Grid-Tied Solar Micro Inverter Reference Design

Designed for various industrial applications—including central inverters, single-phase string inverters, and modular micro inverters—this grid-tied solar micro-inverter solution provides a robust, adaptable platform for advancing solar energy systems worldwide.

This reference design introduces a digitally-controlled, grid-tied solar micro inverter with maximum power point tracking (MPPT), tailored for modern solar power applications. Solar micro inverters mark a significant innovation in the solar industry by offering an alternative to traditional systems that connect all solar panels to a central inverter. Instead, each solar panel connects to its micro inverter, resulting in several advantages, such as eliminating partial shading issues, enhanced efficiency, improved reliability, and modular scalability.

This design TIDM-SOLARUINV by Texas Instruments is the C2000 Piccolo TMS320F28035 microcontroller (MCU), which functions as the digital controller for the entire inverter system, including control of power stages, MPPT, and synchronization with the grid. The power conversion process relies on two key stages: an active clamp fly-back DC/DC converter with a secondary voltage multiplier and a grid-tied DC/AC inverter. This system achieves a peak efficiency of 93% and maintains less than 4% total harmonic distortion (THD), maximizing power output, reducing heat dissipation, and extending system longevity.

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This design offers flexible support for panel input voltages ranging from 28V to 45V, and it delivers universal power outputs—up to 280W for 220VAC systems and up to 140W for 110VAC systems—ensuring compatibility with diverse global solar market requirements. The high-frequency operation of the inverter at 100 kHz minimizes harmonic distortion and reduces the cost of passive components, enhancing overall system efficiency and affordability.

The single-MCU architecture, driven by the C2000 Piccolo F28035, simplifies system design, reduces cost, and enables precise high-frequency control loops for both DC/DC and DC/AC power stages. Pre-designed software libraries further enhance customization, offering optimized building blocks for power topologies and algorithms like MPPT and software phase-locked loops (PLL). The design package includes a fully-functional evaluation board complete with hardware design files, pre-loaded software, a quick-start graphical interface, and detailed documentation for streamlined implementation. This comprehensive approach supports the development of efficient, reliable, and customizable solar solutions.

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TI has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.