US 4,785,388 A · Gate pulse generator for thyristor converter

Abstract

In a gate pulse generator for a thyristor converter of the type in which in order to fire thyristors of the thyristor converter in which each arm is comprised of a plurality of series-connected thyristors, the gate pulses are generated in response to the gate command signal and the thyristor forward voltage signal and are converted into the light signals which in turn are transmitted to the thyristor converter, whether or not the forward voltage signal exists when the gate command signal is generated is detected and when the forward voltage signal is generated prior to the generation of the gate command signal, the pulse duration is narrowed to a minimum required for firing the thyristor. When the forward voltage signal is generated during the time interval in which the gate command signal continues, the differences in time point when the forward voltage signals are generated among the thyristors due to the storage carrier differences therebetween are taken into consideration so that the pulse duration is increased. Therefore, from the standpoint of the frequency of occurrence, the thyristors can be fired in response to the pulse signal with a narrow pulse duration in almost all cases.

Claims18

Dependent claims

A gate pulse generator for a thyristor converter in which in order to fire thyristors of the thyristor converter in which each unit arm is composed of a plurality of series-connected thyristors, a gate pulse signal is generated in response to a gate command signal and a thyristor forward voltage signal and is converted into a light signal which in turn is transmitted to the thyristor converter, said gate pulse generator comprising:

first pulse generator means for generating a gate pulse signal with a relatively narrow pulse duration;
second pulse generator means for generating a gate pulse with a relatively wide pulse duration;
and
logic circuit means for delivering a gate pulse with a relatively narrow pulse duration from said first pulse generator means when the gate command signal is received after the thyristor forward voltage signal has been already generated and delivering a gate pulse signal with a relatively wide pulse duration from said second pulse generator means when the gate command signal has been already generated or when the gate command signal is generated simultaneously with the generation of the thyristor forward voltage signal.

1 more element

first pulse generator means for generating a gate pulse signal with a relatively narrow pulse duration;
second pulse generator means for generating a gate pulse signal with a relatively wide pulse duration;
a first AND gate for carrying out the logic AND operation of forward voltage signals from respective thyristors constituting a unit arm, thereby delivering a forward voltage AND signal;
and
logic circuit means for delivering a gate pulse signal with a relatively narrow pulse duration from said first pulse generator means when it receives a gate command signal after the forward AND signal has been already generated by said first AND gate and also delivering a gate pulse signal with a relatively wide pulse duration from said second pulse generator means when a gate command signal has been already generated or when the gate command signal is generated simultaneously with the generation of the forward voltage signal by said first AND gate.

2 more elements

first pulse generator means for generating a gate pulse signal with a relatively narrow pulse duration;
second pulse generator means for generating a gate pulse signal for generating a gate pulse with a relatively wide pulse duration;
third pulse generator means for generating a gate pulse with a pulse duration which is between said pulse signal with a relatively narrow pulse duration and said pulse signal with a relatively wide pulse duration;
and
logic circuit means for delivering a gate pulse signal with a relatively narrow pulse duration from said first pulse generator means when the gate command signal is received after the thyristor forward voltage signal has been already generated, delivering a gate pulse signal with an intermediate pulse duration from said third pulse generator means when it receives the thyristor forward voltage signal after the gate command signal has been already generated and delivering a gate pulse with a relatively wide pulse duration from said second gate pulse generator means in the case of the forced firing at an insufficient margin angle.

2 more elements

Dependencies are inferred from the claim text.

Gate pulse generator for thyristor converter

Life of this patent

Gate pulse generator for thyristor converter

Life of this patent

Abstract

Claims18