Power electronic energy conversion is becoming commonplace in a multitude of applications including hybrid electric vehicles, military aircraft, unmanned aerial vehicles, ship power systems, and alternative energy sources (wind, solar, tidal, wave). At Mainstream, we are developing the power electronics and control algorithms that run these systems, which range in power from 100s of watts (battery chargers and low-power supplies) to over 100 kilowatts (pulse-power supplies, permanent-magnet motor drives, and point-of-use converters). These new power electronic systems are increasing the achievable power densities, increasing system efficiencies, and enabling installation into a growing field of applications.
Research Areas
In addition to our internally funded research, we perform sponsored research for government and industry clients. Our research sponsors include the Army, Navy, Air Force, Marines, NASA, Department of Energy (DOE), Department of Transportation (DOT), and others.
Our power electronics and controls R&D is focused in four areas:
Characterization of Advanced Wide-Bandgap Semiconductors
- SiC devices used in several of our high-speed motor drives and high power density supplies
- GaN die characterization over wide-temperature ranges (-225 °C to 150 °C) – the switching loss testing is shown on the left
- GaN devices used in high ambient temperature (71 °C)-based dc-dc converter for high-current (500 A) low-voltage 28 V systems
- Custom gate drive electronics for superior performance in GaN-based power converters
High-Speed Motor Drives and Control Algorithms
- 2 kW bi-directional PM motor drives for ISA/hybrid vehicle and portable generator applications (shown on left)
- Ram-air-turbine electronics interface and control
- 15 kW and >98% efficient SiC-based variable-frequency drive for ultra-high-speed (>100 kRPM) PM motor/generators (100 °C liquid-cooled version shown below)
Lightweight, Low-Volume Power Supplies
- 60 Hz to 400 Hz solid-state frequency conversion
- Pulse power supplies with hybrid energy storage
- High-efficiency integrated fuel cell electronics
- Portable battery chargers (shown below)
Alternative Energy and Utility Grid Interface
- High-efficiency wind/solar electronics and control
- Thermoelectric generator grid interface
- Active filtering for grid interface applications
- Smart coordination and control of hybrid micro-grids
Our Approach
At Mainstream, we focus on both the analytical design as well as experimental based development. Rather than rely solely on analytical or numerical modeling, our power electronics engineers focus on building hardware early in the design phase to flush out problems and expose new research opportunities. We start by getting a clear understanding of a customer’s needs, optimize the specific system around those set of requirements, and then build a prototype system to demonstrate feasibility.
We use small, multi-disciplinary design teams to address the unique problems associated with high-performance power electronics and controls. This approach fosters creativity among team members and results in novel solutions to problems. To speed development timelines, we use computer simulation programs and rapid-prototyping tools extensively.
Unlike most other small companies, Mainstream is engaged in all aspects of providing solutions from initial concept through final manufacturing, sales, and support. We encourage you to see for yourself at our Patents, Manufacturing, and Products pages.
Our Labs and Capabilities
Mainstream has a diverse set of capabilities for testing and developing power electronics, motor drives and general control solutions including the following:
- Low-power test lab for battery chargers and other low-power power supplies
- Micro-grid for grid interface testing and alternative energy technology insertion
- Design and testing of motor drive and ISA power electronics
- High-power lab for pulse power and 270 Vdc bus interface testing
