The electric motor is broken. What's the reason?
Turn the handle and turn the motor at high speed without load. It is more than 10s. After the speed of the motor is stable, begin to observe and record the maximum value of the meter at this time A2.The no-load current of motor =A2-A1When the no-load current of the motor is greater than the limit data of the reference table, it shows that the motor is out of order. The reasons of large no-load current of motor are: (1) internal friction of motor. Local short circuit of coil. Demagnetization of magnetic steel. We continue to do the relevant test and inspection items, we can further determine the cause of the failure or fault location.
Analysis of six causes of motor failure of electric vehicle:I. the no-load current of the motor is largeThe multimeter in DC 20A gear, the red and black pen are connected to a power source input controller. Turn on the power and record the maximum current value of the meter at the time the motor does not rotate. A1.
1.5 、 the no-load / load speed ratio of the motor is greater than twoTurn on the power, turn the handle, make the motor rotate at high speed and no load, more than 10s.When the speed of the motor is stable, the maximum speed of the motor is measured at N1 with a hand-held speed / speed meter.In the standard test conditions, traveling above 200m distance, began to measure the maximum load speed of motor N2.Load / no-load speed ratio of =N2 / N1When the motor no-load speed / load ratio is greater than 1.5, indicating the motor magnet demagnetization has been quite severe, should replace the motor set inside the magnet, in the process of practical maintenance of electric vehicles in general is the replacement of the entire motor.
