Power Electronics

Power electronics is the segment of electronics whose purpose is to convert or condition electrical power from one form (that which is available) to another form (that which is needed) through the use of power semiconductors and other more traditional types of electrical components. Power electronics products and systems are found throughout the generation, distribution and use of electrical power.

The combined worldwide market for power electronics products exceeds $70 billion annually. Important segments of the market include the following:

  • Variable frequency motor drives for automation ($12 billion)
  • Power supplies for instruments and computers ($16 billion)
  • Uninterruptible power supplies, active filters and other power quality products ($10 billion)
  • Propulsion systems for electric and hybrid vehicles
  • Converters for renewable and alternative power, such as wind turbines, hydro turbines, generator sets, photovoltaic cells, fuel cells and microturbines ($4 billion)
  • Power conditioners for energy storage systems, such as flywheels, super capacitors and batteries
  • Welders
  • Industrial power supplies for metal heating and plating

While power electronics products cover a broad power range from watts to hundreds of megawatts, Peregrine is interested primarily in medium power applications, that is, applications between one kilowatt and one megawatt. However, Peregrine has worked on projects involving power levels above and below this range.

Many sophisticated technologies contribute to the success of power electronics products and systems. The following chart shows some of these.

Power Electronics Landscape




High Performance Magnetics

In developing advanced power electronics, Peregrine has needed high performance inductors and transformers that were not available in the market. The requirements imposed on these components included the following:

High power - tens of kW and higher
High current - hundreds of amps and higher
High frequency - tens of kHz and higher
High efficiency - 99% and higher
Tailored leakage inductance
High temperature capability - over 175C
Cores made of nano-crystalline material
Small size

Peregrine has developed internal skills and proprietary technologies, along with important relationships with specialized vendors, for designing and fabricating such magnetic components. Since most companies, including major defense contractors, consider this activity to be specialized and sporadic, they have not generally staffed for it. Therefore, Peregrine has added a new line of business in which its team will assist them in designing and fabricating high performance magnetics.






Past Projects

The staff and associates of Peregrine have carried out dozens of engineering and R & D projects. A sampling of the products or prototypes developed is given below.

High power uninterruptible power supply with soft switching, sponsored by one of the largest suppliers of UPSs in the world - $2.7 million
Variable speed generator set, sponsored by the US Army and others - $2.8 million
Soft switching drive for an electric vehicle, sponsored by US Department of Transportation and a major auto company - $500,000
High power bi-directional converter for NASA's More Electric Aircraft Program, sponsored by a major supplier of generators for commercial aircraft - $650,000.
Industrial drive with soft switching, sponsored by one of the largest motor manufacturers in the world - $400,000.
Soft switching inverter for photovoltaic systems, sponsored by US Department of Energy - $100,000.
Advanced motor drive for agriculture pumping in California, sponsored by the California Energy Commission - $970,000.
Universal converter for use on ships which travel internationally to reconcile dockside power to that required onboard - internally funded.
Active filter for canceling harmonic distortion and correcting poor power factor, sponsored by venture capitalists - $7 million.

Back to TopRecent and Ongoing Projects

SiC-Based Converters for Wind Turbines



In this project, the Peregrine team determined the impact on the cost of energy (COE) generated by a large (1.5 MW) wind turbine from the use of SiC power semiconductors in the power converter that enables variable speed operation.

SiC devices have been under development for over 20 years because, as a wide band gap material, they offer many dramatic improvements. Compared to standard power semiconductors, such as the popular silicon IGBT, SiC devices have lower losses, higher switching frequencies, higher operating temperature, higher voltage and higher thermal conductivity.

In this project, Peregrine characterizated SiC power semiconductors to be used in a variable speed wind turbine, and evaluated the readiness of SiC technology for this application. The team concluded that COE would be improved substantially, particularly if a medium voltage converter were used.

This project was sponsored by the US Department of Energy, acting through the National Renewable Energy Laboratory (NREL).

Dispatchable Distributed Energy Storage for the Smart Grid

        

Peregrine has a project funded by the Department of Energy for the installation of small energy storage systems at the sites of residential and small business customers of the utility. The storage medium will be either a fixed battery bank or the batteries in an electric vehicle. The goal is to make thousands of small storage units act like utility scale units by linking their controls to the utility operations center using new solid state meters and the associated advanced metering infrastructure (AMI). The primary purposes for the storage will be to support the utility by (1) shifting power generation to match loads, (2) peak shaving, and (3) providing support for frequency regulation and short-term load balancing. Peregrine is working closely with its local electrical utility, who has installed over 800,000 of the new meters. Success in this project will encourage the use of renewable energy from wind and PV systems. The Pacific Northwest region where Peregrine is located now has nearly 4,000 MW of intermittent wind power and is expected to have up to 14,000 MW in the years ahead. This creates serious issues when integrated into a grid with traditional on-demand generation systems. Energy storage will give utilities an important tool for mitigating these issues.

10 kW Tactical Inverter for Army Mobile Power



Peregrine has developed a prototype 10 kW Tactical Inverter for mobile power applications. This unit draws power from military 28VDC sources, such as batteries and fuel cells, and produces three-phase 120/208 AC power. It uses SiC power semiconductors to achieve small size and high efficiency, and a high frequency transformer to provide galvanic isolation.

This project was funded by the Army and Navy (on behalf of the Marines).

Ultra-Light 1 kW Genset

                               

Here, Peregrine developed a preliminary design for a 1 kW one-man portable genset using a small, high speed JP8 reciprocating engine designed for unmanned air vehicles (UAVs). A unique engine developed in prior work funded by DARPA was adapted to the application, fabricated and operated. The Peregrine team concluded that such a genset was feasible and it would weigh between 16 and 19 pounds, depending upon its configuration. The primary application for the genset would be the charging of batteries by groups of 10 to 100 soldiers.

This work was supported by Army mobile power.

Power Supply for Radar Decoy for Military Aircraft

                

Peregrine is currently working with the Navy on the next generation aircraft radar decoy. Peregrine's contribution is a unique, extraordinarily small, efficient power supply.

SiC-Based Converters for Army Mobile Power



Power electronics converters can improve the mobility of generator sets using reciprocating engines by permitting them to operate with variable speed. By decoupling them from the load with a converter, the engine can be operated at higher speeds, giving higher power output. They can also run at less than full speed when providing less than full power, giving significantly higher fuel efficiency. Both of these factors can be exploited to reduce size and increase mobility. In addition, the converter can produce many forms of power, enabling a single genset to supply power to a wide variety of loads and reducing the genset inventory significantly.

In this project, Peregrine developed an advanced converter for a 3 KW genset using SiC power semiconductors. It is much smaller than existing converters that use standard silicon power semiconductors. It may be the most efficient inverter ever built for the given conditions. The converter can also be used in many other energy systems such as those with fuel cells and photovoltaic cells.

The project was sponsored by the U.S. Army.

Back to TopSiC-Based Converters for Distributed Power



Peregrine carried out a contract to develop a SiC-based converter rated at over one MW for use in alternative power generation systems, such as those using utility-scale wind turbines, fuel cells and photovoltaic cells. By exploiting the higher efficiency, higher voltage and higher temperature capability of SiC devices, the converter is expected to be much smaller and eventually less expensive than a converter using standard silicon devices.

This project was funded by the U.S. Department of Energy acting through Sandia National Laboratory.

Wave Power Generation Systems



The generation of power by harnessing the energy in ocean waves is only at the beginning of its development. It has many of the advantages of wind generation, including low impact on the environment and the absence of the combustion of fossil fuel. About two-thirds of the world's population lives within 200 miles of a coast line.

Peregrine was awarded a contract by U.S. Department of Energy to develop and evaluate specific wave power systems. The project was carried out in collaboration with Oregon State University (OSU), which has an active, ongoing program for the development of wave generation systems. Peregrine and OSU focused primarily on a generating buoy that converts the heaving motion of waves into electrical power.

OSU is ideally situated to develop wave power systems since it has a nationally recognized power lab and a wave test facility used frequently by the Army Corps of Engineers and the Navy, plus several seaworthy work vessels. The Oregon coast has one of the best wave power resources in North America. Leadership in wave energy research at OSU is provided by Dr. Annette von Jouanne and Dr. Ted Brekken.

Bi-Directional Converter for Navy Ships



Navy ships of the future will rely much more heavily on electrical power (advanced motors and power electronics), rather than steam, hydraulics and mechanical systems. This high frequency, bi-directional converter will enable the rapid reconfiguration of the sources, loads and storage systems on-board a ship in the event of damage. It relies on SiC devices and nano-crystalline magnetics material to achieve high efficiency and small size.

This project is funded by the Office of Naval Research.

Back to TopVariable Speed Helicopter Rotor



To date, continuously variable speed rotor systems have not been successfully implemented in helicopters. NASA funded the evaluation by Peregrine of a unique, patented system that achieves small size and weight by blending advanced mechanisms, motors and SiC-based power electronics.