Thyristor assisting arc extinguishing combined type on-load tap changer

Abstract

The invention provides a thyristor assisting arc extinguishing combined type on-load tap changer. The tap changer comprises a main current circuit and a thyristor module connected with the main current circuit in parallel; the main current circuit includes a first contact switch, a main loop switch and a second contact switch which are connected in sequence; the main loop switch includes two static current guide contacts separated from each other, and a movable switch which is in movable connection with the two static current guide contacts. In the technical scheme, the thyristor module creates a thyristor triggering condition through the potential difference generated in the switch-on process of the mechanical switch contacts, triggering of the thyristor module becomes safer and more reliable, thyristor continuous current in the thyristor module is less than 12 milliseconds, arc burning is not generated in the triggering process, switch transition is smooth, and arc impact and heat are not generated.

Description

technical field [0001] The invention relates to an on-load tap-changer, in particular to a hybrid on-load tap-changer which utilizes a thyristor to assist arc extinguishing. Background technique [0002] The on-load tap changer is an important component of power voltage regulating transformers and industrial voltage regulating transformers. Through it, the tap position of the transformer can be adjusted without interrupting the load current, and then the fine-tuning of the transformation ratio can be realized to change the voltage of the transformer. Output voltage or output capacity; however, traditional on-load tap-changers will generate arcs when switching, and the generation of arcs will inevitably lead to energy loss and pollution of transformer oil. [0003] Thyristor on-load tap-changers can completely avoid arcing during gear switching. With the continuous development of power electronic devices, performance parameters and reliability indicators continue to improve. ...

AI Technical Summary

Problems solved by technology

[0004] In order to improve the safety of the thyristor switch, Zhao Gang from the School of Electrical Engineering of Xi'an Jiaotong University studied a thyristor-based arc-free on-load tap-changer, whose structure is as follows figure 1 As shown, in the low-voltage simulation test of this tap changer model, it is found that the arc extinguishing switch cannot always effectively extinguish the arc, and its arc extinguishing characteristics are related to the direction of the arc current and the status of the switch. The test also found that it is used for the bypass switch current The trigger conduction status of the forward and reverse thyristors when the switch is closed is closely related to the sequence of closing nodes 4 and 5 and the direction of the arc current when they are closed. This problem has not been solved in its open literature. Not commercially available

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