Power electronics: evaluating off-the-shelf power conversion components

Power conversion systems can be challenging to design and build if power electronics are not a core area of expertise for your company. Before you commit to a less-than-ideal, off-the-shelf (OTS) power conversion component or launch into a costly custom power electronics design project, it would be helpful to learn how to effectively evaluate OTS power conversion components to decide what’s right for your application.

Before you start to evaluate OTS power conversion components, it’s important to determine if there are viable commercial or industrial OTS power electronics products available to fit your application. Companies with little or no experience in power electronics often make the mistake of thinking “it’s just a converter or motor drive – how difficult can it be to find something that’ll work?” The answer can often be “surprisingly difficult” if your requirement is unique or specialized.

For example, if you’re in need of a DC/DC converter for a solar panel project, it may be subjected to harsh environmental conditions and is likely needed to operate reliably for an extended period. The converter isn’t something you want to skimp on or choose because “it’s good enough” – a poor quality power conversion component will be one of the first things to fail in your system.

Let’s say you’re fortunate and you’ve identified some OTS power conversion components that appear to meet your specific requirements. Now you’re ready to thoroughly evaluate them. To ensure an OTS component will safely and efficiently work for your power electronic project, you should answer the following questions:

1. Does it satisfy your input and output requirements with sufficient margin?
2. Will it function efficiently and reliably with your min/max operating temperature range?
3. Is the cooling system appropriate?
4. Does the packaging fit your design needs?
5. Will it stand up to shock, vibration, and weather conditions?
6. Does expected product life satisfy your applications requirements? Is it within my budget?
7. Am I overpaying for OTS functions my application doesn’t require?

If a negative answer to any of these questions disqualifies a straight OTS solution, then you’ll need to determine if it can be modified to meet your requirements and if there is a commercial vendor (OEM or third party) willing and able to modify the existing OTS product or if a custom, application-specific design is necessary.

Perhaps even more important, are the vendors willing and able to support their design modifications as you move forward with your power management project? This last question can be critical for any power electronics project that could include some form of OTS power components. Many vendors simply won’t modify standard products, and if they do, they often struggle to support anything that deviates from the standard.