Addressing next generation solar inverter designs

UNTERHACHING, GERMANY: As the solar market matures, electronic power designers are faced with new challenges in inverter designs.

The older, less efficient two level designs will simply not meet next generation requirements, nor compete successfully in the marketplace. Increasing the efficiency and using a higher switching frequency is becoming the norm.

To add to the complexity, customers are requesting a higher DC input voltage to the inverter.

Each of these factors must be carefully balanced to provide the best cost-to-performance ratio to meet tomorrow's challenge of next generation solar inverters, while keeping costs in check.

Vincotech, a leader in power module technology is addressing these needs designing revolutionary topologies while using best-in-class dies and packaging.

Many customers are looking at ways to reduce overall systems cost, not only in the inverter, but the number of panels and connections used. By increasing the panel array voltage to the system, it lowers the total DC current while increasing the rated power for solar inverter. This can result in significantly lower costs for the DC infrastructure as well as the overall balance of system costs.

Since the power of the solar inverter system is limited mainly by the current, the power can be substantially increased by increasing the operating voltage, resulting in additional cost savings. This system configuration simplifies the inverter design since a DC boost is not required, lowering the cost to the inverter.

"All utilities are looking for 1000-V inverters," John Skibinski, VP Market Development, AETI, says. "People have been hesitant to build so large because the National Electric Code (NEC) doesn't mandate them to be that big. So why fight the NEC? Such inverters, however, are standard in Europe, and will eventually become standard in the United States."

Alan Beale, director of sales-and-marketing for San Jose-based REFUsol USA, says there are even companies that are putting 1500 V inverter pilot projects in the ground. "There are a handful of companies doing 1500 V inverters and 1500 V panels. In another two years, that's where the entire industry will be."