Evaluation and uncertainties of an electric direct-drive motor test system with a mathematical model confirmation. (14th September 2018) - Herman, J
Abstract: This paper presents and evaluates a novel system for testing direct-drive motors for the next generation of electric vehicles. The system is adjusted to determine motor characteristics and losses at high torque and medium speed with high accuracy. It is controlled by a custom-made program, which supports motor testing in various control modes and working regimes and under various testing procedures due to the modular program structure. The measurements are therefore repeatable, reproducible, and can be carried out in a short period of time. Regarding the problem of energy consumption, the proposed test system with two direct drive motors (instead of an industrial braking motor) results in additional savings. An additional contribution of the paper presents a system upgrade with the evaluation of the test system in terms of the A and B types of uncertainty and its confirmation with a motor mathematical model. One-to-one correspondence is confirmed without any mathematical model modifications in a short circuit test. A good agreement between measured values of different quantities and the mathematical model can be also confirmed with tests of motor losses, torque-speed characteristic, motor thermal behavior, and efficiency map. The presented tests are part of the testing procedure used during evaluation of the direct-drive motor.