In this paper, we aim to investigate the path following control problem for four-wheel-independent-drive electric vehicles (4WID-EVs) with consideration of modeling error and complex driving scenario. In order to guarantee operational safety and performance of robustness, a super-twisting secondorder sliding mode (SOSM) control strategy is employed to suppress the heavy chattering problem existing in the traditional sliding mode control (SMC). To degrade the lumped disturbance, a nonlinear disturbance observer (NDOB) technique is proposed to estimate the disturbance and compensate the modeling error. Then, a composite control strategy which combines the SMC algorithm and NDOB is proposed base on stability analysis of the corresponding closed-loop system. Finally, simulation results and comparisons show that the super-twisting SOSM control algorithm with the NDOB technique can achieve better tracking performance and suppress the chattering.

Power module packaging technologies are undergoing extensive changes to satisfy compact high-power-density systems. The advantages of double-sided cooling power module in thermal and electrical compared to wire-bonding are summarized. Some typical double-sided cooling power modules developed by institutes or companies are introduced in detail. The challenges and future trends of double-sided cooling power modules are also highlighted.

It is challenging to package SiC power devices for high-voltage applications. Field-dependent conductivity (FDC) materials, which has nonlinear electric conductivity and were proved capable of reducing peak electric field intensity greatly at the triple points, had attracted much attention. However, it was more critical to make the FDC insulation reliable against high temperature and thermo-mechanical shocking. In this paper, we proposed a new polyimide-based FDC coating (PI-FDC-C), which was capable of improving the equivalent heat resistance temperature by almost 100°C and reducing the thermo-mechanical stresses greatly by 45.1%, as a robust insulation for packaging high-voltage power devices. The partial discharge inception voltage (PDIV) of module demonstration could be improved by at least 55%. There was no degradation of nonlinear electric conductivity after 120 hours storage at 200°C and no crack or interfacial delamination in the adjacent of the triple points even after 1000 cycles of the thermal shocking. It is quite encouraging to use the PI-FDC-C as a robust alternative to packaging high-voltage SiC power devices.

For electrified transportation (eTransportation) systems, multi-phase motors can provide higher performance and reliability than three-phase ones, but also bring more challenges in their optimal design and control. In this article, a set of high reliable electric drive system based on dual three-phase permanent magnet synchronous motor (DTP PMSM) is developed for auxiliary systems in eTransportation field. A digital collaborative develop process is proposed with the support of multiple software tools. Design, manufacture, and bench testing stages of the DTP PMSM, the two-level six-phase inverter, and the control algorithm are efficiently incorporated. A prototype of the multi-phase electric drive system is fabricated and tested. Comparison of the simulation analysis and experimental results confirms the effectiveness of the collaborative develop progress. Control algorithms based on dual d-q model and vector space decomposition model are both verified and compared via the bench test. Operation mode switching from six-phase mode to three-phase mode is also realized with the prototype system, verifying its capability in fault-tolerant and potential in efficiency optimizing.