Power Electronics Engineer Interview Questions UK: 8 Real Questions and What Interviewers Want

Applying for a Power Electronics Engineer job in the UK? Here is what you are likely to be asked. These questions come from our Power Electronics Engineer question bank of 12 questions, written for UK employers at mid-level level.

Eight Power Electronics Engineer interview questions, and what the interviewer is thinking

1. Why power electronics, and what do you think are the biggest challenges in the field right now?

Why they ask: They want to hear informed motivation and awareness of where the discipline is heading.

2. Explain continuous and discontinuous conduction in a buck converter, and how you would size the inductor.

Why they ask: Basic topology analysis is expected from any power electronics engineer.

3. How do you choose between silicon MOSFETs, IGBTs, silicon carbide and gallium nitride devices?

Why they ask: Device selection affects efficiency, cost and reliability, and the field is moving quickly.

4. How would you estimate the losses in a converter and design its thermal management?

Why they ask: Thermal performance often limits power converters, so they want a quantitative approach.

5. What are the differences between voltage mode and peak current mode control, and how do you ensure the loop is stable?

Why they ask: Control design is central to dependable converters.

6. Which safety and isolation requirements apply when designing an isolated mains-connected power supply?

Why they ask: Safety compliance is critical for any product connected to the mains.

7. During prototype testing, a MOSFET in your converter fails the first time you apply full load. How do you investigate?

Why they ask: Failure analysis is a daily task and they want a safe, methodical approach.

8. Tell me about a power converter you designed. What were the key decisions and what would you do differently?

Why they ask: They want to see real design experience and honest reflection.

A sample answer to question 1

Why power electronics, and what do you think are the biggest challenges in the field right now?

Power electronics sits behind almost every major shift in energy: electric vehicles, renewable generation, battery storage, data centres and efficient motor drives. What attracts me is that small improvements compound, because gaining one percentage point of efficiency across thousands of units saves a great deal of energy and heat. It's also a discipline where theory meets messy reality, since parasitic inductance, thermal limits and EMI can all undo a perfect simulation. The biggest challenges I see are increasing power density as wide-bandgap devices such as silicon carbide and gallium nitride switch much faster, which brings new layout, gate drive and EMI problems; managing thermal performance in smaller packages; achieving reliability and lifetime targets, especially in automotive; and meeting safety and compliance requirements. I'm keen to work in a team where I can combine design, simulation and hands-on testing.

Common mistake to avoid: Giving a vague answer about liking electronics; Ignoring practical issues like EMI and thermals

Want the rest?

Full model answers, key points and common mistakes for all 12 questions are on the Power Electronics Engineer interview questions page. The first five are free, no sign-up needed.