Half-Bridge Converter PWM Phase Shift for Mode Transition Limits

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Solution Overview

Problem

Existing control methodologies for half-bridge converters face challenges in switching between complementary and non-complementary modes, risking violations of constraints such as dead-time and minimum pulse-width, which can limit the maximum voltage available across the load.

Innovation Solution

A processor device configures the control signals for the upper and lower switches of a half-bridge converter to switch between modes by determining a time-shift for the PWM signals, ensuring compliance with dead-time and minimum pulse-width constraints, and optionally setting the time-shift to zero if center-aligned PWM signals fulfill these constraints, thereby reducing processor workload and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If control methodology is changed between complementary and non-complementary modes, then adaptability to different output current situations is improved, but risk of violating bridge converter and load constraints increases

Engineering Contradiction:
Improveadaptability to different output current situationsVSAvoidrisk of violating constraints
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements dynamic switching between complementary and non-complementary control modes based on real-time operating conditions. The processor device monitors the desired output current and automatically selects the appropriate control methodology, allowing the system to adapt to different situations while maintaining constraint compliance through controlled transition timing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies preliminary action by introducing a time-shift parameter before actually switching between control modes. This time-shift prepares the control signals in advance to ensure that dead-time and minimum pulse-width constraints are satisfied during the transition, preventing constraint violations before they can occur.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If dead-time and minimum pulse-width constraints are enforced during mode switching, then reliability is improved, but maximum voltage available across load is reduced

Engineering Contradiction:
Improveconstraint complianceVSAvoidmaximum voltage across load
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent changes the timing parameter of control signals by introducing a time-shift that is dynamically adjusted based on the switching transition requirements. This parameter modification allows the system to maintain constraint compliance while minimizing the impact on voltage output, as the time-shift is optimized to be as small as possible while still ensuring reliable operation.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If processor continuously monitors and adjusts control signals to prevent constraint violations, then reliability is improved, but processor workload and power consumption increase

Engineering Contradiction:
Improveconstraint complianceVSAvoidprocessor power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements self-service by designing the control system to automatically detect when mode switching is required and to self-correct timing issues through the time-shift mechanism. The processor only intervenes when necessary to calculate and apply the time-shift, rather than continuously monitoring and adjusting all parameters, thereby reducing computational workload and power consumption while maintaining reliability.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4387064A1Bridge converter control
Publication Date: 2024.06.19 VOLVO TRUCK CORP
  • EP4387064A1 patent drawingFigure 1a~3b
  • EP4387064A1 patent drawingFigure 3c~4
  • EP4387064A1 patent drawingFigure 5a~6c

AI summary

A computer system comprising a processor device configured to switch between switching modes of a load (10) is presented. The switching modes are a complementary switching mode and a non-complementary switching mode of an upper switch (110) and a lower switch (120) of a first half-bridge converter (100) configured to provide a wanted power to a load (10). The processor device is configured to provide a first upper control signal (115) to the upper switch (110) and a first lower control signal (125) to the lower switch (120) as center aligned PWM-signals at a first PWM period. Responsive to determining that a current switching mode is to be changed at a second PWM period, the processor device is further configured to determine a time-shift for shifting the first upper control signal (115) and the first lower control signal (125), and to provide the first upper control signal (115) shifted by the time-shift to the upper switch (110) and the first lower control signal (125) shifted by the time-shift to the lower switch (120) at the second PWM period.