Speed regulation control system of single-phase induction motor

Abstract

The invention relates to a speed regulation control system of a single-phase induction motor. The speed regulation control system of the single-phase induction motor comprises one or more pulse-width modulation (PWM) rectifying circuits for outputting direct current to a direct current bus, a plurality of inverting circuits connected with the direct current bus, and control circuits, voltage detection circuits, current detection circuits, rotating speed detection circuits and speed regulation switches which are connected with the inverting circuit; the bus is provided with direct current by the one or more PWM rectifying circuits; the input ends of the rectifying circuits are connected with a three-phase alternating-current power supply, and the output ends of the rectifying circuits are connected in parallel with the input end of the inverting circuit through a positive direct current bus and a negative direct current bus; and the control circuits correspondingly control the inverting circuits one to one and are connected with the speed regulation switches one to one. The speed regulation control system has high power factor and low current impact, can effectively using braking energy of the single-phase induction motor and is used for a plurality of single-phase induction motor driving systems which frequently start and stop or require speed regulation control.

Description

technical field [0001] The invention relates to a single-phase induction motor speed regulation control system, which is used for frequent start-stop or multiple motor drive applications requiring speed regulation control, and is especially suitable for electric drive of factory industrial sewing machines . Background technique [0002] At present, single-phase induction motors are widely used in various industrial and civil occasions, for example, industrial sewing machines, air-conditioning devices, ventilators, water pumps, and electric tools. Taking the current operation of machinery in garment factories as an example, there are a large number of sewing machines in garment factories, and the following problems will occur during use: [0003] For a single-phase induction motor without start control, when it is in the state of frequent start and stop, there is a current impact during the start process. The current impact will cause the instantaneous current in the motor ...

AI Technical Summary

Problems solved by technology

Large reactive power, resulting in loss of grid energy

[0005] At present, in applications such as sewing machines, there is still a way of using a mechanical clutch to control the mechanical start and stop. This way makes the single-phase induction motor often run without load, resulting in a low power factor of the system.

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