Power Semiconductor Control Device for Current Distribution Balance

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Solution Overview

Problem

Existing power semiconductor components with multiple parallel connections face challenges in evenly distributing electrical current, leading to potential overload and unreliable operation, as existing methods for balancing and controlling voltage and current are either inefficient or require complex symmetric designs and thermal management.

Innovation Solution

A control device with a driver element and measuring unit that adjusts electrical voltages and their time profiles at the control terminals of power semiconductor components based on real-time current measurements, ensuring balanced current distribution and adaptive operation by dynamically adjusting voltage levels and switching times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple power semiconductor devices are connected in parallel to increase power output, then the power output is improved, but the current distribution becomes unbalanced leading to potential overload

Engineering Contradiction:
Improvepower outputVSAvoidcurrent distribution balance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The control device continuously monitors the current through each power semiconductor device and dynamically adjusts the gate voltage of each device based on the measured current values. This feedback mechanism ensures that current is evenly distributed among parallel-connected devices, preventing overload and improving reliability while maintaining high power output capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control device dynamically adjusts the gate voltage of each power semiconductor device during operation based on real-time current measurements. This dynamic control allows the system to adapt to changing operating conditions and maintain balanced current distribution, resolving the contradiction between high power output and reliable operation.

Inventive Principle:
Principle #15Dynamics

2Reliability

If derating is applied to parallel-connected power semiconductor devices to ensure safety, then reliability is improved, but the power output capability is reduced

Engineering Contradiction:
Improveoperational safetyVSAvoidpower output capability
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

By implementing real-time current monitoring and feedback control, the system can operate parallel-connected devices at their full capacity without derating. The feedback mechanism ensures that current distribution remains balanced, allowing the system to achieve both high power output and reliable operation simultaneously, eliminating the need for conservative derating.

Inventive Principle:
Principle #23Feedback

3Reliability

If complex symmetric design is implemented for control device and connecting leads to achieve current balance, then current distribution symmetry is improved, but device complexity increases

Engineering Contradiction:
Improvecurrent distribution symmetryVSAvoidcontrol device and connecting leads design
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of requiring complex symmetric physical design, the invention uses feedback control to achieve current balance. The control device measures actual current through each device and adjusts gate voltages accordingly, simplifying the physical design while maintaining current distribution symmetry through active control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control device changes the gate voltage parameter of each power semiconductor device based on measured current values. This parameter adjustment compensates for asymmetries in the physical design, achieving current balance without requiring perfectly symmetric connecting leads and control circuits.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If time offset is introduced between switching pulses of parallel-connected devices to balance current, then current distribution is improved, but control complexity increases

Engineering Contradiction:
Improvecurrent distributionVSAvoidswitching control
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device uses feedback from current measurements to determine the optimal switching timing for each device. Instead of using fixed time offsets, the system dynamically adjusts switching pulses based on real-time current values, simplifying control logic while achieving balanced current distribution.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3563481B1Control device for controlling a power semiconductor component and method for controlling said power semiconductor component
Publication Date: 2020.11.18 SIEMENS AG
  • EP3563481B1 patent drawingFigure 1
  • EP3563481B1 patent drawingFigure 2~3
  • EP3563481B1 patent drawingFigure 4~5

AI summary

The invention relates to a control device (2) for controlling a power semiconductor component (1), wherein the power semiconductor component (1) has at least two voltage-controlled power semiconductor devices (V1, V2) which are electrically connected in parallel and each have a control connection (3), wherein the control device (2) comprises at least one driver element (GU, GU1, GU2) which can be used to set respective electrical voltages (UG1, UG2) at the control connections (3) of the power semiconductor devices (V1, V2), wherein the control device (2) has a measuring unit (5) which is designed to capture respective electrical currents (IV1, IV2) which flow through the power semiconductor devices (V1, V2), and wherein the at least one driver element is designed to set a level and/or a temporal profile of the respective electrical voltages (UG1, UG2) on the basis of the respective electrical currents (IV1, IV2).