AC mine winder rotor frequency modulation pressure regulating apparatus

Abstract

The invention mainly provides a frequency and voltage regulation device of a rotor of an AC mine hoist. The power input part of the device consists of a rectifier transformer and a switch regulated power supply; a rectification / feedback part consists of a rectifier bridge and a current transformer thereof, a feedback bridge and a current transformer thereof, a rectifier feedback control unit and rectifier feedback trigger unit and so on; a DC energy storage part consists of a plurality of serial electrolytic capacitors which are in parallel connection; the output part of the frequency and voltage regulation part consists of an inverter bridge and a current transformer thereof, an inverter bridge control unit and a trigger unit; the AC output of the inverter bridge is directly connected with a three-phase winding of the rotor of a wound motor. When the hoist hoists heavy objects, the device outputs positive power; when the heavy objects are dropped by the hoist or the speed is reduced, the frequency and voltage regulation device transforms potential energy into electric energy which is fed back to an electric network, thus outputting negative power. The frequency and voltage regulation device replaces a metallic resistor which is serially connected outside a rotor of an AC wound asynchronous motor, and can realize stepless speed regulation control for the AC mine hoist under the energy saving condition.

Description

technical field [0001] The invention belongs to the mine hoist control technology, and mainly proposes a frequency and voltage regulating device for the rotor of an AC mine hoist, which replaces the metal resistors connected in series outside the rotor of an AC wound asynchronous motor, thereby realizing hoisting of an AC mine under the premise of energy saving. The machine is controlled by stepless speed regulation. Background technique [0002] At present, the speed regulation of the known AC hoist is carried out by changing the metal resistors connected in series outside the rotor of the AC wound asynchronous motor. Before accelerating, all the resistors are connected in series, and then the resistors are cut off step by step. Finally, the hoist runs at the rated speed; in the deceleration stage, the electric braking current (low-frequency current or DC current) must be input and the controllable deceleration can be performed with the cooperation of the external series re...

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Problems solved by technology

However, the rotor of this AC wound asynchronous motor is connected in series with resistors to adjust the speed, which mainly has the following disadvantages: 1) it needs tens to 200 boxes of metal resistors, which occupies a large area; In the process of acceleration, deceleration and lowering of heavy objects, a large amount of electric energy is consumed on the resistor, which wastes a lot of energy and does not conform to the national energy saving and emission reduction policy; 3) There is a step-by-step speed regulation, and the speed regulation performance is poor; 4) In the motor There are contacts on the stator side for commutation and braking current switching, and the reliability of the equipment is not high

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