IGBT Driver Circuit Dynamic Offset Voltage Control

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Solution Overview

Problem

Conventional IGBT module driving systems face challenges in accurately controlling the detection level of protection voltage due to variable saturation voltage, which affects precise protection and reliability, especially under changing temperature and gating voltage conditions.

Innovation Solution

A circuit and system that includes a detection circuit with a variable resistance, controlled by a controller that adjusts resistance values based on temperature and gating voltage sensors to maintain accurate detection levels of protection voltage, ensuring precise protection of switching modules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a fixed offset voltage is used for detecting saturation voltage, then the protection circuit can operate with simple initial design, but the detection accuracy deteriorates when driving conditions change

Engineering Contradiction:
Improveinitial design simplicityVSAvoiddetection accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies the dynamics principle by replacing the fixed offset voltage with a dynamically adjustable offset voltage that changes according to driving conditions. The controller modifies the offset voltage based on temperature and gating voltage conditions, allowing the protection circuit to maintain accurate detection across varying operating conditions while preserving the simplicity of the initial design.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the offset voltage parameter according to temperature and gating voltage conditions. Instead of using a constant offset voltage, the system adjusts this parameter dynamically to compensate for changes in saturation voltage characteristics, thereby maintaining detection accuracy across different driving conditions.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the saturation voltage detection is performed with a fixed threshold, then the protection circuit operation is simple, but the protection precision deteriorates under varying temperature and gating voltage conditions

Engineering Contradiction:
Improveprotection circuit operation simplicityVSAvoidprotection precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent changes the detection threshold parameter dynamically based on temperature and gating voltage conditions. The controller adjusts the threshold according to the actual operating conditions, ensuring that the protection precision is maintained across varying temperatures and gating voltages while keeping the protection circuit operation relatively simple through automated adjustment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by continuously monitoring temperature and gating voltage conditions and using this information to adjust the detection threshold. The controller receives feedback about the operating conditions and modifies the threshold accordingly, creating a closed-loop system that maintains protection precision without requiring complex manual intervention.

Inventive Principle:
Principle #23Feedback

3Productivity

If the offset voltage is set at manufacturing, then the production process is efficient, but the adaptability to different driving conditions deteriorates

Engineering Contradiction:
Improveproduction efficiencyVSAvoidadaptability to driving conditions
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent makes the offset voltage dynamic and adjustable after manufacturing, allowing the system to adapt to different driving conditions. The controller can modify the offset voltage based on temperature and gating voltage conditions, providing adaptability without requiring complex manufacturing processes or multiple pre-configured versions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent creates a universal protection circuit that can operate effectively across various driving conditions through dynamic adjustment. By implementing a controller that adapts the offset voltage and threshold based on operating conditions, the same circuit design serves multiple operating scenarios, enhancing versatility without complicating the production process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 allows for precise and stable protection of switching modules by dynamically adjusting detection levels according to driving conditions, enhancing reliability and ensuring proper operation across a wide range of conditions.

Implementation Method 1

a PTC thermistor 120 having its resistance value changed according to a temperature change of the IGBT devices 112

Methodology Applied
Scientific EffectPositive temperature coefficient thermistor effect: Thermistor

Implementation Method 2

a saturation voltage Vce (Sat) between a collector and an emitter, which is proportional to a current generated when the IGBT is turned on, is used to sense a current increase into more than a predetermined value

Methodology Applied
Scientific EffectVoltage detection: Ohm's Law

Data Source

PatentEP3340464B1Circuit and system for driving switching modules
Publication Date: 2022.11.16 LG ELECTRONICS INC
  • EP3340464B1 patent drawingFigure 1~2
  • EP3340464B1 patent drawingFigure 3~5
  • EP3340464B1 patent drawingFigure 6

AI summary

Disclosed are a circuit and a system for driving switching modules. The driving circuit and system are capable of controlling a detection level of a protection voltage of a switching module, by controlling a voltage of a detection circuit for detecting the protection voltage, through a control of a variable resistance.