just like lighting in photovoltaic modules) Humidity levels in the alternating sequence were shown to stabilize at about 30% lower than in the continuous hygrothermal case, reducing the formation of unrealistically large amounts of acetic acid that could affect the metallized silicon contacts of some solar cells.

Damp Heat Test Chamber

E-mail: market@millennialsolar.com

Introduce:

Photovoltaic modules will withstand various harsh weather tests during their application. Among them, the performance of components such as their ability to withstand high temperatures, high humidity, and long-term moisture penetration needs to be evaluated. Hot and humid environment simulation tests are used to verify and evaluate the reliability of photovoltaic modules or materials, and to identify manufacturing defects early through thermal fatigue-induced failure modes.

Fulfill the standard:

IEC61215-MQT13; IEC61730-MST53

Features:

Continuous operation for more than 1,000 hours at 85°C and 85%RH requires ultra-high stability. The Damp Heat Test Chamber developed by Millennial is very high-quality in terms of manufacturing process and electronic equipment reliability.

•Built-in circulating air duct and long-axis ventilator for effective heat exchange, making the temperature inside the environmental box uniform and stable

•Adopt imported temperature controller to realize multi-stage temperature programming with high precision and good reliability

•Can operate in continuous high temperature and high humidity environment, and can also conduct high and low temperature interactive tests according to the engineering staff's plan

•With a potential-induced degradation testing machine, the performance of photovoltaic modules can be observed more intuitively

•Temperature fluctuation: ±0.5℃

•Humidity fluctuation: ±2.0%RH

Damp Heat Test Chamber can be used with Potential Induced Degradation (PID) Tester

E-mail: market@millennialsolar.com

Introduce:

Long-term leakage current will cause changes in the state of the cell carriers and depletion layer, corrosion of the contact resistance in the circuit, and electrochemical corrosion of the packaging materials, resulting in cell power attenuation, increased series resistance, and reduced light transmittance. , delamination and other phenomena that affect the long-term power generation.

Fulfill the standard:

IEC61215-MQT21; IEC62804

Features:

•The frame end of the module is grounded, which not only simulates the actual situation, but also prevents potential dangers caused by high voltage on the frame;

•Each channel is independent of each other, and the voltage size, polarity and time of multiple channels can be set independently;

•Multiple voltages, leakage current, and insulation resistance are displayed simultaneously;

•Real-time monitoring of voltage, leakage current, and insulation resistance curves;

In the development of the photovoltaic industry, Damp Heat Test Chamber is becoming more and more widely used. It is an important tool for photovoltaic module manufacturers to conduct product certification and quality control, ensuring the reliability of modules under various climatic conditions, thereby improving the life and performance of the system. The Damp Heat Test Chamber from Millennial Solar follows international standards to provide more effective guarantee for the quality and reliability, helping achieve the best energy production and return.