Accelerated Life Testing
The reason for performing accelerated life testing is to determine if the motor will run for the duration of the manufacturer's projected lifetime of the unit.
To perform this testing, it is necessary to set up the motor to run like it would in the generator. For our system, there would need to be 2 motors where one drives the other so one would function as a motor and one would function as a generator.
The total run time of the test would be dependent on what the manufacturer determined is the lifetime of the motor, which in the case of the original motors in the generator would total up to 42 days. To simulate the fact that the motor would not be constantly running it would be necessary to schedule on and off periods for the motor, which would add more time to the total testing time. A conservative On-Off cycle would be 5 days On and 2 days Off per cycle, which would add 12 more days onto the total test time.
The motors would be set up under ambient conditions to generate a baseline result to do future comparisons.
The next step in the life testing would be to test the motors under the environmental conditions that they will be exposed to in the locations they are used in. This would be done using an environmental chamber with temperature and humidity controls. There is a lab located in the Center for Integrated Manufacturing Studies that has several of these testing chambers in varying sizes.
The motors would run the same was as they would under ambient conditions, but the difference here being that they would be exposed to a temperature between 120 to 160 degrees Fahrenheit and a humidity level between 50 - 75 percent. These conditions were chosen based on the weather data for the regions the BWM is used in.
To make the most efficient use of time, it would be necessary to run all tests in tandem, resulting in 6 separate setups. One ambient condition set up and one environmental specific set up for each motor, the old motor and both of the new proposed motors. Data would need to be taken daily via data logger during the On portion of the test cycle of the motors.
Due to set backs and time constraints the testing outlined above ultimately was not feasible for our project. With only one operational motor from the original motors for the generator (one having been taken apart and the other four soldered into the generator) we were unable to set up the motor to run as a generator. We were unable to do any testing with the new proposed motors either due to the motors arriving too late for testing to be completed. Ultimately we hooked up the one motor to a power supply and set it to run inside one of the environmental chambers at 120 degrees Fahrenheit and 50% humidity.
We reduced the total test time to 10 days, with a 72 hour On period, 24 hour Off period, 48 hour On period, 24 hour Off period, and a final 72 hour On period. We determined that there had been no noticeable effect of the environmental conditions on the motor itself.