This paper presents a deep reinforcement learning (DRL)-based supervisory control strategy, implemented using the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm, for voltage regulation in a DC microgrid (DCMG) supplying electric vehicle (EV) charging loads under emergency evacuation conditions. EV charging demand is modeled as timevarying constant power loads (CPLs), introducing negative incremental impedance effects that challenge voltage stability under rapid demand variations. The proposed TD3 agent regulates the duty cycles of both boost and buck converters based on system states and real-time EV charging power. Simulation results on a nonlinear averaged DCMG model show that the proposed approach maintains bus voltages within tight bounds around nominal values and outperforms a conventional droop/PI controller in terms of disturbance rejection and recovery under high EV charging demand conditions.

Large-scale electric vehicle (EV) charging during emergency evacuations can place considerable stress on power systems when demand surges are compounded by degraded network conditions. Existing optimal power flow (OPF) formulations typically neglect the flexibility and priority of EV charging under emergency conditions. This paper proposes an EV-aware DC OPF framework in which aggregated EV charging is modeled as a prioritized controllable load. A priority-based curtailment mechanism is integrated into the formulation to enable selective reduction of non-critical charging while preserving system feasibility and ensuring service to critical demand. The proposed approach is evaluated on the IEEE RTS 24-bus system under evacuation-driven demand and contingency conditions. Results demonstrate that coordinated EV charging eliminates involuntary load shedding, maintains system feasibility under stressed operating conditions, and preserves high-priority charging services by leveraging demand flexibility within the OPF framework. These improvements enhance power system resilience under emergency conditions.

Electromagnetic interference poses enormous challenges for feedback-controlled systems, especially at medium-voltage levels. As power converters are increasingly utilized for medium- and high-voltage applications, optically-based measurement methods must be explored. This paper investigates current measurement via electroluminescence from silicon carbide semiconductor devices. A SiC half-bridge MOSFET module, provided by Powerex, is manufactured with fiber optic cables placed against the semiconductor junctions. The new fiber ports are employed to characterize the light spectrum as a function of conducted current and junction temperature for the body diodes. Most of the light energy is concentrated around peaks at 390 nm and 500 nm. It is observed that although the energy at the 390 nm peak increases with rising temperature, the energy at the 500 nm peak decreases. Therefore, the total light output is seen to only slightly vary with temperature and mostly depends on conducted current. A function is fitted to the light transducer output as a in relation to the on-state current. This function is utilized in a microprocessor that implements feedback current control in a buck converter. This type of control forms the basis of torque regulation in a motor drive or an "inner-current loop" of motor drive speed control or converter voltage control. The new electroluminescence control was demonstrated in the laboratory on a prototype system where the current command is stepped from 0 to 25A, showcasing the effectiveness of the new optical sensing method.

Heat pumps are often mandated and installed in new construction. Further, existing air conditioning units are now being replaced with heat pumps for winter heating use. There are a variety of options from straight heat pump use for heating to augmentation with carbon-based fuel heaters as well as simple resistive heating. The temperature data and energy price for a particular region will determine the basic cost profile and breakpoints for transitioning or augmentation. However, carbon minimization will likely not align with the minimizing of operational costs. This paper first examines a number of scenarios utilizing data gathered from two facilities which gives the reader some options based on desired parameters of optimization. This may be particularly useful if there are government energy credits available for all-electric and solar or carbon mandates that must be met. The paper places much of its emphasis on practical solutions.

Instability problems caused by constant power loads as a result of the negative impedance effect are dealt with in this article. A comprehensive nonlinear model of a single-bus DC microgrid is developed, and a model predictive controller is designed to enhance voltage stability and optimize power management based on the developed model. Conventional control layers are replaced by a simplified optimal controller in the proposed approach in the presence of various load types, including constant power loads. Furthermore, the model and control strategy are extended to the multi-bus DC microgrid. Extensive stability analysis, including root locus methods and time-domain simulation, has been conducted in MATLAB/SIMULINK. The results confirm the effectiveness of the designed controller in maintaining system stability and improving performance under different operating conditions.

The objective of this work was to design a motor drive for electric aircraft propulsion using commercial-off-the-shelf components with a power density above 50 kW/ kg. A three-level flying capacitor topology was selected and co-simulated with the motor design in detail. The mechanical design was carried out including the thermal management system. This design involved custom-built aluminum laminated buswork. A single-phase prototype was constructed with SiC MOSFET modules and tested up to the designed dc voltage of 1.8kV. It was necessary to increase the gate resistance to improve the electromagnetic compatibility. The thermal management system design involved a loop of the cryo-cooled motor and thus the MOSFET junction temperature could be regulated to room temperature at rated operation. The power density of the motor drive was calculated to be 60 kW/ kg.

In this paper, a multi-objective optimization problem of sizing and siting power systems with the integration of electric vehicles in a distribution system is addressed. Vehicle-to-grid contribution, charging stations, renewable energy sources in the form of photovoltaic and wind turbines, and energy storage systems are considered in the proposed approach. A mixed-integer linear programming model is presented for this problem, which minimizes the total cost associated with infrastructure development and power generation while considering operational efficiency and sustainability considerations. A strategic placement of such infrastructural arrangements and their sizes can improve grid resiliency and optimally host a high penetration of electric vehicles, along with integrating renewable energy sources, is also proposed. The suitability of the proposed model is proven through a case study presented for an IEEE 24-bus distribution power system, drawing improvements in cost effectiveness, energy efficiency, and renewable energy utilization within the power grid.

In this study, a 1 MW double-rotor flux switching machine is designed for high-power density electric motors in all-electric aircraft. The motor features an air core stator that accommodates armature windings and field coils. Armature conductors utilize aluminum Litz wire at T=20K, while YBCO superconducting tapes are employed for the field coils operating at T=20 K. The inner and outer rotors are constructed with laminated Hiperco 50. Most notably, superconducting magnetic shields are positioned between the two rotor teeth to minimize leakage flux and guide magnetizing flux on a pre-determined path. This new motor is shown to have widely superior power density and efficiency. The motor design is evaluated across different pole/slot combinations, revealing that higher pole numbers increase power density. Specifically, a 20-pole/15-slot double rotor flux switching motor with a shield achieves a power density exceeding 100 kW/kg, with efficiency reaching up to 99.5%. This was twice the power density of a comparable design without the shield. The thermal management system has been designed for the proposed motor. The result is a machine that satisfies requirements for electric aviation propulsion applications.

The rapid increase in the adoption of Electric Vehicles (EVs) and Zero-Emission Vehicles (ZEVs) in California has led to significant changes in transportation infrastructure, power systems, and power distribution networks. In the first quarter of 2024 alone, 102,507 EVs were sold in California, with total sales for the year projected to exceed 410,000 vehicles if current trends continue. This shift necessitates policy changes, particularly in evacuation procedures. Traditionally, evacuation plans have assumed that evacuees use gasoline vehicles, ignoring the unique challenges posed by EVs and ZEVs, such as the need for charging and potential impacts of power outages. This study introduces the ZEV Evacuation Readiness Score (ZEV Score), a metric designed to evaluate how well a community can respond to an evacuation scenario involving ZEVs. The effectiveness of the ZEV Score is demonstrated through a case study of Santa Cruz County California, highlighting its potential application for stakeholders and policymakers.

The paper presents a cost-effective four-leg inverter designed for controlling five-phase permanent magnet synchronous motors (PMSMs). One of the five phases of the PMSM is connected to the midpoint of the DC voltage sources. The paper includes the mathematical model of the four-leg inverter, as well as the discrete model of the five-phase PMSM. Additionally, it introduces model predictive direct torque control and model predictive direct flux control for motor speed regulation. The effectiveness of the proposed drive and control method is demonstrated via simulation results.

In this paper a fault-tolerant isolated dc-dc converter is proposed for shipboard power applications. In this topology, an active 5-level T-type converter is used on the primary and secondary sides of a high-frequency transformer. The operation of the proposed converter is optimized based on minimizing the losses. A fault-tolerant analysis is carried out for this converter and post-fault switching methods are proposed for each faulty condition. The proposed converter features better fault tolerance options and higher efficiency compared to the common dual active bridge dc-dc converters. Finally, the operation of the proposed structure in the normal and faulty conditions are verified through experiments.

The increasing demand for high-power density motors in electric transport industries opens a new research opportunity to develop motor topologies with less weight and high efficiency. In particular, all-electric aircraft applications require very high power density motors. This paper shows the design of a new 1 MW 20-pole/15-slot double rotor flux switching machine with high-temperature superconducting field coils and thermal management system. The proposed motor features an air-core stator. Aluminum Litz wire is used for the armature conductors, and the YBCO- high-temperature superconducting material is used for the field coils. The armature winding and field coils operate at 95K and 65K, respectively. The active part power density including rotors, armature windings and field coils obtained with the proposed design is 29.3kW/kg. The specific power density of proposed motor considering mechanical, support structure and TMS is about 18.5 kW/kg. The efficiency can be higher than 98.7% which satisfies the requirement of electric aviation.

In this study, a 1 MW 16-pole/12-slot double-rotor flux switching machine is designed which uses superconducting magnetic shields and high-temperature superconductor field coils. The proposed motor comprises an air-core stator that carries both armature and field windings. Aluminum Litz wire at T=95K is used for the armature conductors, and yttrium barium copper oxide superconductor is used for the field coils at T=65 K. The inner and outer rotors are laminated Hiperco50, and the superconducting magnetic shields are placed between the rotor teeth. The superconducting magnetic shields have a significant impact on the machine's performance, including output power density and efficiency. The motor with shields delivers a high-power density greater than 64 kW/kg and an efficiency of ≥98.83%.

Due to the rise of electric mobility, there is an increasing need for novel and efficient electric motor designs. In particular, high power density is needed for all-electric aircraft applications. This paper introduces a new double-rotor flux reversal motor topology with an air-core stator, high-temperature superconducting field coils, and superconducting magnetics shields. Yttrium barium copper oxide is utilized for the field coils at T=65 K, and aluminum Litz is used for the armature windings at T=95 K. With the proposed design, a power density of 41 kW/kg is achieved, and efficiency at nominal power is greater than 98.87%.

This chapter presents a brief discussion of solid-state dc circuit breakers followed by a description of the Z-source circuit breaker. The primary distinction of this breaker is that it automatically responds to a fault, not requiring fault sensing circuitry. This is accomplished by a Z-source impedance network which was introduced in the power electronics arena in the early 2000s. The basic principle of operation is described followed by popular variations that have appeared in the literature. Z-source breakers with coupled inductors are then illustrated. It turns out that the coupled-inductor versions have many advantages such as the ability to tune the sensitivity to a fault using the turns ratio and also require fewer passive components. Finally, the incorporation of the Z-source breaker into power converters is shown. Examples of a buck and boost converter with built-in Z-source breakers are presented.

In this article, a bidirectional isolated dc–dc converter is proposed for application in shipboard power systems. In this topology, an active 5-level T-type converter is used on the primary and secondary sides of a high-frequency transformer. The operation of the proposed converter is optimized based on minimizing power losses. For the optimization, the transformer core loss, reactive power, and rms current are considered. Wide band gap devices are used for the minimization of semiconductor switching losses. A control method based on the Fourier series and decomposition theorem is proposed. The proposed converter features higher efficiency, fault tolerant capability, and smaller filter size compared to the common dual active bridge dc–dc converters. To reduce voltage overshoot, a laminated dc-link is designed and a two-level turn- off method is used for operating frequencies around 75 kHz. Finally, the step-up and step-down operations of the proposed structure are verified through experiments.

This paper presents an ac version of the popular dc Z-source circuit breaker. The Z-source breaker is distinctive in that it has a negative current transfer characteristic. That is, an increase in output current on a short time scale will cause a sudden decrease in input current. Therefore, the Z-source breaker can react to a fault in microseconds which is also valuable in some ac applications. After introducing the schematic and operation of an ac Z-source circuit breaker, the SCR gating method is described. This turns out to be more involved than for the dc circuit breaker because of gating requirements for additional SCRs in the circuit. Detailed simulation validates the proposed ac circuit breaker over four quadrants of positive and negative voltage and current at the time of the fault.

This paper describes and displays an advanced demonstration model of a medium-voltage dc reduced order system which contains six partial electrical zones of a ship. The model has two anticipated purposes; to assist in the determination of necessary high-speed breaker locations and to be considered a baseline for future medium-voltage dc integrated power systems with pulse loads and energy storage. The model is suited for system analysis and contains the global apparatus for reconfiguration control. The system model was constructed using average-value power electronic components with minimized controls. The impedances between subsystems as well as the internal component impedances were kept intact to assist in the evaluation of high-speed breaker placement, and utilization.