Modular string inverter system for energy Storage

LS Energy Solutions‘s AiON-SIS is a modular string inverter system designed for energy storage applications that require flexible configuration, compact architecture, and scalable power conversion.

As the company’s third-generation string inverter for energy storage, AiON-SIS combines high power density, broad voltage compatibility, and patented AC- and DC-side paralleling to support a wide range of front-of-the-meter and behind-the-meter applications.

Built around independent 140kVA building blocks, AiON-SIS can be right-sized to match project power requirements. Its patented ability to parallel on both AC and DC sides allows it to operate as a string inverter or be configured into a central string inverter, giving customers the advantages of both approaches in a single platform.

AiON-SIS operates from 620VDC up to 1500VDC, making it compatible with most current and future energy storage technologies. Available in 400 AC, 480VAC, and 600VAC variants, the air-cooled inverter is suitable for a wide range of project sites and can operate in environments up to 55°C with derating.

Its compact 19-inch rack-mount design and front-mounted touch-safe parallel connections simplify integration into complete solutions. AiON-SIS can be installed in the same rack structure as most batteries or placed in a separate rack, giving system designers added flexibility.

The modular architecture also delivers important performance and safety benefits. Dividing the DC bus into multiple manageable DC busses helps reduce short-circuit currents, enhance safety, and lower system cost, while also enabling energy and power augmentation as project needs evolve. Smaller, independent strings of batteries and inverters on separate DC busses can improve system availability, support flexible layouts, and make expansion or maintenance easier over time.

For advanced applications, optional grid-forming capability makes AiON-SIS suitable for use cases including microgrids. The platform supports Modbus TCP communications and high-speed inverter-to-inverter links for precise synchronization during grid-following and grid-forming operation. Auxiliary fan power is separated from control power so control circuits can be connected to a UPS, keeping communications and control operational during power outages and supporting black start operation and inverter health monitoring.

AiON-SIS is designed for indoor applications with touch-safe lug-type terminations and a NEMA 1/IP20 rating. LS Energy Solutions backs the system with commissioning, training, preventative maintenance, spare parts and warranty support, and remote diagnostics to support reliable long-term operation.