Alexander B. Lostetter

A High-Density, High-Efficiency, Isolated On-Board Vehicle Battery Charger Utilizing Silicon Carbide Power Devices

This paper presents an isolated on-board vehicular battery charger that utilizes silicon carbide (SiC) power devices to achieve high density and high efficiency for application in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs). The proposed level 2 charger has a two-stage architecture where the first stage is a bridgeless boost ac-dc converter and the second stage is a phase-shifted full-bridge isolated dc-dc converter. The operation of both topologies is presented and the specific advantages gained through the use of SiC power devices are discussed. The design of power stage components, the packaging of the multichip power module, and the system-level packaging is presented with a primary focus on system density and a secondary focus on system efficiency. In this work, a hardware prototype is developed and a peak system efficiency of 95% is measured while operating both power stages with a switching frequency of 200 kHz. A maximum output power of 6.1 kW results in a volumetric power density of 5.0 kW/L and a gravimetric power density of 3.8 kW/kg when considering the volume and mass of the system including a case.

High-Temperature Silicon-on-Insulator Gate Driver for SiC-FET Power Modules

Silicon Carbide (SiC) power semiconductors have shown the capability of greatly outperforming Si-based power devices. Faster switching and smaller on-state losses coupled with higher voltage blocking and temperature capabilities make SiC an attractive semiconductor for high-performance, high-power-density power modules. However, the temperature capabilities and increased power density are fully realized only when the gate driver needed to control the SiC devices is placed next to them. This requires the gate driver to successfully operate under extreme conditions with reduced or no heat sinking requirements. In addition, since SiC devices are usually connected in a half- or full-bridge configuration, the gate driver should provide electrical isolation between the high- and low-voltage sections of the driver itself. This paper presents a 225°C operable, silicon-on-insulator (SOI) high-voltage isolated gate driver IC for SiC devices. The IC was designed and fabricated in a 1 μm, partially depleted, CMOS process. The presented gate driver consists of a primary and a secondary side which are electrically isolated by the use of a transformer. The gate driver IC has been tested at a switching frequency of 200 kHz at 225°C while exhibiting a dv/dt noise immunity of at least 45 kV/μs.

A Fully Integrated 300°C, 4 kW, 3-Phase, SiC Motor Drive Module

The researchers have designed, developed, packaged, and manufactured a complete multichip power module (MCPM) that integrates silicon carbide (SiC) power transistors with silicon on insulator (SOI) control electronics. The SiC MCPM approach targets the reduction of size and the increase in efficiency of power electronic systems resulting in a highly miniaturized, high power density module. The researchers previously presented a single phase 3 kW SiC inverter that was also proven operational to 250degC at 500 W. In this paper APEI, Inc. will present a new SiC three-phase inverter that has been fully tested to 4 kW at 300degC operation. In this paper, the researchers discuss the challenges associated with high-temperature operation of power electronics, including the electrical, mechanical, and thermal design. Many electronic packaging problems have been solved to enable high-temperature operation of these modules. These packaging issues will be discussed as well as remaining problems that still need advancing. Finally, the full temperature and full power (300degC at 4 kW) test results are presented.

A High-Temperature Multichip Power Module (MCPM) Inverter utilizing Silicon Carbide (SiC) and Silicon on Insulator (SOI) Electronics

The researchers at Arkansas Power Electronics International, Inc. have designed, developed, packaged, and manufactured the first complete multichip power module (MCPM) integrating SiC power transistors with silicon on insulator (SOI) control electronics. The MCPM is a 4 kW three-phase inverter that operates at temperatures in excess of 250 °C. Bare die HTMOS SOI control components have been integrated with bare die SiC power JFETs into a single compact module. The high-temperature operation of SiC switches allows for increased power density over silicon electronics by an order of magnitude, leading to highly miniaturized power converters. In this paper, the researchers will discuss the challenges associated with high-temperature operation of power electronics; present the electrical, mechanical, and thermal design of a high-temperature MCPM; discuss the multitude of packaging issues that were solved to reach high-temperature operation; illustrate the high power density and miniaturization achieved by the SiC MCPM; and present the experimental test results of the fully operational 4 kW SiC MCPM.

Ultra-lightweight, high efficiency SiC based power electronic converters for extreme environments

Silicon-carbide (SiC) semiconductor devices have numerous potential advantages over their conventional silicon counterparts (i.e., higher switching frequencies, lower switching losses, higher temperature of operation, higher blocking voltages, higher thermal conductivity, radiation hardness, etc.). These advantages have sparked the birth of a new generation of power converters, distinguishing themselves from their ancestors with a higher efficiency and operating frequency, resulting in a marked increase in power density and a considerable reduction in weight. This paper explores the feasibility of developing a highly efficient, ultra-lightweight SiC based DC/DC converter, including the electrical design philosophy, high-temperature packaging approaches, high-temperature testing of several key components, and the overall high-temperature package design. This technology will have important implications in many weight-sensitive applications such as aircrafts, satellite and NASA space exploration program. In addition, this technology will be highly beneficial for electronics that must operate in a high-temperature environment such as those located in the outside of spacecraft probes and landers

A Novel High Density 100kW Three-Phase Silicon Carbide (SIC) Multichip Power Module (MCPM) Inverter

The complete design strategy (mechanical and electrical) of a three-phase 100 kW power converter utilizing silicon carbide (SiC) and silicon-on-insulator (SOI) electronics is presented. The design philosophy focuses on size reduction through high temperature operation (200+ °C junction temperature). A low power, proof-of-concept prototype operating at 4 kW has been built and tested. The preliminary work renders the 100 kW module 75 % the size of comparable state-of-the art Si converters of the same voltage and power levels. The design approach makes use of the unique advantages of SiC devices while incorporating the necessary passive (capacitive and magnetic) technologies in order to complete a fully functional power module. High power density is obtained through high density integration of the control and power stages using multichip power module (MCPM) technology. The scaling of the low power module to the fully fledged three-phase 100 kW prototype SiC MCPM converter is analyzed in detail.

High-temperature silicon carbide (SiC) power switches in multichip power module (MCPM) applications

Arkansas Power Electronics International, Inc, (APEI, Inc.) and University of Arkansas researchers have developed a novel, highly miniaturized motor drive capable of operation in excess of 250 /spl deg/C. The high-temperature multichip power module (MCPM) integrates silicon carbide (SiC) JFET power transistors with high-temperature MOS silicon-on-insulator (SOI) control electronics into a single, highly miniaturized and compact power package. This paper will outline the design philosophy behind the high-temperature MCPM, illustrate thermal modeling results of the package, and present the results of prototype testing (demonstrating functionality).

Modeling vertical channel junction field effect devices in silicon carbide

The electrical characterization and model development for silicon carbide (SiC) vertical channel SIT and JFET structures are presented in this work. A compact model is developed based on the device geometry and SiC material properties. Northrop Grumman validates the model against measured data at 25 /spl deg/C and 100 /spl deg/C for a prototype 0.03 cm/sup 2/ SiC SIT provided. The models on-state and transient characteristics are validated over this temperature range. Validation of the model shows excellent agreement with measured data. The physics-based approach implemented in this model is crucial to describing the transient behavior over a wide range of application conditions and temperature ranges.

A UVLO Circuit in SiC Compatible With Power MOSFET Integration

The design and test of the first undervoltage lock-out circuit implemented in a low-voltage 4H silicon carbide process capable of single-chip integration with power MOSFETs is presented. The lock-out circuit, a block of the protection circuitry of a single-chip gate driver topology designed for use in a plug-in hybrid vehicle charger, was demonstrated to have rise/fall times compatible with a MOSFET switching speed of 250 kHz while operating over the targeted operating temperature range between 0°C and 200°C. Captured data show the circuit to be functional over a temperature range from -55°C to 300°C. The design of the circuit and test results is presented.

Solid-state fault current limiters: Silicon versus silicon carbide

As utilities face increasing fault currents in their systems as a result of increasing demand and/or deployment of new technologies, fault current limiters promise a solution that will mitigate the need for replacing existing breakers as well as being a general protective device for elements connected to the grid. This paper describes some recent advances in semiconductor-based fault current limiting technology including both the more mature silicon developments along with early developments using silicon carbide. The capabilities and limitations of these technologies are compared and contrasted. Some example scenarios of FCLs have been analyzed and are briefly described along with advanced features that semiconductor FCLs may bring to the solution space.