Semiconductor Circuit Breaker Control for Lower Switching Losses

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing semiconductor power switch technologies experience high switching losses due to abrupt transitions between conducting and blocking states, leading to induced voltages that can damage components and result in inefficient energy usage.

Innovation Solution

A circuit arrangement that generates a control voltage with a specified time profile to manage the switching process of semiconductor power switches, taking into account operating variables like voltage and current slopes, and temperature, to prevent excessive induction voltages and reduce switching losses by adapting switching behavior based on real-time parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If semiconductor power switches are switched abruptly between conducting and blocking states, then switching speed is improved, but switching losses increase and induced voltages damage components

Engineering Contradiction:
Improveswitching speedVSAvoidswitching losses
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the switching behavior adaptive rather than fixed. The control device dynamically adjusts the switching parameters (such as gate voltage profiles, switching timing, and current slopes) based on real-time operating conditions including temperature, load current, and voltage levels. This allows the system to optimize switching speed while minimizing losses and preventing overvoltages under different operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying switching parameters such as gate voltage magnitude, gate resistance, switching timing, and current slopes based on operating conditions. The control device changes these parameters dynamically to achieve optimal switching performance, reducing switching losses and preventing component damage while maintaining adequate switching speed.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If semiconductor power switches are switched abruptly between conducting and blocking states, then productivity is improved, but component reliability deteriorates due to induced voltages

Engineering Contradiction:
Improveswitching frequencyVSAvoidcomponent reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements feedback by using sensors to monitor operating parameters such as temperature, voltage, and current, and using this information to adjust switching parameters in real-time. The control device receives feedback about the actual operating conditions and modifies switching behavior accordingly, enabling high switching frequencies while preventing overvoltages and maintaining component reliability through continuous adaptation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts switching parameters based on real-time operating conditions monitored through feedback mechanisms. This allows the system to maintain high productivity through increased switching frequencies while simultaneously protecting components from damage by adapting switching behavior to current operating states, particularly regarding temperature and voltage levels.

Inventive Principle:
Principle #15Dynamics

3Loss of energy

If switching parameters are optimized for minimum losses, then energy efficiency is improved, but switching speed decreases

Engineering Contradiction:
Improveswitching lossesVSAvoidswitching speed
Core Design Contradiction:
Loss of energyVSSpeed

Solution Approach 1:

The patent resolves this contradiction through dynamic adaptation of switching parameters based on operating conditions. Under conditions where high switching speed is critical, the system uses parameters that prioritize speed with acceptable losses. Under conditions where efficiency is paramount, the system adjusts parameters to minimize losses. This dynamic approach allows the system to optimize for either speed or efficiency depending on the specific operating context rather than being constrained to a fixed compromise.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes switching parameters such as gate voltage profiles, switching timing, and current slopes based on operating conditions. When low losses are the priority, parameters are adjusted to achieve softer switching with reduced electromagnetic interference and lower losses. When high speed is needed, parameters are modified to enable faster transitions. This flexible parameter adjustment resolves the contradiction between speed and efficiency.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If fixed switching parameters are used, then device complexity is reduced, but adaptability to different operating conditions deteriorates

Engineering Contradiction:
Improvecontrol circuit complexityVSAvoidadaptability to operating conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements self-service by enabling the control device to automatically adjust switching parameters based on monitored operating conditions without requiring complex external control systems. The system monitors its own state (temperature, voltage, current) and autonomously modifies switching behavior to optimize performance and protect components, reducing the need for complex external control circuitry while maintaining high adaptability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from sensors monitoring operating conditions to automatically adjust switching parameters. This feedback mechanism enables the system to adapt to different operating conditions (temperature variations, load changes, voltage fluctuations) without requiring complex predetermined control logic, achieving high adaptability with moderate complexity through intelligent response to measured parameters.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2735098B1Circuit arrangement for switching a current, and method for operating a semiconductor circuit breaker
Publication Date: 2021.03.17 SIEMENS AG
  • EP2735098B1 patent drawingFigure 1
  • EP2735098B1 patent drawingFigure 2
  • EP2735098B1 patent drawingFigure 3

AI summary

When switching a current (Ic) by means of a semiconductor circuit breaker (44), provision can be made for a control voltage to be generated at the control input (50) of the semiconductor circuit breaker (44) by an actuation circuit (42) at switching flanks of a switching signal, said control voltage having a profile which is flattened in relation to the profile of the switching signal. One disadvantage of a solution of this kind is that the switching losses in the power semiconductor (44) are very high for the period during which the control voltage is reduced only slowly with a flattened profile. The object of the present invention is to reduce the switching losses in a semiconductor circuit breaker (44). In the case of the circuit arrangement according to the invention, a value can be predefined for a switching parameter of a control device (56) of the actuation circuit (42), it being possible for a switching behaviour of the actuation circuit (42) to be influenced by said switching parameter. In this case, a specific parameter value of the switching parameter can be varied during operation of the actuation circuit (42).