All-solid-state control device and method for star-delta soft handover of three-phase motor winding

Abstract

The invention discloses an all-solid-state control device and method for star-delta soft handover of a three-phase motor winding, belonging to the technical field of motor and movement control. The device comprises a detecting unit, a singlechip control unit, a driving control unit, a triggering unit, a contactor, controllable silicon, other elements of a main circuit and a connecting wire, wherein the detecting unit is connected with the singlechip control unit, and is used for acquiring and processing an electric analog quantity signal for a singlechip; the singlechip control unit is used for outputting a command to the driving unit and the triggering unit, and controlling the contactor and controllable silicon respectively; and the contactor is connected with the motor three-phase winding after being connected in series with the controllable silicon to construct star connection and angle connection. The control method comprises the following steps of: judging star connection or angle connection by detecting and calculating a load rate beta with the singlechip control unit; transmitting a signal to the triggering unit; and controlling the controllable silicon to realize star-delta soft handover according to a soft handover triggering control strategy, so that current and torque impact in the star-delta handover process can be restrained in a short period of time.

Description

technical field [0001] The invention belongs to the technical field of motor and motion control, in particular to an all-solid-state control device and control method for star-angle soft switching of three-phase motor windings. Background technique [0002] Three-phase motor star-delta switching is a simple and easy-to-implement voltage regulation and energy-saving technology, which is mainly used in motors whose load often changes between light load and heavy load. [0003] Existing star angle switching devices are generally divided into two types. One is the traditional star-delta switching device, that is, the star-delta switching is realized by controlling the off and on of the contactor by a single-chip microcomputer. When this device performs star-delta switching of the motor, the arc light of the contactor is likely to cause a short circuit, the safety and reliability are poor, and it cannot meet the requirements of fast switching. The other is to replace the contac...

AI Technical Summary

Problems solved by technology

This device adopts the strategy of simultaneous conduction of the three phases of the thyristor when switching the star angle of the motor, which meets the requirements of fast switching, but there will still be a large inrush current on the stator side of the motor.

The generation of inrush current will cause power loss

When applied to loads that require frequent star-angle switching (such as beam pumping units, conveyors, hoists, and crushers, etc.), the large power loss caused by frequent current impacts will make star-angle switching more energy-saving. get very low

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