Monitoring aids testing of electric and hybrid vehicles

In recent years, the hybrid/electric vehicle market has been growing rapidly, and with this numerous R&D projects in the UK.

Zytek's electric Smart car was the first project to utilise Baker Instrument's AWA winding analyser, used for testing the electric motor's insulation system.

Since then, numerous Baker test units have been sold to other companies, including several F1 KERS projects, hybrid buses, taxis and coaches.

Testing in these situations ensures the motors that are produced, perhaps by a third party, are able to withstand the rigours of everyday use once fitted into a vehicle, where subsequent removal and repair can be a complex task, and damaging to reputations.

F1 KERS - driving progress
In the case of KERS, the motors can be tested trackside, before and after qualifying sessions and races, to ensure the insulation system is not compromised.

The loss of KERS during a race can be the difference between winning the race, a podium finish, or scoring points.

In 2013, possible new F1 regulations may call for higher powered KERS systems, meaning that the motors will be worked closer to their design limit, and thus run hotter. Since heat is the main cause of insulation degradation, advanced insulation testing will be critical to ensure motor reliability.

The Baker AWA tester is used to test the entire insulation system of the motor.
This includes a winding resistance test, a meg-ohm test, a DC hipotential test (or step voltage test), and a surge test.

Surge test defines the AWA
The company says: “The surge test is the most important test offered, as it is able to detect weak insulation between turns, coils and phases prior to the motor displaying any symptoms of the fault.

“The Meg-ohm test is widely used for testing motors, but this test cannot detect weak insulation, turn to turn.”

Baker testing systems for both on line (live) and off-line (bench) testing are in use world wide and are represented in the UK and Ireland by Whitelegg.