Master Thesis - Traction Power Module

Req ID:503188 

At Alstom, we understand transport networks and what moves people. From high-speed trains, metros, monorails, and trams, to turnkey systems, services, infrastructure, signalling and digital mobility, we offer our diverse customers the broadest portfolio in the industry. Every day, more than 80 000 colleagues lead the way to greener and smarter mobility worldwide, connecting cities as we reduce carbon and replace cars.

We'll look to you for: The thesis project (20 weeks) with two possibilities:

1. Systematic Identification and Mitigation of Traction Power Module Failures Using Advanced GDU Sensor Functions

Background
At Alstom’s global R&D Centre for railway electric traction systems in Västerås, the company continually develops new converter designs for greater performance, reliability, reduced losses and equipment size. This is accomplished through the effective utilization of the latest generation of power semiconductor devices (Si / SiC) in dual packaging for railway traction. The state-of-the-art Gate Drive Unit (GDU) technology is engineered to optimally control power semiconductor modules under various operating conditions. The GDU integrates advanced sensing capabilities, enabling it to monitor critical parameters such as voltage, current, and temperature, as well as to support innovative features for condition monitoring and fault detection.

Problem description and goals
The new generation of power semiconductors for traction applications are designed to last several years of hard operations. Despite this, the failure rate in real-world traction applications is higher than desired with severe consequences. Thus, early understanding and mitigation of these failures is critical for any successful traction converter business

This thesis project aims to systematically identify and prioritize critical failure modes in traction power modules, especially within Alstom’s field applications. The project will study, develop, implement, and validate early detection and mitigation strategies, integrating them into the GDU for future product enhancements.

The work includes (but is not limited to) the following main steps

1. 1. Introduction to electric railway traction converters, power semiconductors, and gate drive applications.
   2. Literature review of semiconductor failure modes in traction applications, including detection and mitigation strategies
   3. Study Return of Experience (REX) from Alstrom field application failures
   4. Assessment and selection of the most critical failure modes and corresponding mitigation strategies
   5. Development of solution architecture, including modelling and simulation as required.
   6. Implementation and testing of the selected solutions at Alstom power semiconductor laboratory
   7. Analysis, conclusions and reporting

Prerequisites: Background in electrical, electronics and/or computer engineering, basic understanding of power electronics and semiconductor switches. Knowledge VHDL is a plus but not mandatory. Good analytical skills.

2. Advanced Dynamic Modeling of Power Electronic Circuits for Railway TractionBackground
   At Alstom’s global R&D Centre for railway electric traction systems in Västerås, the company continually develops new converter designs for greater performance, reliability, reduced losses and equipment size. Accomplishing this effectively requires greater in-depth understanding of the dynamic behaviour of the complete power electronic circuitry including power semiconductor packages, main circuit and gate drives, to guide the evolution of the design in an iterative manner. This can be achieved with the more advanced modeling and simulation software such as the ANSYS Electronic Desktop.

Problem description and goals

The thesis will focus on exploring the electrical design limits of a 3-level converter topology for railway traction compared to state-of-the-art 2-level solutions. This will be done by modeling the circuits with all relevant parasitic circuit elements in ANSYS, derived from mechanical CAD models, and analysing the behaviour in various operating conditions. Furthermore, the studies are also expected to help establish a new workflow for the analysis of new and existing designs. The thesis project will be carried out and co-supervised in collaboration with Alstom’s research partner, RISE (Research Institutes of Sweden).

The work includes (but is not limited to) the following main steps

1. 1. Introduction to electric railway traction converter, power semiconductor and gate drive applications
   2. Literature study of state of the art 3- and 2-level topologies for railway traction converters
   3. Introduction to modeling in ANSYS
   4. Modeling of main circuit, power semiconductor modules and gate drive including parasitics based on geometric and material properties from CAD models etc. for selected 3-level and 2 level topologies, respectively.
   5. Simulations to explore design limits and fault case behaviours for selected circuits.
   6. Analysis and evaluation of simulation results
   7. Analysis and documentation of simulation workflow
   8. Reporting

Prerequisites: Background in electrical and electronics engineering, basic understanding of power electronics and semiconductor switches. Experience in modeling and simulation is an advantage. Good analytical skills.

You don’t need to be a train enthusiast to thrive with us. We guarantee that when you step onto one of our trains with your friends or family, you’ll be proud. If you’re up for the challenge, we’d love to hear from you!

Important to note

As a global business, we’re an equal-opportunity employer that celebrates diversity across the 63  countries we operate in. We’re committed to creating an inclusive workplace for everyone.