Phase 1: Module Level Power Electronics Reliability and Accelerated Testing Standards Development

Project: Research project

Description

Introduction In order to make photovoltaics (PV) cost competitive with traditional energy sources, the economies of scale have been guiding inverter design in two directions: large, centralized, utility-scale (~500 kW) inverters vs. small, modular, module level (~200 W) power electronics (MLPE). MLPE, such as microinverters and DC power optimizers, offer advantages in safety, system operations and maintenance (O&M), energy yield, and component lifetime due to their smaller size, lower power handling requirements, and module-level power point tracking and monitoring capability. However, they suffer from two main disadvantages: first, depending on array topology (especially the proximity to the PV module), they can be subjected to more extreme environments (i.e. temperature cycling) during the day, resulting in a negative impact to reliability; second, since solar installations can have tens of thousands to millions of modules (and as many MLPE units), it may be difficult or impossible to track and repair units as they go out of service. Therefore, the statistical reliability of each device and the extension of unit lifetime are of critical importance to the O&M schemes of large solar installations. While an overwhelming majority of time and research has focused on PV module efficiency and reliability, these issues have been largely ignored for the balance of system components. As a relatively nascent industry, the PV power electronics industry does not have the extensive, standardized reliability measuring accelerated lifetime tests (ALTs) that exist in the module industry or other more mature power electronics industries (e.g. automotive). By recommending standard ALTs that have been thoroughly correlated to fielded MLPE failure rates, modes, and environmental stressors, the confidence of system operators, integrators, manufacturers, and financiers is increased, decreasing the cost of financing and operating large solar installations. In order to accomplish this goal, (SNL) National Laboratories is leading a team of research institutions that will carry out work in six different task areas over the 3 year time period of this project. These tasks include: 1. Formation of a MLPE reliability working group (WG) 2. Physics of field-failure determination and accelerated test plan development 3. Accelerated testing and correlation to field reliability 4. Dissemination of results in stakeholder meetings and conferences 5. Submission of recommended reliability standard protocol to standards development organizations (SDOs)
StatusFinished
Effective start/end date12/10/133/9/15

Funding

  • DOE: National Nuclear Security Administration (NNSA): $162,500.00

Fingerprint

Power electronics
Testing
Electronics industry
Security systems
Costs
Industry
Repair
Physics
Topology
Monitoring