Researchers have published a comprehensive review of configuration and parameter design for electrified propulsion systems in three-dimensional transportation, or TDT, covering air, ground, and sea applications. The review reorganizes the design space for electrified propulsion and proposes six design stages to guide future research on propulsion configuration, sizing, screening, and co-optimization.
Electrified propulsion is central to the transition toward lower-emission transportation. While electric and hybrid powertrains for road vehicles have received extensive attention, the electrification of aircraft, marine systems, and rail platforms introduces additional challenges. These systems often have larger, more complex propulsion architectures, stricter safety and weight constraints, and operating profiles that differ greatly from conventional ground vehicles. As net-zero emission requirements become more urgent, the design of propulsion systems must address a broader and more demanding transportation landscape.
The new review focuses on both the configuration layer and the parameter layer of electrified propulsion design. Configuration design concerns the structure of the propulsion system, including how energy storage devices, coupling devices, output types, actuators, and power elements are combined. Parameter design concerns sizing and optimization choices that determine how those components perform together. According to the article, both layers are crucial to overall vehicle performance, especially as transportation electrification expands into air, ground, and sea domains.
A major contribution of the review is its reclassification of the entire design space for electrified propulsion configurations. The authors summarize four development periods of propulsion design and analyze potential topological design space from five aspects: energy storage devices, coupling devices, output types, actuators, and power elements. This kind of reorganization is valuable because propulsion design literature can be fragmented across vehicle types, component technologies, and optimization methods.
The paper also proposes, for the first time, six design stages for electrified propulsion applications. These stages are configuration representation, comparison and modification, generation, physical layer screening, control layer screening, and configuration-parameter co-optimization. By separating the design process into these stages, the review provides a structured way to understand where different methods contribute and where challenges remain.
Each stage plays a different role in propulsion development. Configuration representation helps describe complex architectures in a form that can be analyzed. Comparison and modification support evaluation of known designs. Generation methods help explore new candidate configurations. Physical layer screening evaluates whether a configuration is feasible or promising from hardware and performance perspectives, while control layer screening considers whether the design can be managed effectively during operation. Configuration-parameter co-optimization then attempts to link structural choices and sizing decisions into a more integrated design process.
The review is also notable for its emphasis on methods rather than a single vehicle class. The design and optimization of electrified propulsion may involve tools such as dynamic programming, model predictive control, rule-based strategies, reinforcement learning, particle swarm optimization, genetic algorithms, and other approaches, depending on the stage and application. The paper?s framework helps place these methods within a broader design workflow for TDT, rather than treating them as isolated techniques.
For researchers and engineers, the review may be useful because it identifies both the strengths and limitations of existing approaches at each design stage. It also discusses challenges specific to TDT propulsion design, where systems may need to balance energy efficiency, weight, reliability, dynamic performance, emissions, and integration with intelligent transportation infrastructure. Such trade-offs are especially important when electrified propulsion must support vehicles operating in three-dimensional environments, not only on roads.
Further research will still be needed to turn this broad design framework into mature tools for specific aircraft, marine, railway, and multimodal applications. Even so, the review offers a structured guide for advancing configuration design and sizing optimization of electrified propulsion systems. As transportation electrification continues to expand beyond ground vehicles, clearer design taxonomies and co-optimization strategies could help accelerate the development of cleaner and more capable propulsion systems.
Reference
Author:
Yunge Zou a b , Yalian Yang a b , Yuxin Zhang a b
Title of original paper:
Configuration and Parameter Design of Electrified Propulsion Systems for Three-Dimensional Transportation: A Comprehensive Review
Article link:
https://www.sciencedirect.com/science/article/pii/S2773153725000362
Journal:
Green Energy and Intelligent Transportation
DOI:
10.1016/j.geits.2025.100286
Affiliations:
a The College of Mechanical and Vehicle Engineering, Chongqing University, Chongqing 400044, China
b The State Key Laboratory of Mechanical Transmissions for Advanced Equipment, Chongqing University, Chongqing 400044, China
Green Energy and Intelligent Transportation
Experimental study
Not applicable
27-Mar-2026