Anti-short circuit device of multi-stage voltage output autotransformer

Abstract

The invention provides a short circuit prevention device of a multistage voltage output autotransformer and belongs to the technical field of short circuit prevention equipment. The device comprises afirst single-pole double-throw relay J1, a second single-pole double-throw relay J2, a third single-pole double-throw relay J3 and a fourth single-pole double-throw relay J4, wherein a movable contact of the first single-pole double-throw relay J1 is connected with a load, a normally-closed contact is connected with a first voltage tap T1, a normally-opened contact is connected with a movable contact of the second single-pole double-throw relay J2, a normally-closed contact of the second single-pole double-throw relay J2 is connected with a second voltage tap T2, a normally-open contact of the second single-pole double-throw relay J2 is connected with a movable contact of the third single-pole double-throw relay J3, a normally-closed contact of the third single-pole double-throw relay J3is connected with a third voltage tap T3, and a normally-open contact is connected with a movable contact of the fourth single-pole double-throw relay J4. The device is advantaged in that voltage switching can be safely carried out, and the risk of short circuit can be avoided, that a load end is not powered off can be guaranteed, and thereby the induced potential can be eliminated.

Description

technical field [0001] The invention belongs to the technical field of short-circuit prevention equipment, and in particular relates to a short-circuit prevention device of a multi-stage voltage output autotransformer. Background technique [0002] In industrial occasions, autotransformers are often used for voltage conversion. Autotransformers generally have multiple taps, and multiple taps output a variety of different voltages to supply equipment with different voltage levels on site, or for motors. Adjust the speed. [0003] The existing multi-stage autotransformer output on the market adopts such as figure 1 The technical solution shown: input the rated voltage of AC380V, the output has four taps, which can output 30%, 50%, 80% and 100% of the rated voltage respectively, and the four taps pass through the first normally open relay K1 and the second normally open The relay K2, the third normally open relay K3 and the fourth normally open relay K4 are switched. If it i...

AI Technical Summary

Problems solved by technology

In the above traditional solution, when the output voltage needs to be converted, it is necessary to disconnect a relay first and then close a relay. For example, when converting from 30% rated voltage to 80% rated voltage, the first normally open relay K1 must be disconnected first. Then connect the third normally open relay K3, such an operation will cause the following problems: 1. If the control error, such as software BUG, ​​etc., will cause the first normally open relay K1 to be disconnected, the third normally open Relay K3 has been closed, and when the first normally open relay K1 and the third normally open relay K3 are closed at the same time, it will cause the output terminal of 30% of the rated voltage of the autotransformer and the output terminal of 80% of the rated voltage to be short-circuited directly, and the equipment will be burned; 2. In order to control problem 1, the software must set a delay after the first normally open relay K1 is disconnected to ensure that it is disconnected first and then closed. This can cause a delay in voltage switching. Further, when the load is When the inductance is used, a strong induction potential will be generated at the load end to destroy the relay

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