Powering industrial electronics

Kevin Parmenter, Power Systems Design Contributor



Kevin Parmenter, Power Systems Design Contributor

Several years ago it was my privilege to be selected to write the introductory section on Industrial power for the PSMA PTR –Power Technology Roadmap.   Part of what I said about the characteristics of the industrial market was that it was as close as you can get to automotive electronics without wheels attached, and that the market goes on forever.

This is still true today.  The quality and reliability expectations of the customers in this market are very high.  Additionally the expectations for product availability – meaning assured source of supply through the supply chain can be 10 years or more. Industrial customers dislike change.  

This is completely opposed to the “driver” consumer market in which something that takes 100 Phd’s 2 years to design is soon a commodity being sold by the pound like wheat in 6 months only to be discontinued and replaced by something better fast – processors and anything in the handset market follows this trend. 

Fortunately the industrial market is not impressed by the latest new “whizzy-whiz hotness” they want long-term predictability and reliability. Industrial environments can be very hostile, electrically as well as environmentally.  Surges and transients in excess of the normal IEC specifications are routine and since the transients cant read specifications they just go ahead and destroy things anyway.  

Equipment in oil field production areas on oil rigs at sea are often powered by long runs of power mains connections and or they are lighting targets– meaning its not if a lighting strike will occur during product operational lifetime its how many times a month.  I’ve seen PCB traces vaporized off the board by transients and surges many times so external protection for the power supply inputs is often needed and rarely added! 

System cooling is often an issue.  Equipment is often in NEMA enclosures and sealed – the cabinets are very often “cleaned” by high-pressure steam hoses or salt water fire hoses.   In Machine tool and Aluminum Smelting applications the enclosures have to be to sealed to keep out metallic dust in the air from the processes. 

What about the loads?  Industrial loads are often as hostile as the environment.  If the power electronics are developed on an electronic load in the lab – the industrial loads will look nothing like this.  Industrial loads are routinely highly reactive – motors, fans – blowers, pumps, compressors, valves – solenoids, servos, large capacitor banks, battery banks and combinations of these and more on the same bus.  

The expectation is that the power supply will not have any issues with hundreds of volts of back EMF and 10’s of amps of inrush current to overcome the capacitance or get that motor spinning with the huge inertial mass starting from a dead stop.  When the motor reverses it will turn into a generator and push power back into the power source. The power systems will be expected to handle this entire all with no issues. 

The right test equipment is needed to test for all these attributes while the test market itself is considered part of the industrial market as well!  Moreover IEC60950 that has been one of the key standards for industrial power for a long time is being phased out to be replaced IEC62368-1 – likely being required in 2018.  That does not mean that there are not a plethora of other IEC and other specifications that industrial power needs to meet but this is one of the major ones.

The good news is this market is stable and if you have what it takes to participate in it, there is plenty going on and the market simply continues on despite market conditions –ups and downs and twists and turns in the electronics industry.  If you have the expertise, reputation for quality – reliability, stability and the patience to survive in it it’s a great place to be.