Module Tech 06 | IV Testing Technology

After lamination, frame assembly, junction box installation, curing, and cleaning processes are completed, the module enters the IV (current-voltage) testing stage, which plays a critical role in controlling the electrical performance of the module before it leaves the factory. As the final electrical performance test before shipment, the IV test is essential. In this issue, let's take an in-depth look at the IV testing technology in Gstar's high-efficiency photovoltaic module process and explore its professional working principles.

Guardians of Module Electrical Performance

In simple terms, the IV test is a technology that uses a data acquisition and control unit to simulate lighting conditions while simultaneously collecting voltage and current data at high speed, ultimately generating an IV curve. This process not only tests the accuracy and efficiency of the equipment but also serves as a comprehensive check of the module's electrical performance.

During the test, the system generates three key IV curves:

1. 1sun curve?(curve under standard lighting conditions)

2. 0.5sun curve?(curve under half-lighting conditions)

3. Dark current curve?(curve under no light conditions)

By adjusting for light intensity and temperature, these curves allow for precise calculation of the module's main electrical performance parameters, including:

· Short-Circuit Current (Isc):?The maximum current that can be output when the voltage across the solar cell is zero, at a specific temperature and irradiance. It is a key indicator of the module's current response capability.

· Open-Circuit Voltage (Voc):?The voltage across the solar cell terminals when it is in an open-circuit (no load) state, under the same conditions, reflecting the module's maximum voltage output.

· Fill Factor (FF):?An indicator that comprehensively evaluates the module's power conversion efficiency. It is the ratio of the current-voltage product at the maximum output power point to the short-circuit current and open-circuit voltage product. A higher FF value indicates better energy conversion efficiency of the module.

To ensure the comparability and accuracy of IV test data, the industry has established a set of standard testing conditions (STC), which include a spectrum of AM1.5, light intensity of 1000W/㎡, and a room temperature of 25°C. Under this standard, the electrical performance of all modules is tested on the same basis, facilitating evaluation and comparison.

IV Testing Data: A Direct Reflection of Module Performance

Through technological upgrades, Gstar's module production lines effectively reduce the impact of contact resistance, making the test results more accurate and reliable. The performance data of the modules after IV testing is meticulously recorded in the module's specification sheet, serving as an important reference for customers when choosing products. These data not only show whether the module's electrical performance meets the standard but also directly reflect the module's actual power generation capacity and efficiency, providing users with a scientific and quantifiable performance evaluation standard.

"Excellence Made in Gstar" – the Module Tech series?has reached its sixth issue. From the introduction of laser scribing technology to detailed analyses of SMBB technology, high-density encapsulation, EL testing, automatic lamination technology, and this issue's exploration of IV testing, we have explored?the key manufacturing processes that affect module performance along the production flow. These?articles aims to deeply analyze the craftsmanship behind Gstar's high-efficiency modules and demonstrate the rigorous and high-quality requirements of each step. Going forward, we will continue to release professional interpretations of cells, wafers, and frames manufacturing technologies, further enriching the knowledge map of the photovoltaic field and providing global industry partners with professional and comprehensive insights.

?

?