Elevator energy-saving equipment suppliers remind you that the elevator adopts a traction structure, which maintains balance through the counterweight, allowing the passenger car to run smoothly under the traction of the traction machine. Elevators have three working conditions: standby, drive, and regeneration (feedback). When the elevator is not running in a stationary state, it is in standby mode; When the elevator is in a heavy load up or light load down state, the external electrical energy is converted into the potential energy of the car through the rectification and inversion of the frequency converter, the operation of the traction machine and traction system, which is the driving condition; On the contrary, when the heavy load goes down or the light load goes up, the potential energy of the car is released, or the energy is fed back to the grid through a bidirectional frequency converter, or the energy is consumed in the braking resistor of the frequency converter, which is a regenerative (feedback) condition.
1. Standby mode:
Elevators do not work continuously, and the standby time is usually much longer than the time the car runs up and down. Therefore, the power consumption of standby conditions cannot be ignored, and there will be considerable losses. In standby mode, a portion of the electricity consumed by the elevator is consumed in the control and display circuits of the machine room, elevator car, and landing station, while another portion is consumed in the lighting and exhaust facilities of the elevator car.
2. Driving conditions:
In driving conditions, in addition to the consumption in standby conditions, the electricity consumed by elevators also includes the following aspects: first, power consumption of opening and closing doors; The second is the loss of the frequency conversion device, which includes all circuit losses between the three-phase power input and the inverter output in the main circuit, including filters, rectifiers, and inverters; The third is the loss of traction machine, including the loss of internal mechanical transmission of traction machine; The fourth is the loss generated by the traction system, including the energy loss during the entire process from the rotation of the traction wheel to the operation of the car driven by the traction wire rope. Electricity undergoes a series of losses before being converted into the kinetic and potential energy required for elevator operation. It should be noted that due to the role of the "counterweight mechanism", the power consumption of traction elevators varies greatly under different load conditions, resulting in significant differences in energy efficiency under different load conditions.
3. Regeneration condition:
The energy flow under regeneration conditions is relatively complex. On the one hand, the electrical energy consumption of the elevator is converted into partial kinetic energy (W motion) of the car and load through the frequency converter and traction machine after the door opening and closing motor, control and display circuit; On the other hand, the potential energy (W potential) of the car and load is partially converted into kinetic energy (W motion) of the car and load, and another part is fed back to the frequency converter through the traction system and traction machine. For elevators with energy feedback function, the frequency converter will feedback this energy (E-back) to the grid through inversion and filtering. For elevators without energy feedback function, this energy will be consumed in the cooling resistor of the frequency converter.