Fully Integrated and System-Optimized Electronic Solutions on Solar Modules

Alternating-current (AC) PV modules offer various advantages such as easier installation, safer operation and increased efficiency for residential and building-integrated PV systems including small balcony power plants. Although there is a growing market for module level electronics, there are still only limited solutions available. Here, we present the combination of different innovations to raise the potential of simplification and synergies by fully integrating the power electronics into the PV module. We developed a novel, highly efficient and compact power electronics with galvanic isolation offering a fully reactive power-capable inverter topology, utilizing 650 V gallium nitride power semiconductors. The communication is enabled by wireless communication based on Wirepas mesh connectivity, allowing a safe and robust operation and flexible expansion of the PV system. The module electronics are connected directly to the cross-connectors of the PV modules, allowing for novel circuit configurations to omit conventional bypass diodes and to be a cost-effective approach of limiting the operating range of each substring to prevent hot spot events on the module without significant yield losses. Furthermore, a slot antenna is introduced into the cross-connectors of the PV module. The antenna is capacitively fed through the backsheet by an aperture coupling printed circuit board on the rear side of the module. The fully integrated electronics are attached to the PV module, encapsulated and electrically isolated from the environment by low-pressure molding, which has shown high reliability in accelerated aging tests. All these key components are combined in demonstrators based on full-sized PV modules that are installed and operated on an outdoor test stand and prove the functionality of the combined components.