Link finished installation of Zytek Automotive’s new double – ended electric drive motor test stand in July 2012. With this test stand Zytek will now be able to evaluate motor and drivetrain performance with motor power up to 180 kW and speeds up to 14,500 rpm at an input torque of up to 280 Nm. Conception, development and design of this test stand were accomplished in a time frame of 13 months.
The start-up of this ambitious test stand design for Zytek Automotive in the United Kingdom marks an important milestone for Link Engineering Company in Plymouth, Michigan. It demonstrates Link’s successful application of its versatile ProLink software suite to a drive motor test application.
The test stand will be capable to evaluate the complete performance spectrum of electric vehicle motors including the inverter and drivetrains for Zytek products. Most frequent applications are high speed and torque tests, hot temperature and cold soaked start up, durability tests, noise evaluation, dynamic torque variation, and a slew of research tests. ProLink is windows based software that is worldwide in use on approximately 1000 Link products with excellent success in its user community. The hands-on easy programmability with flexible configuration capability has become a standard for dynamometer operation, but will be again useful for the Zytek engineers because they will be able to quickly develop iterations on any test routines in minimal time.
Zytek’s machine is double-ended which makes it also suitable to either run two motors simultaneously, or set up different tests on one side while a test is running on the other side. The absorber motor is four quadrant operated, and located in the center of the massive, welded machine base optimized for torsional stiffness. It is rated for 320kW (430 hp) at 4000 rpm, and feeds its power into a 1:3.3 high speed increasing gearbox capable to rotate up to 14,500 rpm on the test motor side. Max torque translates into 280 Nm at 5400 (input) rpm.
Obviously, the high speed spindle revolutions presented lubrication challenges which were met by using oil mist lubrication, in addition, a special leak oil drainage system for the high speed gear box needed to be designed and built.
Zytek also requested a chiller that would not only allow providing constant cooling of the motor under test with a water/glycol mixture (which is also used in the actual vehicles), but soak the test article at minus 20° Celsius in order to simulate cold starts.
The power supply for the test stand consists of a 180kW battery simulator with a regenerative unit, sized large enough to handle 0 – 600V and 0 – 600A (180kW above 300V). This allows Zytek not only to take their motors and inverters through their paces, but experience what electric drive trains promise: an economical, green and sustainable method of propulsion and propulsion testing.