Cleanfield Energy™ has developed a 60kW Universal Inverter (UI). The UI has received positive test results to date at the Atlantic Wind Test Site in Prince Edward Island. It was installed at the Wind Energy Institute of Canada (WEICan) in May 2006 and is undergoing testing and evaluation.

The Universal Inverter allows for the development of an inverter product family for wind turbine applications ranging from 30kW to 250kW. The UI can work on a variety of generators, such as induction, synchronous with permanent magnets or field windings, and DC. The UI works with generators with the nominal stator frequency at 50 Hz or 60 Hz and with low-speed direct shaft generators. The UI can deliver the energy produced to a three-phase or single-phase grid or can work in an autonomous system and create its own three-phase or single-phase grid. In all situations, the grid frequency can be 50 Hz or 60 Hz. This variety of applications involves reconfiguration of building blocks and loading of different firmware.

The hardware uses a classical approach of two power converters, one controlling the generator to turn the turbine to an optimal speed (maximum output power) and the second to transfer the energy produced by the generator to the AC line. In situations in which there is a significant difference between the generator’s voltage and the AC voltage, the cost of the application will dictate the use of a transformer between the AC line and the UI or a DC boost or buck-cell between the two power converters.

Using the UI in a wind turbine application produces energy at lower wind speeds. Once the turbine turns, depending on its performances, the inverter can deliver energy to the grid.

The UI has been developed in accordance with international standards in terms of power quality, safety and environment.