Frequency conversion system of elevator

Abstract

Provided in the invention is a frequency conversion system of an elevator. The frequency conversion system is composed of a three-phase power supply, a three-phase motor, an energy feedback device, a frequency converter, a control circuit, a bus capacitor and an energy consumption device. The frequency converter includes three first triodes and three second triodes. The energy feedback device feeds energy generated by braking of the three-phase motor back to the three-phase power supply. When the voltage of the bus capacitor exceeds a security value, the energy consumption device works. When power of an elevator is cut off and secure evacuation is carried out, the control circuit controls the three first triodes in the frequency converter to be disconnected and the three second triodes to be connected simultaneously, so that three input terminals of the three-phase motor are in a short-circuit mode. Therefore, functions of energy feedback and braking are integrated into one. Operation noises of the elevator can be eliminated; the service life of the product is prolonged and security of the product is improved; the size is reduced; and the cost is lowered.

Description

technical field [0001] The invention relates to the field of electronic power, in particular to an elevator frequency conversion system integrating energy feedback and star blocking functions. Background technique [0002] Elevators are vertical transportation equipment that convert electrical energy into mechanical energy to transport loads. According to the statistics of my country's special equipment authorities, the growth rate of elevators has remained above 15% in recent years. Because the electricity consumption of elevators is extremely considerable, especially in large buildings such as office buildings and hotels. Therefore, for elevators that are running non-stop every day, it is of great significance to save energy. [0003] The elevator transports the potential load. According to the needs, the traction three-phase motor often works in the forward and reverse electric state (first and third quadrants). When the elevator transports a weight lower than the balan...

AI Technical Summary

Problems solved by technology

But this method will cause a waste of energy, and also need to add additional cooling equipment

In addition, the star-blocking function of existing elevators uses contactors to realize short-circuiting of the three-phase motor coils. This star-blocking method is not only costly, noisy, and takes up extra space, but also has a short service life.

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