Cryogenically-Cooled Power Electronics for Long-Distance Aircraft

Abstract

New aerodynamic aircraft concepts enable the storage of volumetric liquid hydrogen (LH 2 ). Additionally, the low temperatures of LH 2 allow technologies such as the superconductivity of electrical components. An increased power density of the onboard wiring harness and the electrical machine can be expected. Nevertheless, the power electronic drive inverter has to deliver high power and high switching frequencies (f PWM s) under challenging conditions. Therefore, knowledge of the electric behaviour of different semiconductor materials under cryogenic temperatures is essential to answer the question: "Are modern power electronics a technology enabler or a system bottleneck?" This publication shows a comprehensive novelty study for cryogenic power electronics based on experimental-driven semiconductor investigations, mission profile-based considerations, requirement analyses of superconducting electrical machines, and studies of the cooling concepts. All aspects are discussed within one interdisciplinary publication. A cryogenic system cannot be considered without a feasible cooling concept. Different semiconductor structures based on various materials (silicon (Si), silicon carbide (SiC) and gallium nitride (GaN)) are evaluated for their suitability. The collected data and the literature review draw a technology feasibility studies supported by detailed cooling system analyses and superconducting electrical machine requirements. The power demand and high f PWM lead to a SiC non-cryogenic inverter approach. Due to the detailed cooling system assessment, a loss reduction is achieved by optimising the junction temperature (T J ) under various load cases (LCs) out of the mission profile.INDEX TERMS Long-distance aircraft, fuel cell, liquid hydrogen, cryogenic cooler design, high temperature superconductivity, cryogenic electrical power supply system, cryogenic power electronics, experimental semiconductor comparison, cryogenic inverter design ACRONYMS

Review, Comprehensive Analysis and Derivation of Analytical Power Loss Calculation Equations for Two- to Three-Level Midpoint Clamped Inverter Topologies with Hybrid Switch Configurations

“…In addition to the setup of multi-level inverters from different power semiconductor packaging technologies, the design of the inverter itself and the thermal management-for instance, under the consideration of cryogenic cooling [51]-are crucial. For multi-level inverters with their increased number of switch positions and offered degrees of freedom in terms of current paths, the optimization of the commutation loop is one of the primary challenges.…”

Cost optimization of electricity in energy storage system by dynamic programming

“…It involves determining the most efficient and cost-effective way to store and supply electricity while considering various factors such as operational expenses, maintenance costs, and the cost of individual components like batteries and inverters [13], [14]. Additionally, ensuring grid stability and reliable integration with renewable energy sources are essential objectives to achieve.This research paper aims to address these challenges by implementing a dynamic programming algorithm to optimize the cost of electric storage systems [15], [16]. By doing so, we seek to contribute to the ongoing efforts to make renewable energy sources more economically viable, reduce greenhouse gas emissions, and enhance the overall sustainability of the energy sector.…”

Electromagnetic Characterization of Hyperconducting Aluminum Litz Wires at Cryogenic Temperatures

“…The use of liquid hydrogen as an aviation fuel has led to increasing interest in cryogenic technologies for enhancing the performance of conductors [2] for cables, electric machines and drives [3][4][5], potentially leading to a significant reduction in conductor losses [6][7]. Regarding the winding materials for cryogenic electric machines (CEMs), two types are commonly considered: superconducting materials and hyperconducting materials.…”