Monolithic HVIC for Three-Level Inverter Control

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Solution Overview

Problem

Current control circuits for three-level inverters require galvanic isolation and are not efficiently integrated, leading to increased complexity and component count, and are not designed to handle negative reference potential changes effectively, which can result in latch-up and circuit failure during high-power switching.

Innovation Solution

A monolithically integrated drive circuit using SOI technology with level shifters that provide bidirectional signal transmission and are designed to handle both positive and negative reference potential changes, allowing for reliable operation in high-power systems by integrating control logic and driver stages within a single HVIC.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If galvanic isolation is implemented using discrete components on PCB, then potential separation between primary and secondary sides is achieved, but device complexity and component count increase

Engineering Contradiction:
Improvegalvanic isolationVSAvoidcomponent count
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the galvanic isolation function with the level shifter function into a single integrated circuit component. The potential isolator is combined with control logic and driver stages on the primary side, and with switch control circuits on the secondary side, eliminating the need for separate discrete isolation components on the PCB.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated circuit performs multiple functions simultaneously: galvanic isolation, signal level shifting, control logic processing, and driver stage control. This multi-functional approach replaces what would traditionally require multiple separate components.

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

2Reliability

If traditional level shifters are used for signal transmission, then signal transmission between different potentials is achieved, but the circuit cannot handle negative reference potential changes effectively

Engineering Contradiction:
Improvesignal transmissionVSAvoidreference potential handling
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The level shifter is designed with dynamic reference potential handling capability, allowing it to adapt to both positive and negative potential changes. The circuit can track and respond to varying reference potentials on the secondary side, including negative excursions, making it suitable for high-power switching applications where reference potentials fluctuate.

Inventive Principle:
Principle #15Dynamics

3Power

If control circuits are designed for high-power switching, then power handling capability is improved, but susceptibility to latch-up and circuit failure increases

Engineering Contradiction:
Improvepower handling capabilityVSAvoidlatch-up resistance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent implements protective measures against latch-up before it can occur. The integrated circuit includes built-in protection mechanisms that prevent latch-up conditions from developing, even during high-power switching operations with negative reference potential changes. This proactive protection ensures reliable operation in high-power applications.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The solution enables a compact, reliable, and efficient control circuit for three-level inverters that can handle high-power switching without latch-up, reducing component count and increasing reliability by using SOI technology for bidirectional signal transmission across varying reference potentials.

Implementation Method 1

The SOI (Silicon on Insulator) technologies and on the other hand pnisolated technologies (Junction Isolation). The SOI technology offers a dielectric potential separation of components or groups of components

Methodology Applied
Scientific EffectDielectric isolation: Dielectric

Data Source

PatentEP2871766B1Control circuit for three level inverter
Publication Date: 2017.08.16 SEMIKRON DANFOSS ELEKTRONIK GMBH & CO KG
  • EP2871766B1 patent drawingFigure 1~2
  • EP2871766B1 patent drawingFigure 3~4
  • EP2871766B1 patent drawingFigure 5~6

AI summary

A control circuit (32, 70) is designed with a primary-side circuit section (4) with a control logic (42) and a primary-side reference potential (420) and four secondary-side circuit sections (6), each with a driver stage (61, 62, 63, 64), for controlling a phase of a three-level inverter (10) with a first to fourth semiconductor switch (T1, T2, T3, T4), wherein each semiconductor switch and the associated secondary-side circuit section has an associated first to fourth secondary-side reference potential (610, 620, 630, 640), and wherein a level shifter (81, 82, 83, 84) connects the primary-side circuit section with the respective secondary-side circuit section and is thus associated with both circuit sections. In this case, the primary-side reference potential corresponds to the first secondary-side reference potential.Furthermore, at least the control logic of the first and second level shifters as well as the first and second driver stages are monolithically integrated in one HVIC.