Method for testing small current of thyristors and pulse trigger loops thereof

Abstract

The invention discloses a method for testing small current of thyristors and pulse trigger loops thereof. According to the method, a small current test loop is built through applying a test AC power supply outside an AK electrode of a tested thyristor and connecting a current-limiting resistor in series. When the test AC power supply applied to the AK electrode of the thyristor achieves a forwardvoltage peak, a pulse trigger loop of a static variable-frequency starting system valve control device conducts the tested thyristor, so that the tested thyristor is theoretically conducted for 1/4 ofa period; and through detecting the conduction time of the tested thyristor, judgment can be carried out to determine whether the tested thyristor and the pulse trigger loop thereof work normally ornot. The method is capable of correctly positioning abnormal thyristor element positions.

Description

technical field [0001] The invention relates to a thyristor and a small current testing method of a pulse trigger circuit thereof, belonging to the technical field of synchronous motor performance testing. Background technique [0002] The static variable frequency starting system is the best way to start large synchronous motors, and is widely used in gas turbines, condensers, pumped storage units and large pumping stations. At present, the capacity range of mainstream static frequency converters ranges from 2MW to 30MW. [0003] The thyristor is the core component of the static variable frequency starting system, which is used in the three-phase fully-controlled rectifier bridge circuit or the three-phase fully-controlled inverter bridge circuit of the static variable frequency starting system. In applications with a higher voltage level, the thyristor valve group is usually connected in series to divide the voltage in order to achieve a higher output voltage. In a set o...

AI Technical Summary

Problems solved by technology

The abnormality of the thyristor and its pulse trigger circuit will directly lead to the failure of the motor to start

When the thyristor circuit or the pulse starting circuit fails, the traditional test method cannot directly determine the location of the fault point. To find out the fault point accurately, it is necessary to change the main wiring of the test circuit to test the thyristors one by one, and the work repetition efficiency is low.

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