This design is a digitally-controlled, grid-tied, solar micro inverter with maximum power point tracking (MPPT). Solar micro inverters are an emerging segment of the solar power industry. Rather than linking every solar panel in an installation to a central inverter, solar micro inverter-based installations link smaller, or “micro,” inverters individually to each solar panel. This configuration lends itself to many benefits, including elimination of partial shading conditions, increased system efficiency, improved reliability and greater modularity. For this design, a C2000™ Piccolo™ TMS320F28035 microcontroller (MCU) is the digital controller for the complete inverter, including control of the power stages, MPPT, and grid-tie synchronization. The power conversion stages include 1) an active clamp fly-back DC/DC converter with secondary voltage multiplier and 2) a grid-tied, DC/AC inverter. The design achieves 93 percent peak efficiency and less than 4 percent total harmonic distortion, providing more power output per solar panel, reducing detrimental heat dissipation, and increasing system longevity.
Features
- Implements control of an active clamp fly-back DC/DC converter with secondary voltage multiplier, MPPT and a grid-tied DC/AC inverter, comprising the power conversion stages of the solar micro inverter
- Supports panel voltages of 28 to 45V at input as well as universal power output at up to 280W for 220VAC and up to 140W for 110VAC, making it suitable for the diverse requirements of worldwide solar markets
- 93 percent peak efficiency and less than four percent total harmonic distortion (THD) provide more power output per solar panel, reducing detrimental heat dissipation and increasing system longevity
- C2000 Piccolo F28035 MCU serves as a high-performance controller for the complete micro inverter system, executing high-frequency control loops for the DC/DC and DC/AC power stages
- Single-MCU system implementation offers design simplicity and reduced system cost
- C2000 Piccolo F28035 MCU operates the inverter at a high PWM frequency (100 KHz) to reduce harmonic distortion and lower passive component costs
- Solar and digital power software libraries provide code-optimized building blocks to implement a variety of power topologies and algorithms such as MPPT and Software Phase Locked Loops (PLL), perfect for designing customized solar inverter solutions
- Fully-functional evaluation board includes software, hardware design files, quick start graphical interface and step-by-step documentation
NOTE: Software for this board is located inside the controlSUITE™ software package. Download controlSUITE at ti.com/controlsuite. Once installed, navigate to "Solar Micro Inverter Development Kit" under the Development Tools -> Solar section.