From Concept to Compliance: Understanding EMC Risk in Future Propulsion Systems

Min Zhang, PhD

As future propulsion systems continue to push towards higher power, higher power density, higher efficiency, and reduced size, the industry has good reason to be excited about what lies ahead. The adoption of high-speed switching devices such as GaN and SiC is enabling products with significantly improved performance, efficiency, and functionality.

However, beyond the PowerPoint pitches and technology roadmaps, engineers and engineering managers alike understand one fundamental reality: at the end of the development cycle, the product must be sold into the market. This is where product compliance becomes critical. Among the various compliance requirements—such as safety, cybersecurity, and functional safety—electromagnetic compatibility (EMC) often proves to be the most challenging.

When EMC is not addressed early and strategically, solutions tend to be reactive and costly: bulky filters, repeated design iterations, expensive re-testing, and re-qualification cycles. The consequences are well known—budget overruns, delayed time to market, and in severe cases, existential risk to the business. The author has supported multiple companies that were pushed to the brink of financial failure due to unresolved EMC issues late in their development programs.

So what can be done? Especially in the early stages of development, there is an old saying: fix the roof while the sun is shining. From an engineering and management perspective, the question becomes how to identify, manage, and reduce EMC risk early in the product development cycle. This article shares several high-level principles to help both engineers and engineering managers navigate EMC risk more effectively.

1. Understanding EMC Standards

At first glance, understanding EMC standards may appear straightforward—but in practice, it rarely is. Many engineers attending my one-day introduction to EMC course discover that they have little clarity on how EMC standards actually work or how they apply to their products.

The first step is understanding which standards apply to your industry. For example, automotive powertrain modules typically need to comply with CISPR 25 for emissions and relevant ISO standards for immunity. In aerospace, DO-160 is essential. Defence projects may require compliance with UK Defence Standards or the more widely adopted U.S. MIL standards. For EV chargers, while there are charger-specific standards, a solid understanding of CISPR Class A and Class B requirements is a necessary foundation.

The key point is not just knowing what standard applies, but why EMC compliance is required and how challenging it can be to achieve. Without this awareness, engineering teams can easily fall into the trap of completing a design first and attempting to “fix EMC” afterwards—often with limited success and high cost.

2. Planning EMC into the Design Review Process

Figure 1 illustrates the importance of integrating EMC considerations into the design review process. If EMC is only addressed at the formal test stage, it is already far too late. The most effective approach is to schedule EMC reviews as early as the concept phase.

Early engagement brings disproportionate benefits. For example, an EV charging company may be evaluating three or four possible topologies, each with its own advantages and trade-offs. EMC performance should be one of the decision criteria at this stage. Otherwise, a topology selected for compact size and low weight may later require heavy filtering or shielding to pass EMC tests—completely undermining the original design goals.

From a management perspective, early EMC reviews are not about slowing innovation; they are about preventing avoidable rework and protecting program timelines and budgets.

3. Test, Test, Test

Testing does not automatically mean booking time at an accredited EMC laboratory—and incurring significant costs. While formal compliance testing is unavoidable, there are many low-cost, high-value tests that engineers can perform as soon as early prototypes are available.

Surprisingly, many teams remain unaware of how much insight can be gained from basic pre-compliance testing. Today, spectrum analysers, oscilloscopes, near-field probes, and other pre-compliance EMC tools are far more affordable than they once were. A modest investment in such equipment can provide early visibility of potential EMC risks and dramatically reduce surprises later in the program.

 The message is simple: test early, test often, and use testing as a learning tool—not just a pass/fail gate at the end of development.

Final Thoughts

Raising awareness of EMC risk and addressing it early can significantly improve the likelihood of achieving first-time compliance. Many organisations do not have in-house EMC expertise, and that is not uncommon. In such cases, engaging an experienced EMC specialist early in the development process is often a cost-effective and risk-reducing decision.

By treating EMC as a design and risk-management topic—rather than a late-stage compliance hurdle—engineering teams and managers can move from concept to compliance with greater confidence, fewer surprises, and better commercial outcomes.