We know that in the variable frequency speed control system, the motor speed reduction and shutdown are realized by gradually reducing the frequency. At the moment of frequency reduction, the synchronous speed of the motor decreases, and the rotor of the motor is due to mechanical inertia. The speed has not changed. When the synchronous speed is less than the rotor speed, the phase of the rotor current changes almost 180 degrees, and the motor changes from the electric state to the power generation state; the ripple resistor is in the motor, which can protect the motor well and consume the power generated in the motor, usually the ripple resistor. The use of surface vertical corrugation facilitates heat dissipation and reduces parasitic inductance, and uses a high flame retardant inorganic coating to effectively protect the resistance wire from aging and prolong its service life.
The aluminum alloy resistor in the elevator is more resistant to weather and vibration than the corrugated resistor. It is superior to the traditional porcelain skeleton resistor. The aluminum alloy resistor is usually used in harsh industrial environment, and easy to install additional heat sink. Under normal circumstances, all major brand elevator equipment will give priority to the use of aluminum alloy resistors, which makes the elevators safer and has a longer service life.
The aluminum alloy resistance and corrugated resistance in the elevator are used in different requirements. In many cases, the elevator braking resistor can work stably for a long time. In the face of long-term and repeated use, more elevator manufacturers will use aluminum alloy resistors to make the brake resistors of the elevator, which can reduce the number of elevator maintenance, and also make the elevator safer and ensure the smooth operation of the motor.
