Electric Vehicles

Recent research in this area is directed at substantially reducing the loss of drivetrain power electronics over standard EPA drive cycles. These gains are achieved through a new听composite converter听approach, with demonstrated reduction in average loss by a factor of 2-4. Earlier research includes power conversion for on-board chargers and for facilitation of a 42 VDC standard.

Composite Converter Architectures: Beyond Multilevel Modular Conversion

Distribution (PDF) of electric vehicle DC bus voltage and power for a simulated US06 (aggressive) drive cycle, where there is an upwards trend of normalized IP as V increases.

Distribution (PDF) of electric vehicle DC bus voltage and power for a simulated US06 (aggressive) drive cycle.

Electric vehicles operate most of the time at 10% to 20% of their rated power. Typically, converter efficiency is relatively low at these operating points. There is an opportunity to substantially reduce the loss of the drive train power electronics over typical drive cycles, thereby reducing temperature rise, cooling system load and improving MPGe.
  1. H. Chen, K. Sabi, H. Kim, T. Harada, R. Erickson, and D. Maksimovic,听听IEEE Energy Conversion Congress and Exposition, Sept. 2014.
  2. H. Chen, K. Sabi, H. Kim, T. Harada, R. Erickson, and D. Maksimovic,听IEEE Transactions on Power Electronics, vol. 31, no. 1, pp. 101-110, Jan. 2016.
    Conference paper [1] and updated journal paper [2] describe a new composite converter approach and its application to electric vehicle drivetrains.
  3. H. Kim, H. Chen, D. Maksimovic, and R. Erickson,听听IEEE Energy Conversion Congress and Exposition,听Sept. 2015.
    This paper documents design and experimental results of a 30 kW boost composite converter for an electric drivetrain application.

  4. Graph comparing efficiency vs. power for conventional boost vs. composite converter, where the efficiency of a composite converter increases exponentially starting at 3 kW and levels around 97%, and a conventional boost begins to exponentially increase at 0 kW and maximizes at 98% efficiency.

    Comparison of efficiency vs. power for conventional boost (solid line) vs. composite (experimental data points), 250 V : 650 V, 30 kW rated converters. It is remarkable that 98% efficiency is maintained down to nearly zero power.

    H. Chen, H. Kim, R. Erickson, and D. Maksimovic,听听IEEE Transactions on Power Electronics听Jan. 2017.
    Options for performing the boost function in EV drivetrains are compared using a calibrated loss model, to predict total loss over standard EPA drive cycles, as well as size of the reactive elements. The composite converter approach reduces the loss over typical drive cycles by a factor of approximately four, while also reducing the size of the system film capacitors.
  5. U. Anwar, H. Jin, H. Chen, R. Erickson, D. Maksimovic, and K. Afridi,听听IEEE Energy Conversion Congress and Exposition, Sept. 2016.
  6. H. Kim, H. Chen, D. Maksimovic, and R. Erickson,听听IEEE Energy Conversion Conference and Exposition, Sept. 2016.
  7. H. Kim, H. Chen, Z. Cole, B. Passmore, K. Olejniczak, R. Erickson, and D. Maksimovic,听听IEEE Applied Power Electronics Conference, Mar 2017.
  8. H. Kim, H. Chen, J. Zhu, D. Maksimovic, and R. Erickson,听听IEEE Workshop on Wide Bandgap Power Devices and Applications, Nov. 2016.

Earlier Work Related to Vehicle Power Electronics

  1. J. Hong, D. Maksimovic, R.W. Erickson, and I. Khan, 鈥淗alf-Cycle Control of the Parallel Resonant Converter Operated as a High Power Factor Rectifier鈥,听IEEE Transactions on Power Electronics,听vol. 10, no. 1, pp. 1-8, January 1995.

  2. Stephen W. Anderson, Robert W. Erickson, and Ronald A. Martin, 鈥淎n Improved Automotive Power Distribution System Using Nonlinear Resonant Switch Converters,鈥澨IEEE Transactions on Power Electronics,听January 1991.

  3. Stephen W. Anderson, Robert W. Erickson, and Ronald A. Martin, 鈥淎n Improved Automotive Power Distribution System Using Nonlinear Resonant Switch Converters,鈥澨IEEE/SAE Workshop on Automotive Power Electronics,听August 1989.
  4. Robert Erickson, Adan Hernandez, Arthur Witulski, and Renjie Xu,听听IEEE Power Electronics Specialists Conference,听1989 Record, pp. 43-50, June 1989. Also in听IEEE Transactions on Power Electronics, vol. 4 no. 2, April 1989, pp. 242-252.