A Hybrid On-Load Tap-Changer and Its Transistor Triggering Method

Abstract

The invention discloses a hybrid on-load tap changer, the hybrid on-load tap changer has a tap changer main contact, a thyristor auxiliary contact and a thyristor trigger contact for connecting with a distribution transformer tap The main contact of the tap changer is connected to the voltage output terminal; the hybrid on-load tap changer includes a thyristor, a first trigger resistor and a second trigger resistor; the second main electrode of the thyristor is connected to the thyristor auxiliary The control pole of the thyristor is connected to the trigger contact of the thyristor through the first trigger resistor, the control pole of the thyristor is connected to the voltage output terminal through the second trigger resistor, and the thyristor The first main electrode of the device is connected to the voltage output end, so that passive triggering can be realized, the structure is simple, and the reliability is high. The invention also discloses a transistor trigger method of the hybrid on-load tap changer.

Description

technical field [0001] The invention relates to the technical field of on-load tap changers, in particular to a hybrid on-load tap changer and a transistor trigger method thereof. Background technique [0002] At present, the on-load tap changer used for distribution transformers is mainly a hybrid scheme of mechanical switches and thyristors. The principle of this scheme is that the mechanical contacts carry current during normal operation, and only when switching is required, the power electronic device acts to bear the current during the switching process and avoid arc generation. When this scheme is adopted, the power electronic device does not carry current for a long time, and there is no need to consider the problem of heat dissipation, and the structure is relatively simple. [0003] However, the main technical problem of the existing hybrid power electronic tap changer solution is how to realize the passive triggering of the power electronic switch. In the patent ...

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Problems solved by technology

However, in this scheme, the conduction of the thyristor is realized by the arc voltage between the contacts, because the arc voltage is actually determined by the arc current and arc resistance. When the contacts are broken, the AC current passing through the contacts is just near zero crossing. When the arc voltage is small, it may not be enough to meet the trigger voltage of the thyristor

[0004] At present, the thyristor is still triggered by the arc voltage when the contact is disconnected, or the trigger signal is provided by an external circuit to realize the thyristor trigger, which will increase the complexity of the actual product

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