Inductive Gate Current Regulator for Thyristor Bridge Control

Solution Overview

Problem

Conventional methods for controlling thyristors in half-controlled network bridges face issues with high power consumption and electromagnetic disturbances due to resistor-based gate current generation, which is unreliable and complex, especially in half-controlled thyristor bridges.

Innovation Solution

A method using a common constant current regulator to provide a precise and inductive gate current independent of auxiliary voltage changes, with a single current source switched based on phase voltages, allowing for efficient thyristor control with fewer components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resistor-based gate current generation is used, then thyristors can be controlled, but power consumption increases and electromagnetic disturbances occur

Engineering Contradiction:

Improvethyristor control reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the fundamental parameter of gate current generation from resistive to inductive. By using an inductive component instead of a resistor, the system achieves thyristor control while minimizing power consumption and avoiding electromagnetic disturbances caused by rapid current switching.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the electrical resistance mechanism with an inductive mechanism. The inductive component provides current restriction through electromagnetic induction rather than resistive heating, thereby eliminating the power loss and electromagnetic interference associated with resistor-based current limiting.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If resistor-based gate current generation is used, then thyristors can be controlled, but electromagnetic disturbances increase

Engineering Contradiction:

Improvethyristor control reliabilityVSAvoidelectromagnetic disturbances

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the fundamental parameter of gate current generation from resistive to inductive. By using an inductive component instead of a resistor, the system achieves thyristor control while minimizing power consumption and avoiding electromagnetic disturbances caused by rapid current switching.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If continuous switching of gate current circuit is used, then thyristors can be controlled at high frequency, but electromagnetic disturbances increase

Engineering Contradiction:

Improveswitching frequencyVSAvoidelectromagnetic disturbances

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the fundamental parameter of gate current generation from resistive to inductive. By using an inductive component instead of a resistor, the system achieves thyristor control while minimizing power consumption and avoiding electromagnetic disturbances caused by rapid current switching.

Inventive Principle:

Principle #35Parameter changes

4Loss of energy

If gate current magnitude is restricted by resistor, then power consumption is reduced, but current may be insufficient for reliable thyristor turn-on

Engineering Contradiction:

Improvepower consumptionVSAvoidthyristor turn-on reliability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent changes the fundamental parameter of gate current generation from resistive to inductive. By using an inductive component instead of a resistor, the system achieves thyristor control while minimizing power consumption and avoiding electromagnetic disturbances caused by rapid current switching.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces power consumption and minimizes electromagnetic disturbances by ensuring consistent thyristor activation with reduced component complexity and improved reliability.

Implementation Method 1

The gate current is taken through an inductive component, thereby restricting the rate of current rise

Methodology Applied

Scientific EffectInductance: Inductor

Data Source

PatentUS7855900B2Method and arrangement in connection with half-controlled network bridge

Publication Date: 2010.12.21 ABB (SCHWEIZ) AG

AI summary

A method and an arrangement are provided for controlling phase-specific thyristors of a half-controlled network bridge. The method includes identifying continuously a thyristor to be controlled on the basis of magnitudes of supplying phase voltages, controlling the thyristor by enabling a current flow to its gate current circuit through an inductive component of a constant current regulator, which is common to all the gate current circuits. The thyristor control includes determining a magnitude of the gate current at the potential of the gate conductor in the constant current regulator, alternately switching off the voltage producing the gate current from the gate current circuit when the gate current is higher than a first predetermined limit, and switching on the voltage producing the gate current in the gate current circuit when the gate current is lower than a second predetermined limit.