Integration of the electrical machine and drive system is an ongoing research topic among scholars in both academia and industry with the goal of increasing power density and efficiency to fulfill the requirements of aviation applications. The drive system structure and the modulation scheme impact the stator current ripple which affects torque ripple and efficiency. The case study of this paper is an integrated motor drive system of a 250 kW and 5,000 rpm direct drive surface permanent magnet machine. The imposed current ripple for different three- phase topologies (two-level VSI, and modular single-phase) using different modulation schemes (SVPWM for two-level VSI and Unipolar PWM for single-phase) are analytically studied. It is shown that in a modular single-phase full-bridge topology, the maximum peak to peak value of the current ripple is significantly lower than modular single-phase half-bridge and three-phase SVPWM modulated two-level VSI over the entire operating range. Furthermore, the torque ripple, stator core loss, and winding loss are evaluated for different current profiles through finite element analysis (FEA) simulations.

Multilevel Converter (MLC) design and control have been interesting topics in the last few decades. Due to the increased number of semiconductors in such topologies, the control problem becomes complex. Model Predictive Control (MPC) has been introduced in the 1980s and owing to significant advancements in processing power nowadays it is considered a viable option to control power converters. Fast dynamic response, simplicity, and the ability to include system nonlinearities and constraints in the cost function make MPC an interesting alternative for conventional linear controllers. In this paper, conventional Finite Control Set Model Predictive Control (FCS-MPC) has been improved by limiting the viable switching options based on the reference value. The performance of the proposed Model Predictive Nearest Level Control (MP-NLC) method is compared to the conventional FCS-MPC. The proposed method is applied to a 9-level inverter. To investigate the performance of the proposed MP-NLC method, simulations were carried out under linear and nonlinear loads. The presented results verify the fast dynamic response, and robustness of the proposed method. In addition, parameter mismatch analyses have been carried out on the proposed method as well. Based on the presented results, by using the proposed method total efficiency and specific power of the system are increased.

Photovoltaic (PV) systems are among the most convenient renewable energy sources (RESs) and are popular due to their easy implementation and low maintenance. Multi-input multilevel converters (MLCs) are suitable choices to harvest energy from PV systems and integrate solar farms into the existing power grid. In this paper, a new reconfigurable and multi-input converter is proposed for solar PV applications. It is also a practical solution for various medium to high voltage and power applications such as traction and HVDC. The symmetric and asymmetric configurations of the proposed MLC help achieve a higher number of output voltage levels and hence better-quality waveforms. The redundant output voltage vectors have improved the fault tolerance behavior of the proposed converter which enhances the reliability of the overall solar power system. Moreover, the proposed converter benefits from an improved model predictive control (MPC) technique which is customized for multilevel converters by adopting the nearest level control (NLC) algorithm. The proposed model predictive NLC (MP-NLC) method leads to high quality output voltage waveform (1.23% THD) under various load conditions while realizing an average switching frequency of lower than 6.8 kHz. A nominal load efficiency of 98.3% is recorded for the proposed MLC. The simulation results using Plexim PLECS software validate the functionality of the proposed converter and control method.

In this paper, the systematic design procedure of the proposed lead-lag direct power model predictive controller (L2DP-MPC) for active-front-end (AFE) rectifier is presented. First, the parametric design procedure of the linear proportional-integrator (PI) and lead-lag controllers are described. Then, in the lead-lag control system, the inner-loop current controller is replaced by the non-linear DP-MPC controller to form the proposed L2DP-MPC. Moreover, a comparative study between four designed controllers including the PI, lead-lag, PI-DP-MPC, and the proposed L2DP-MPC is performed from various aspects. All of the controllers are applied to the three-level active-neutral-point-clamped (3L-ANPC) AFE rectifier to evaluate the performance of each controller. The presented simulation results verify the performance, feasibility, and superiority of the proposed L2DP-MPC over the PI, lead-lag, and PI-DP-MPC methods.

The landscape of direct current (DC) solid-state circuit breakers (SSCBs) is growing and so too is the choice of primary components. There now exists a wide range of devices capable of withstanding voltage levels conducive to electrical transmission; though steady state efficiency of these devices remains a concern. Choosing primary components out of the growing selection pool can be cumbersome and prone to biased decision-making. The purpose of using a multifaceted mathematical approach to decision-making is to reduce these complications. The contribution of this paper will reduce biased decision-making when choosing primary components of SSCBs. This methodology consists of developing accurate and consistent simulation comparisons of steady-state efficiency, thermal performance, and cost of a variety of SSCB types, topologies, and solidstate device materials. The results contained within this paper demonstrate an achievable holistic approach to SSCB primary component choice.

Increasing tendency in online businesses and work from home, attracted many businesses and individuals to consider single-phase uninterruptible power supplies (UPSs). However, low power UPSs are normally incapable of operating for extended time periods. In order to extend UPS ranges, researchers integrated auxiliary energy sources to UPSs. However, integrating auxiliary power sources require additional power electronics active and passive components. This will result in low power density and bulky UPSs. To overcome this issue, multi-port converters have been proposed as an alternative to employing multiple converters. Nevertheless, using multi-port converters require more advanced control methods. This paper proposes a novel multi-port UPS with a finite control set model predictive controller. Simulations are conducted to demonstrate the effectiveness of the proposed converter. The results show the load current THD of 0.77%, resilient transient response, and efficiencies up to 97.5% using SiC MOSFETs.

Multi-port power converters have gained attention in renewable energy applications due to their higher power density caused by fewer number of components. Three-port converters (TPCs) provide desirable solution to many applications combining renewable energy sources (RESs) and energy storage systems (ESSs). This paper proposes a new TPC with an adaptive variable-frequency PWM (VF-PWM) control scheme to assure its operation in boundary current mode (BCM). The proposed TPC provides a feasible solution to combine a PV with a battery system for residential PV systems. This paper discusses the proposed TPC and its operation modes. Moreover, the suggested VF-PWM method is introduced to achieve BCM of the proposed TPC. The provided simulation results verify the effectiveness and feasibility of the proposed TPC and its VF-PWM method for BCM operation. Quantitative discussions on benefits of BCM from various aspects are also presented.