Motor overload means that motors generally have a fixed operating power, called rated power, in watts (W). If, under certain circumstances, the actual power used by the motor exceeds the rated power of the motor, this phenomenon occurs. is called motor overload.
There are two main reasons for motor overload:
1. When the actual demand of the mechanical equipment driven by the motor When the power is greater than the rated power specified on the motor nameplate, it is called overload operation of the motor, also called overload operation. Indeed, the load torque is greater than the rated torque of the motor and the motor increases the electromagnetic torque by increasing the rotor current
2. The new torque and the load torque reach a new balance and. keep running. As the current of the rotor increases, the stator current increases, which leads to increased motor copper losses and generates heat. Over time, the insulation ages and even the motor burns out. However, the overload time is very short, the heat is not large, and it dissipates quickly, so the motor can temporarily withstand overload operation.
Solution:
1. When the load is too large, reduce the load appropriately or replace the electric motor with suitable power. ?
2. When the power supply voltage is too high or too low, install a three-phase power supply voltage stabilization device to compensate the voltage. ?
3. The motor has been seriously affected by moisture or corrosive gases for a long time, resulting in a decrease in insulation resistance. Depending on the specific situation, overhaul or replace the motor with the same sspecifications. ?
Detailed information:
The main symptoms of motor overload are:
1. The heat generated by the engine increases
2. The engine speed decreases and may even drop to zero; ;
3. The engine has a low hum and normal vibration;
4. If the load changes drastically, the motor speed fluctuates up and down; > Reference materials:
When When the load changes suddenly, due to rotor inertia, the rotor power angle cannot immediately stabilize at the new value, but must oscillate several times around of the new stable value. This phenomenon is. called synchronous generator oscillation.
For stepper motors, there are certain requirementsconcerning the power frequency of the windings. If the power-on frequency is too high and exceeds the maximum stepper speed of the stepper motor, lag will occur. In addition, in a synchronous motor, when the load torque of the motor is greater than the torque that the motor can provide, the speed of the motor cannot keep up with the synchronization speed of the motor, which will also cause lag.
Detailed information
There are two types of oscillation: one is that the amplitude of the oscillation becomes smaller and smaller, and the power angle oscillation gradually attenuates, and finally stabilizes at a new power angle, and still works stably at synchronous speed. , which is called synchronous oscillation; The other is that the amplitude of the oscillation becomes larger and larger, and the power angle continues to increase until it exits thestable range, causing generator loss of synchronization and asynchronous generator operation, so-called asynchronous oscillation.
The generator offset protection reflects the change trajectory of the impedance measured at the generator end, which can reliably avoid system short circuits and stable oscillations, and can distinguish out-of-synchronous accelerations and decelerations. offset during the offset swing process.
Baidu Encyclopedia - Out of Pace Protection
Baidu Encyclopedia - Out of Pace Protection