Renewable Energy Power Converters

Umbrella Technologies is pioneering a new wave of true high efficiency power converters geared to the alternative energy markets. Current converters’ efficiencies have been nominally improved in recent years, e.g. by eliminating transformers as design elements. Under static test conditions, converters’ efficiencies (“η”) have improved to as much as 98%. However, this static measurement of η is an idealized one, which ignores inefficiencies in the real world.
In its simplest form, measurement of η involves measuring DC power in and AC power out at a selected voltage. Some attempts have been made to improve the measurement of η by incorporating operation of the converters at a variety of input voltages to reflect the less than optimal “real world” conditions. Even this “η total” calculation is based upon the assumption of an idealized AC load measurement, i.e. a root mean square, resistive AC load. Thus the concept of inductive load phase shifts and total harmonic distortion (“THD”) does not even enter into the calculation of η. Thus, seeing converters’ data sheets quote 98% efficiency and whopping <5.0% THD is not unusual. Umbrella’s designs will accomplish the same stated efficiencies, while dropping the THD to under 0.1%: a 50X improvement.
Another hidden inefficiency is lost power due to less than ideal power factors. In the real world, converters encounter inductive loads, such as from motors, electronic ballast lighting and HVAC compressors. These inductive loads cause a phase shift, wherein the difference between real and apparent power may be on the order of 25 to 40%, directly representing lost power and generating capacity. The current utility grid system is dominated by central station power generation. Thus, the grid overwhelms the effect of any phase shifts caused by inductive loads and pushes the inefficiencies to the inverter site. In a distributed generating world where renewable energy may represent 20 to 25% of the electric generation, these phase shifts and differential can become a power quality issue at the grid level.
This becomes a critical requirement for converters as distributed generation via renewable energy resources becomes a greater portion of the electrical generating capacity. Converters are not designed to load balance their wave forms in reaction to inductive loads, e.g. motors. Thus, converters’ efficiencies can decline by as much as 25 to 40% when coupled to an inductive load.
Principal Design Characteristics
  • Real-time, adaptive operation
  • Modular design
  • Medium and high power applications addressed
  • Transient power protection
  • Maximum power protection
  • Minimum power protection
  • Smart feedback
Power Options
1kw – 3kw – 10kw