As the automotive market demands improved driving range in electric vehicles (EVs), highly efficient power electronics solutions are a focal point for researchers. Specifically, the low-voltage high-current nature of auxiliary power modules (APMs) with power ratings in the kilowatt range pose a challenge in hindering overall driving range of EVs. Three-port converters (TPCs) enable a highly efficient and power dense means of integrating the DC-DC portion of the on-board charger with the APM in a consolidated solution. To minimize the volume of the three-winding transformer, integrating the TPC, a two-stage APM is assumed in this article in which the second-stage consists of a synchronous buck converter (SBC) capable of 48 V to 9–16 V at 3.6 kW. With a maximum current of 250 A, phase interleaving of the SBC is necessary to improve overall power conversion efficiency. To ensure a sufficient balance of total volume and power loss, a design optimization framework for the SBC is presented in this article. Considerations of parameter variation, device and passive losses, and choice of non-coupled versus coupled inductors are the basis of the developed analytical models used in loss evaluation and inductor design. Results of the framework for 2060 unique designs are presented wherein trade-offs for three optimal designs are discussed yielding the final hardware demonstrator. Experimental results for power conversion efficiency are compared to the analytical model yielding a root mean square error of ~0.24% over the converter operating range.

Employment of Silicon Carbide (SiC) devices and the use of multiphase drives are two emerging trends in electric vehicle (EV) applications. However, technology assessment combining both trends for traction applications has not been thoroughly examined yet. This paper presents a quantitative and qualitative analysis to examine the feasibility of SiC-based multiphase traction inverters. Specifically, voltage source inverters (VSI) and nine switch inverters (NSI) with different phases (five-, six-, and nine-phase) are evaluated in terms of device count, dc-capacitor sizing, efficiency, power density, and cost. The multiphase inverters in the case study are rated at 100 kW considering 400 V and 800 V EV powertrains. Compared to the conventional three-phase VSI, the six-phase VSI was found to have the best feasibility. The latter enjoys reduced dc-capacitor requirements, lower ac cabling cost, and higher fault tolerance capability, while maintaining the same efficiency and power device count.

This paper presents an efficiency evaluation of two six-phase inverter topologies for automotive applications: voltage source inverter (VSI) and nine-switch inverter (NSI). Their efficiency is studied for electric powertrains rated at 400 V and 800 V, and using silicon carbide (SiC) MOSFETs rated at 650 V and 1200 V operating at a switching frequency of 30 kHz. Prior to efficiency evaluation, a thorough analysis on the total device count required for 100 kW design is investigated for both topologies. It is found that NSI enjoys a superior efficiency when compared to six-phase VSI, at the expense of increased total device count.

In this paper, a virtual-flux finite control set model predictive control (MPC) strategy for dual three-phase interior permanent magnet synchronous motors (DTP-IPMSM) is proposed. The technique is based on the conventional predictive current control, but it maps the measured variables into a virtual- flux domain, thus simplifying the prediction stage. The technique uses a flux-based cost function to track the estimated reference flux. The flux tracking cancels out to guarantee an improved current tracking, and thus, a better torque ripple. The proposed technique is validated through simulation of a 100 kW DTP- IPMSM in Matlab/Simulink. Results evidenced a reduced current control error, thus improving the torque tracking up to 38.9 % when compared to the conventional inductance based model predictive control.

This paper proposes an adaptive voltage regulation (VR) flux-weakening (FW) control technique for dual three-phase (DTP) permanent magnet synchronous machine (PMSM) drives. Firstly, a small-signal model is developed to demonstrate the need of gain adaptation in order to maintain the controller bandwidth. Moreover, the small-signal model serves as a tuning tool for the FW proportional-integral (PI) controller. Then, the proposed adaptive controller is implemented and tested on a 100 kW DTP-PMSM drive. Simulation results demonstrate an improved drive performance at high speeds when benchmarked against non-adaptive controllers. Furthermore, the adaptive controller offers an extended speed range.

Switched reluctance motor (SRM) has various advantages which makes it an excellent candidate for many applications; nevertheless, its main drawback is torque ripples. This paper aims to enhance the SRM operation by reducing its torque ripples without the need for expensive and sophisticated physical changes in the motor materials or design. The SRM converter firing angles are optimized to produce the lowest possible torque ripples. The response surface method (RSM) is used to obtain the SRM optimization function that relates torque ripples with firing angles, and grey wolf optimizer (GWO) is used to minimize this function. The objective function convergence speed using the proposed GWO is compared with genetic algorithm (GA), and it is found to be faster than GA. Simulation and experimental results show the effectiveness of the proposed approach in enhancing SRM operation by providing the SRM converter firing angles that result the minimum feasible torque ripples.

Recently, the control problem of a quadrotor unmanned aerial vehicle (UAV) has been undergoing massive research. In this paper, a nonlinear disturbance observer-based (NDO) controller is proposed for attitude and altitude control of a quadrotor, in order to estimate and compensate disturbances that are imposed naturally on the quadrotor due to aerodynamics and parameter uncertainties. It is demonstrated herein that the proposed observer can estimate external disturbances asymptotically. Subsequently, it is employed with an input-output feedback linearization (FBL) controller - rendered as a baseline controller - to achieve a composite controller capable of rejecting external disturbances rigorously. The resulting controller is compared with a FBL controller that is equipped with an integral component. Simulation results demonstrate a superior performance using the former controller for disturbance rejection.

Voltage source converter (VSC) plays a major role in the AC/DC interconnection. Its control stands as a significant issue as it determines the stability and performance of the system. Therefore, utilization of a control algorithm that can robustly reject disturbances is highly appreciated. This paper proposes a new approach for PI-parameters selection, used in the decoupled dq-vector control scheme, based on first-order-plus-time-delay (FOPTD) models, for which analytical formulas for optimal controller design/tuning can be obtained. Furthermore, a non-linear optimization algorithm is developed in order to achieve the optimum disturbance rejection in terms of minimizing the integral time absolute of the error (ITAE) performance index. The cost function employs a weighted-sum criterion for two sources of disturbances, namely AC input voltage fluctuation and load disturbances, which may affect the regulated voltage. Simulation results demonstrate a very similar system performance using the FOPTD tuning parameters compared to the optimum ones where both yield a robust system against disturbances. The obtained results are also verified experimentally.