Switching Cell Dead Time Control via Current Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing switched-mode converters face inefficiencies in conversion and generate high levels of harmonics, particularly when handling AC voltages/currents, and have complex control methods for switches.
Innovation Solution
A method and device for controlling switches in switching cells by measuring current flow through switches, setting a switching dead time based on these measurements, and using a diode to conduct current when both switches are off, which includes a sensor, comparator circuit, and integrator to optimize dead time for improved efficiency and reduced harmonics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If switched-mode converters are used to deliver voltage and current from a power supply, then voltage and current conversion is achieved, but conversion efficiency is insufficient and harmonic levels are high
Solution Approach 1:
The patent applies dynamics by making the dead time variable rather than fixed. The control device dynamically adjusts the dead time duration based on real-time measurements of current through the first switch, allowing the system to adapt to changing operating conditions and optimize both efficiency and harmonic reduction across different load scenarios
Solution Approach 2:
The patent implements feedback by measuring the current through the first switch and using this measurement to adjust the dead time. The control device continuously monitors the current and modifies the dead time accordingly, creating a closed-loop control system that optimizes conversion efficiency and reduces harmonic generation
2Loss of energy
If dead time is set too short to improve efficiency, then conversion efficiency increases, but risk of simultaneous switch conduction increases causing harmful effects
Solution Approach 1:
The patent applies self-service by having the system automatically determine the appropriate dead time based on its own operating conditions. The control device measures the current through the first switch and autonomously adjusts the dead time without external intervention, ensuring optimal protection against simultaneous conduction while maintaining efficiency
Solution Approach 2:
The patent changes the dead time parameter dynamically based on measured current conditions. Rather than using a fixed conservative dead time, the system adjusts this parameter in real-time according to the actual current flow, allowing shorter dead times when safe and maintaining protection when needed
3Manufacturing precision
If complex control methods are used to manage switch timing, then switch control precision is improved, but device complexity increases
Solution Approach 1:
The patent applies self-service by having the control device automatically determine optimal dead time based on measured current conditions. The system self-adjusts without requiring complex external control circuits or manual tuning, simplifying the overall control architecture while maintaining precise switch timing
Solution Approach 2:
The patent simplifies control by changing from fixed parameter control to dynamic parameter adjustment. The dead time is automatically modified based on measured current, eliminating the need for complex control algorithms or multiple control circuits while achieving precise switch timing
Data Source
AI summary
A method of controlling first and second switches of a switching cell, including measuring a current flowing through the first switch when the first switch is controlled to the off state, and setting a switching dead time according to the measurement.