Bidirectional Voltage Converter Switching Control
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Solution Overview
Problem
Bidirectional voltage converters with H-bridges in the automobile sector face high power losses due to inefficient switching operations, which are not adequately addressed by existing technologies.
Innovation Solution
A method for operating bidirectional voltage converters that involves measuring the actual mean bridge current and using this information to determine switch-on time points and durations for transistor switches, ensuring zero voltage switching and minimizing switching losses by adjusting switch-on times based on instantaneous and mean bridge current values, as well as input and output voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional switching operations are used in bidirectional voltage converters, then the converter can operate bidirectionally, but power losses are high due to inefficient switching
Solution Approach 1:
The patent applies dynamics by continuously adjusting the switch-on time points and durations of transistor switches based on real-time measurement of actual mean bridge current values. The switching parameters are dynamically adapted to the instantaneous operating conditions (current magnitude, direction, and voltage levels) to achieve zero voltage switching and minimize power losses across all operating modes.
Solution Approach 2:
The patent implements feedback by measuring the actual mean bridge current value during operation and using this information to determine optimal switch-on time points and durations for subsequent switching cycles. This closed-loop control ensures that switching operations are continuously optimized based on actual operating conditions, achieving zero voltage switching and reduced power losses.
2Loss of energy
If switch-on time points and durations are adjusted based on actual mean bridge current values, then zero voltage switching is achieved and power losses are reduced, but the control complexity increases
Solution Approach 1:
The patent applies self-service by using the bridge current measurement system (which already exists for other control functions) to provide the information needed for optimizing switch-on time points. The same current sensors and control infrastructure that monitor bridge current for basic operation are leveraged to calculate and implement zero voltage switching timing, avoiding additional complex measurement systems.
Solution Approach 2:
The patent implements universality by making the bridge current measurement serve multiple functions: it controls the basic bidirectional operation of the voltage converter and simultaneously provides the data needed for calculating optimal switch-on time points to achieve zero voltage switching. This multi-functional use of existing measurements reduces the need for additional complex control infrastructure.
3Productivity
If instantaneous bridge current values are measured and used for control, then switching losses are minimized, but the measurement and calculation requirements increase
Solution Approach 1:
The patent applies partial action by calculating the actual mean bridge current value using only the necessary portion of the instantaneous current information. Rather than requiring complete waveforms or excessive measurement precision across the entire switching cycle, the system calculates the mean value over the relevant period, which is sufficient to determine optimal switch-on time points without demanding ultra-precise instantaneous measurements.
Data Source
AI summary
Various embodiments include a method for operating a bidirectional voltage converter with an input-side half-bridge, an output-side half-bridge, and a bridge branch having a bridge inductance, comprising: determining an actual mean bridge current value flowing through the bridge branch during a respective subsequent switching cycle T1 of the transistor switches in a respective current switching cycle T0; determining switch-on time points and switch-on durations of the respective transistor switches for the respective subsequent switching cycle T1; and switching on the respective transistor switches at the respective ascertained switch-on time points and for the respective ascertained switch-on durations in the respective subsequent switching cycle T1.