Redundant medium-voltage AC-DC-AC frequency conversion device for double-winding synchronous motor of mine hoist

Abstract

The invention discloses a redundancy medium voltage alternating current-direct current-alternating current frequency conversion device of a duplex winding synchronous motor of a mine hoist, wherein the redundancy medium voltage alternating current-direct current-alternating current frequency conversion device is mainly applied to an alternating-current low-speed synchronous motor, being below 2500KW but above 3KV, of the hoist. The redundancy medium voltage alternating current-direct current-alternating current frequency conversion device comprises a high-voltage wire, a transformer, a motor winding, frequency conversion units and an excitation unit. Each frequency conversion unit comprises an AFE rectifier, a direct current bus and an inversion unit. The frequency conversion units and the excitation unit are designed as two parallel devices which are completely the same in structure. A motor stator is of a duplex winding structure. When the two frequency conversion units work at the same time, each frequency conversion unit supplies the corresponding winding of the motor, and loads are averaged. When only one frequency conversion unit works, the windings of the motor stator are connected in series or parallel through a shift switch, and full-load half speed or full-load full speed is achieved. The redundancy medium voltage alternating current-direct current-alternating current frequency conversion device has the advantages that the structural design is reasonable, practicability is high, and due to the arrangement of the redundancy frequency conversion units and the excitation unit and due to the duplex winding structure of the motor stator, the emergency meeting performance and working efficiency of a system are improved.

Description

technical field [0001] The invention relates to an AC-DC-AC frequency conversion device with double windings of a motor, in particular to a redundant medium-voltage AC-DC-AC frequency conversion device for a double-winding synchronous motor of a mine hoist. technical background [0002] At present, DC speed control still occupies a dominant position in hoist speed control systems below 2500KW, but DC speed control systems have disadvantages such as large harmonic content and low power factor. In these aspects, AC-DC-AC frequency conversion speed control systems are obviously superior DC speed regulation, but currently there is no medium-voltage AC-DC-AC frequency conversion speed control device that can be used for low-speed AC synchronous motors in hoists below 2500KW, and there is no corresponding system redundancy solution. When the frequency conversion device fails, it must be stopped and eliminated The normal operation of the hoist can only be restored if the correspond...

AI Technical Summary

Problems solved by technology

[0002] At present, DC speed control still occupies a dominant position in hoist speed control systems below 2500KW, but DC speed control systems have disadvantages such as large harmonic content and low power factor. In these aspects, AC-DC-AC frequency conversion speed control systems are obviously superior DC speed regulation, but currently there is no medium-voltage AC-DC-AC frequency conversion speed control device that can be used for low-speed AC synchronous motors in hoists below 2500KW, and there is no corresponding system redundancy solution. When the frequency conversion device fails, it must be stopped and eliminated The normal operation of the hoist can only be restored if the corresponding failure is corrected.

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