Detection circuit suitable for on-line temperature of high-voltage solid-state soft starter

Abstract

The invention provides a detection circuit suitable for the on-line temperature of a high-voltage solid-state soft starter, belonging to the technical field of the starting of a high-voltage motor, and mainly aiming at solving the problem that the existing temperature protection technology only sets the every-time starting time interval to realize the temperature protection of a thyristor and can not meet the field demand. The circuit is mainly characterized by comprising a high voltage-side detection circuit which is formed by the means that a temperature signal acquisition circuit, a voltage amplifier circuit, a voltage/frequency switching circuit and an optic fiber transmitting circuit are sequentially connected with one another, and a low voltage-side switching circuit which is formed by the means that an optic fiber receiving circuit and a frequency/voltage switching circuit are sequentially connected with each other; and the optic fiber transmitting circuit in the high voltage-side detection circuit is connected with the optic fiber receiving circuit of the low voltage-side switching circuit by an optic fiber. The detection circuit is higher in cost performance, a V/F (voltage/frequency) optic fiber transmission system of the detection circuit has the characteristics of being long in distance, anti-jamming, high in linear precision, good in performance and the like, and the detection circuit is mainly used for the on-line temperature of the thyristor in high-voltage starter starting equipment.

Description

technical field [0001] The invention belongs to the technical field of high-voltage motor starting. In particular, it relates to a thyristor online temperature detection circuit suitable for high-voltage motor starting equipment. Background technique [0002] At present, the core components of high-voltage solid-state soft starters at home and abroad are commonly used thyristors. Reducing the damage probability of thyristors is an important way to improve the reliability of high-voltage solid-state soft starters. There are three PN junctions inside the thyristor. When it is working, due to the movement of carriers (electrons and holes), the PN junction will heat up and cause the temperature to rise. When the temperature of the PN junction reaches a certain temperature, because the P-type and N The change of the type semiconductor will make the barrier region of the PN junction disappear, that is, the thyristor will lose its normal function. For silicon material semiconduct...

AI Technical Summary

Problems solved by technology

During the starting process of the high-voltage motor, the starting current flows through the thyristor, which will inevitably increase the temperature of the PN junction of the thyristor. The existing temperature protection technology only sets the time interval between each start of the starter to realize the temperature protection of the thyristor, which cannot meet the requirements. On-site requirements, in order to prevent the temperature rise of the thyristor from exceeding the maximum allowable temperature value during multiple starts and ensure the reliability of the high-voltage solid-state soft starter, in order to achieve this, the temperature value of the thyristor in the high-voltage environment must be detected in a timely and accurate manner

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