Advantages of Grid-Connected Source for High Power Testing

Powertech’s High Power Laboratory is a grid-fed testing facility, hosting a much stiffer power source compared to the more common, local-generator-sourced power testing facilities elsewhere in the world.

Test standards specify minimum peak and/or rms values for applied high-current waveforms with durations from a few cycles up to several seconds. As a result of their inherently decaying output, generator-fed sources may need to overshoot these minimum requirements early in the test to ensure still meeting them at the end. So, to satisfy the intent of the standard, the equipment under test may suffer unfair exposure to higher-than-intended wear-and-tear for its rating—e.g., higher electromagnetic fields, forces, and/or heating caused by currents exceeding the rating by up to 10s of percent.

Another advantage of grid-sourced power can be better on-demand availability for repeated testing. It may take a considerable amount of time to ramp up the test generator again to precisely the right speed for the next test in a series, whereas grid-sourced power is readily available in a much shorter time. A good example is capacitor switch testing, where Powertech’s High Power Laboratory is much more efficient and sometimes the only practical solution to meeting the standard testing requirements.

Testing that addresses designers’ needs to verify behavior of high-current-carrying and high-current-sensing devices in the presence of substation transients is also of particular importance in the product development phase—i.e., in prototype and proof-of-concept verification testing—where finding design margins is critical in the optimization, and possibly even direction, of technology and product development.