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Thyristor with Reverse Recovery

Purpose

Behavioral model of a thyristor (SCR) with reverse recovery.

Library

Electrical / Power Semiconductors

Description

pict

This component is a behavioral model of a thyristor which reproduces the effect of reverse recovery. The effect can be observed when a forward biased thyristor is rapidly turned off. It takes some time until the excess charge stored in the thyristor during conduction is removed. During this time the thyristor represents a short circuit instead of an open circuit, and a negative current can flow through the thyristor. The thyristor finally turns off when the charge is swept out by the reverse current and lost by internal recombination. The same effect is modeled in the Diode with Reverse Recovery and described there in detail.

Parameters

Forward voltage
Additional dc voltage Vf    in volts (V) between anode and cathode when the thyristor is conducting. The default is 0.
On-resistance
The resistance Ron   of the conducting device, in ohms (_O_  ). The default is 0.
Off-resistance
The resistance Roff    of the blocking device, in ohms (_O_  ). The default is inf. If thyristors are connected in series (e.g. in a rectifier leg), the off-resistance must have a large finite value.
Continuous forward current
The continuous forward current If0    under test conditions.
Current slope at turn-off
The turn-off current slope dIr∕dt    under test conditions.
Reverse recovery time
The turn-off time trr   under test conditions.
Peak recovery current
The absolute peak value of the reverse current Irrm   under test conditions.
Reverse recovery charge
The reverse recovery charge Qrr   under test conditions. If both trr   and Irrm   are specified, this parameter is ignored.
Lrr
This inductance acts as a probe measuring the di∕dt  . It should be set to a very small value. The default is 10e-10.

Probe Signals

Thyristor voltage
The voltage measured between anode and cathode.
Thyristor current
The current through the thyristor flowing from anode to cathode.
Thyristor conductivity
Conduction state of the internal switch. The signal outputs 0 when the thyristor is blocking, and 1 when it is conducting.

References

A. Courtay, "MAST power diode and thyristor models including automatic parameter extraction", SABER User Group Meeting Brighton, UK, Sept. 1995.