Next Generation Power Converters for Distributed Wind Applications

Statement of the Problem There are presently no UL1741 certified, commercially available inverters or turbine ac-dc converters available for the US distributed wind market. “Distributed Wind” is defined as 10 kW to 1 MW in turbine rated power. Intergrid has been working to solve this problem for small wind turbines up to 25 kW rated power. Also new work under NREL Component Improvement contracts promises to bring certified 36 and 80 kW inverters to market. There remains a great need for inverters and turbine power converters for both lower and higher power ranges. For example, a 10 kW rated turbine is ideal for supporting residence-scale or critical infrastructure.How We Address the Problem 1/ Power stage development from 12.5kW to 150kW with a world-class supplier. 2/ Advanced controller design that enables higher switching frequencies and lower cost designs. 3/ Designing for UL1741, UL1998 and IEEE 1547 certification. 4/ Design for grid-connected, stand-alone and microgrid operation.Phase I Activities The focus in Phase I was: testing a 175 kW inverter power stage, the development of a new inverter controller capable of switching at 100 kHz, and the ability to certify a wide range of inverters to UL1741 and IEEE1547.Phase II Plans In Phase II, we will build on our Phase I work and develop: 1. Inverter power stage “families” ranging from 12.5 to 150 kW; 2. A controller based on the TI TMS320F28388D DSP chip; 3. Inverter control code certified to UL1998 (functional safety) and, 4. Control to support microgrid functions.Commercial Applications and Other Benefits The lack of certified inverters designed for wind and wind-hybrid distributed energy systems is a total impediment for the US distributed wind market.