Converter Sub-Module Control Circuit Energy Management

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Solution Overview

Problem

Conventional control methods for converter arrangements fail to prevent overloading and potential failure of control circuits, particularly in scenarios involving undervoltage faults, leading to inefficient energy management and potential system crashes.

Innovation Solution

Implementing a control method that limits switching operations in sub-modules by managing a control variable, which increases with each switch on/off cycle based on energy consumption and reduces between cycles, blocking further operations when the variable exceeds a predetermined threshold to ensure the control circuit is not overloaded, and only releasing when the variable falls below the threshold with hysteresis consideration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If switching operations are increased to improve converter performance and response speed, then productivity and control precision are improved, but the control circuit becomes overloaded and reliability deteriorates

Engineering Contradiction:
Improveswitching operation frequencyVSAvoidcontrol circuit reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control circuit monitors its own energy storage status through the control variable and provides feedback to limit further switching operations when the energy level becomes critical. This self-regulating feedback mechanism prevents overloading while allowing maximum switching operations during normal operation, thus maintaining both productivity and reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control circuit dynamically adjusts its switching operation capacity based on real-time energy storage conditions. When energy is充足, the circuit operates at full switching capacity; when energy depletes toward the critical threshold, switching operations are automatically limited. This dynamic adaptation resolves the contradiction between maintaining high productivity and ensuring reliability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If switching operations are limited to prevent control circuit overloading, then reliability is improved, but productivity and converter performance deteriorate

Engineering Contradiction:
Improvecontrol circuit reliabilityVSAvoidconverter output
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control circuit performs preliminary energy management by continuously monitoring the control variable and preparing to limit switching operations before actual overloading occurs. This preventive approach ensures reliability is maintained while minimizing the impact on productivity, as switching operations are only limited when truly necessary to prevent circuit failure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control variable serves as a dynamic parameter that changes based on energy storage status. By monitoring changes in this parameter, the system automatically adjusts switching operation limits only when the control variable approaches the critical threshold, thereby maintaining high productivity during normal operation while ensuring reliability when energy becomes critical.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If energy storage is maintained at high levels to ensure reliable control circuit operation, then reliability is improved, but energy efficiency deteriorates due to excessive energy reservation

Engineering Contradiction:
Improvecontrol circuit reliabilityVSAvoidenergy efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The control circuit maintains continuous monitoring of the control variable and ensures uninterrupted energy supply to switching operations. By continuously managing energy storage and switching operations, the system maintains reliability without requiring excessive energy reserves, as the continuous action ensures energy is used efficiently and replenished only when necessary.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The control circuit serves itself by autonomously managing its own energy storage status through the control variable. It determines when energy replenishment is needed and limits switching operations only when absolutely necessary, eliminating the need for excessive energy reserves while maintaining reliability. This self-service approach optimizes energy efficiency by using energy only when required for actual switching operations.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3751714B1Method for controlling a converter assembly
Publication Date: 2023.04.26 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP3751714B1 patent drawingFigure 1
  • EP3751714B1 patent drawingFigure 2
  • EP3751714B1 patent drawing

AI summary

The invention relates, inter alia, to a method for controlling a converter arrangement (5) comprising at least one series circuit (11), wherein the at least one series circuit (11) has at least two series-connected sub-modules (12), each comprising at least two switches (S1, S2) and a capacitor (C), and wherein, in the method, controlling the converter arrangement (5) enables switching one or more of the sub-modules (12) and switching on or off at least one of the switches (S1, S2) of the sub-modules (12) to be switched. According to the invention, it is provided that, in at least one of the sub-modules (12), the switching operations are limited such that at least one control circuit (21) assigned to this sub-module (12) is not overloaded beyond a predetermined level.