A Framework of Resilience Indicators for Zero-Emission Vehicle Emergency Preparedness

SSRN Electronic Journal · 2025-01-01

Evaluation of Heat Pump Performance: Regional Facility Data Comparison of Cost & Carbon

2024-08-11

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.

Design and Comparison of Double Rotor Flux Switching Motor With HTS Field Coil With Different Pole/Slot Combination and Field Coil Materials for Aviation Applications

2024-07-27

In this paper, a 1 MW 16-pole/12-slot and 20-pole/15-slot double-rotor flux switching machine with field coils and superconducting magnetic shields are designed and compared. The 16-pole design uses yttrium barium copper oxide superconductor field coils and aluminum Litz wire armature windings operating at 65K and 95K respectively. The 20-pole design uses aluminum Litz wire for the armature windings, while one embodiment uses aluminum Litz wire for the field coils while the other design uses Bi-2212 superconductor. All motors comprise an air-core stator that carries both the armature and field windings. The inner and outer rotors are laminated Hiperco50. All motors are optimized to have maximum power density.

Closed-Loop Current Control of a SiC-Based Power Converter via Galvanically Isolated Electroluminescence Sensing

IEEE Access · 2024-01-01

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.

Double-Rotor Flux Switching Machine With HTS Field Coils and Superconducting Shields for Aircraft Propulsion

IEEE Access · 2024-01-01 · 8 citations

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.

A Very High- Power Density Multilevel Inverter Using Silicon Carbide (SiC) Commercial-Off- The-Shelf (COTS) Parts

2024-08-11

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.

A High Power Density Flux Switching Machine with Superconducting Field Coils and Shields for Aircraft Applications

2023-05-15 · 9 citations

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%.

A Partially Superconducting Flux Reversal Machine with High Power Density

2023-05-15 · 4 citations

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%.

A Double Rotor Flux Switching Machine With HTS Field Coils for All Electric Aircraft Applications

IEEE Transactions on Applied Superconductivity · 2023-04-21 · 13 citations

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.

Fault-Tolerant Dual Active Isolated DC-DC Converter

IEEE Transactions on Industry Applications · 2023-02-16 · 9 citations

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.