GB/Z 118.1-2026Photovoltaic modules - Extended-stress testing - Part 1: Modules (English PDF)

Foreword

This document is a standard or guiding technical document.

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents". Drafting.

This document is Part 1 of GB /Z 118 "Photovoltaic Modules - Enhanced Stress Testing". GB /Z 118 has already published the following parts.

---Part 1: Components.

This document is equivalent to IEC TS63209-1:2021 "Photovoltaic modules - Stress testing - Part 1: Modules", and the document type is changed from... The IEC technical specifications have been adapted into my country's national standardization guidance technical documents.

Introduction

GB /Z 118 proposes a method for environmental stress testing of photovoltaic modules, which can provide data for evaluating the reliability of photovoltaic modules and facilitate research.

Areas not covered by the GB/T 9535 and GB/T 20047 series. GB /Z 118 is proposed to consist of the following parts.

---Part 1: Components. The purpose is to provide a checklist for enhanced environmental stress testing of photovoltaic modules.

---Part 2: Polymer Component Materials. This section aims to supplement component-level reinforcement environmental stress testing.

Note: The correspondence between each part and the IEC TS63209 series of international standards is as follows.

---Part 1 corresponds to IEC 63209-1;

---Part 2 corresponds to IEC 63209-2.

Existing qualification test standards, such as the GB/T 9535 series, are for identifying component designs to avoid most early field failures.

These qualification test standards are often useful, but they are not intended to, or cannot, prove the long-term performance of components at all locations within the scope of the standard documentation.

Performance. To assess the risk of product failure, industry practice dictates that type approval be performed according to the GB/T 9535 and GB/T 20047 series of standards.

Based on safety testing, more stringent testing protocols can be implemented to meet the needs of different stakeholders. These enhanced stress tests The agreement primarily includes the aforementioned basic tests, conducted with different sequences and/or increases in test time or number of cycles. The stress testing agreement... The discussion stems from diverse experiences shared by third parties, such as testing agencies, independent engineering firms, and homeowner engineers, aiming to replicate the effects of long-term use on photovoltaic modules.

These stress testing protocols, or "extreme testing" methods, are designed to identify module weaknesses rather than reproduce the module's outdoor performance.

It does not provide detailed reliability or durability predictions/estimates, but it is helpful in revealing defects.

Given that many different stress testing protocols are in use, the industry needs a standardized approach. This document contains... The included stress-enhancing test sequence standardizes various methods used by personnel in different industries, providing a universal method for reliability assessment.

The dataset. In practical terms, this document addresses the challenges faced by component manufacturers in simultaneously implementing (and maintaining) a series of [issues/processes] after product changes. The problem lies in very similar testing protocols.

This global reference comparison document takes into account all sequences of different stress-enhancing testing protocols and was prepared using the method of common divisors. (Targeting...)

Each subsequence also has its corresponding special failure mode added at the appropriate position. Meanwhile, some sequences have been deleted from this document, according to their experimental... Results obtained from conditions and durations do not necessarily provide information for evaluating component performance in the field. This document aims to standardize and strengthen testing protocols.

Test results from different institutions can be compared more directly, reducing testing costs and time for manufacturers.

This document aims to provide a series of reliability risk data for qualitative analysis, highlighting potential failure modes of components and the possible reasons for failure.

Improved areas. This method is only used in special cases, such as when performance differences are very large or when targeting specific known failure modes and mechanisms, for [specific applications].

Components and materials are classified. Classification or lifespan prediction for durable components is not within the scope of this document. A range of components.

1 Scope

This document aims to provide information to supplement the basic qualification tests with pass-fail criteria defined in GB/T 9535.

The document provides a standardized testing methodology for evaluating photovoltaic (PV) modules and a list of different materials that can be used to manufacture these modules.

The long-term reliability of (BOMs). The test sequences included in this document are intended to provide information for qualitative comparative analysis, and are used in conjunction with outdoor exposure. The relevant stresses are used to reproduce known failure modes.

Considering that if the experiment takes too long, users will make a decision before receiving the results, therefore the experiment duration... This is a significant limitation. Under the aforementioned commercially relevant limitations, some known failure modes, especially those associated with prolonged ultraviolet (UV) exposure, are... Issues related to sunlight cannot be accurately addressed. Although UV stress-related failure modes are known to occur on both the front and back of photovoltaic modules, However, without applying excessive stress, the UV stress dose required to generate outdoor variations within the expected lifespan of the component is... The test duration was excessive and exceeded the scope of this document. The UV stress sequence for the air-faced backplate included in this document has been supplemented with information regarding certain backplate air-faced backplates.

The confidence level for surface cracking failure is given, but the UV stress sequence of the backsheet battery surface is not included in this document at all, leading to the corresponding failure mode.

Missing features include, for example, discoloration of the encapsulating film, cracking of the battery surface on the backplate, and delamination of the battery surface.

Appendix A describes other limitations of the enhanced stress test. This document identifies the weaknesses of the component and does not attempt to gather information for lifetime prediction.

The necessary information for lifetime prediction includes identifying component failure mechanisms and their correlation with all stresses. Appendix B contains... A brief background on the origin of the experiment.

This document should not be used as the basis for pass/fail determination. The same component applied in two different locations may be used in different ways.

Failure/aging means that a single testing protocol cannot be expected to perfectly match both outcomes simultaneously; it will depend on the application location and method. Furthermore, Both missed and incorrect tests can occur. due to the high acceleration and intensification of some stress exposures, testing can cause components designed for outdoor use to fail.

Changes that won't occur will be missed, while some aging processes that are difficult to accelerate will be overlooked.

As reflected in the target failure modes, this document is primarily written for crystalline silicon photovoltaic modules. However, the stress applied in the experiments... Based on the real-world usage environment of the components, this approach is also applicable to most photovoltaic modules. The interpretation of data obtained from experiments should always include design variations.

This can further increase the likelihood of new failures. In particular, components with different structures (e.g., without a standard glass front panel) can be observed to exhibit different... The method failed. In summary, analyzing the data collected during the enhanced stress testing procedure as input information can identify whether additional testing is necessary.

This allows for a more comprehensive evaluation of the component's performance in relation to the intended application conditions.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 9535-2025 Design Qualification and Type Approval of Ground-Mounted Photovoltaic Modules Part 1-1.Characteristics of Testing Crystalline Silicon Photovoltaic Modules Special requirements (IEC 61215-1-1:2021, IDT)

GB/T 9535.2-2025 Design qualification and type approval of terrestrial photovoltaic modules - Part 2: Test procedures (IEC 61215-2) 2021, IDT)

IEC TS60904-1-2 Photovoltaic devices - Part 1-2.Measurement of current-voltage characteristics of bifacial photovoltaic devices