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Electric Motor Manufacture (QM Power)Product Development

Motor Manufacturer Needed High-Performance Power Supply for EV Applications.
Kikusui’s compact, high-capacity, variable-frequency power supply to the rescue!


QM Power develops and manufactures alternating and direct current motors, controllers, and related equipment. Before embarking on a plan for a new, more efficient motor with enhanced performance to be used in electric vehicles, QM Power rethought its approach to motor manufacture to include new technologies. QM Power also decided to relocate to a new premises to enable the development of the new motor. However, problems were in store.

The Problem

While QM Power moved premises with great expectations, an unreliable power supply made motor testing fraught with complications.

QM Power realized that the large power supply it had provided for testing purposes was unable to test its new motor properly. As things stood, QM Power had no prospect of performing precise or efficient testing.

The leader of the development team recalls─
“While we tried using mains power as an alternative, testing still didn’t go well. The unpredictable and noisy nature of the mains supply creates unexpected test results. After that, we tried using a variac to limit the voltage supplied to the device under test. However, this approach was not only time-consuming, but yielded spurious results, and tests sometimes had to be repeated. The variac also did not allow us to vary the frequency of the current supplied to the device under test. We would have liked to have had more flexibility when controlling frequency.”

When developing electric motors, it is ultimately necessary to control the voltage waveform applied to the motor being tested, to see how the motor will respond to unexpected conditions. QM Power needed to install a permanent, high-performance power solution in its new premises.

The development team began to research the problem in the hope of finding a relocatable, compact, high-output, power supply with variable frequency, that could perform both AC and DC testing.

Key Aspects of the Problem

  • The lack of a reliable, variable-voltage, variable-frequency power supply meant proper, efficient testing was not possible.

  • The unpredictable and noisy nature of the mains supply created unexpected test results.

How was this problem solved?