Ideal Power released a white paper describing a new power semiconductor switch called the Bi-directional Bipolar Junction TRANsistor (B-TRAN) and its method of operation as well as the implications of the B-TRAN as a replacement for conventional power switches. The technical whitepaper describing the device structure and operation of the B-TRAN is available at B-TRAN White Paper.

Ideal Power was granted five U.S. patents, patent numbers 9,029,909; 9,035,350; 9,054,707; 9,054,706 and 9,059,710, for the B-TRAN device and its methods of operation. Additional U.S. and international patents are pending.

The B-TRAN device has a simple, 3 layer, 4 terminal, vertically-symmetric double sided structure which presents unique opportunities for high current density operation at high efficiency. B-TRANs have potential uses in a wide range of power conversion and control applications, including low-loss AC power control, and power converters. Based on a recent study by Yole Development, power semiconductor switches are a $10 billion per year addressable market currently served by conventional devices such as Insulated Gate Bipolar Transistors (IGBTs).

“Given the performance predictions for this new power switch topology, the B-TRAN may be the most significant new type of power semiconductor since the introduction of the IGBT,” says Dr. Richard Blanchard, a B-TRAN co-inventor and holder of over 200 patents primarily related to power semiconductors, including the widely-used MOSFET.

“These B-TRAN patents, along with other pending Ideal Power patents covering methods of double sided power switch manufacturing and operation, extend our intellectual property portfolio into power semiconductors, which we believe could significantly improve power conversion efficiency in a wide range of applications. These include AC power control, Ideal Power’s Power Packet Switching Architecture (PPSA) topology, conventional power converters and non-conventional power converters,” stated Bill Alexander, Chief Technology Officer, founder of Ideal Power and a B-TRAN co-inventor. “High-efficiency power converters deliver more power for the customer, resulting in potentially lower cost, and more reliable and smaller products.”

Ideal Power’s current products using standard IGBTs deliver some of the highest efficiencies for energy storage applications. The company believes that future Ideal Power products using B-TRANs could have full power conversion efficiencies equal to or exceeding 99%, as compared with conventional power conversion systems with typical full power efficiencies of less than 95%. Third party simulations show that, when applied to AC power control, the B-TRAN is predicted to operate with less than 20% of the conduction losses of conventional solid state AC power control devices while providing valuable fault control capabilities such as current limiting and fast turn-off during fault conditions, which are lacking in such conventional devices. The B-TRAN could also potentially replace electro-mechanical contactors in many applications where fault limiting and explosion-proof operation is required.

The development of the B-TRAN has been supported by a U.S. Department of Energy Advanced Research Projects Agency – Energy (ARPA-E) award to create new bi-directional IGBT (BD-IGBT) power switches. Unlike conventional uni-directional power switches, bi-directional switches conduct current and block voltage in both directions.  As part of this advanced research, the company patented the B-TRAN, which combines the bi-directional functionality of the BD-IGBT with exceptionally low losses.

Both the BD-IGBT and the B-TRAN have been extensively studied in detailed, physics-based simulations, and the semiconductor processes to build prototype devices are in development. These simulations show a 0.2 V drop on a 1200 V B-TRAN at high current density and gain greater than 10, as compared to a typical IGBT with series diode voltage drop of 4.5 V, for a factor of 22 reduction in conduction losses in IGBT AC switch applications. B-TRAN switching losses are predicted by these simulations to be significantly lower than IGBTs.