Thyristor circuit and thyristor protection method

Abstract

A thyristor circuit (100) comprises at least one branch comprising at least one thyristor (10, 20), a thyristor control circuit (50) and a current detector (60, 61). The current detector (60, 61) is configured to detect a current value representative of an electrical current flowing through the thyristor and to input the detected current value into the thyristor control circuit. The thyristor control circuit is configured to determine a fault condition in which the detected current value exceeds a predetermined current threshold based on a deteriorated blocking ability of the thyristor. Dependent on the determination result, the thyristor control circuit triggers the thyristor into a conductive state.

Description

technical field [0001] The invention relates to a thyristor circuit having at least one branch comprising at least one thyristor and a thyristor protection method for protecting a thyristor in at least one branch. Background technique [0002] In high voltage and high current applications, electronic devices often use thyristors as power electronic components. Upon receiving a trigger current at its gate, the thyristor begins conducting current in a path from its anode terminal through its semiconductor junction stack to its cathode terminal. In the literature, triggering is also called excitation or gating. Thyristors are non-conducting, or blocking, unless triggered. [0003] Therefore, thyristors are used for current control in various applications, for example, as crowbars, high power rectifiers, etc. When thyristors or stacks of multiple series thyristors are connected in anti-parallel, they can be used to control current flow in both directions, eg in AC application...

AI Technical Summary

Problems solved by technology

As the temperature of the junction, or junction temperature, rises to high values, the blocking ability of the thyristor begins to deteriorate, resulting in a high resistance circuit through the junction

Therefore, in the case of blocking state and fault current conditions, an increase in junction temperature may also be promoted, which may lead to failure or thermal destruction of the thyristor

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