DC-DC Converter Current Imbalance Detection via Segmented Sensing
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Solution Overview
Problem
Power supply systems using DC-DC voltage converters cannot effectively determine unbalanced current conditions between switching banks, especially when an over-current condition in one bank is not detectable.
Innovation Solution
A power supply system with multiphase switching banks and a detection system that uses current sensing resistors and a detection circuit to determine unbalanced current and over-current conditions by calculating average voltages across resistors in each switching bank, allowing for diagnostic outputs indicating these conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional current sensing methods are used in DC-DC voltage converters, then the system structure remains simple, but the ability to detect unbalanced current conditions and over-current states deteriorates
Solution Approach 1:
The detection system is segmented into multiple independent current sensing resistors (one per switching bank) with individual detection circuits for each bank. This segmentation allows independent monitoring of each switching bank's current conditions, enabling precise detection of unbalanced current states and over-current conditions without requiring a single complex centralized detection system.
Solution Approach 2:
Current sensing resistors are introduced as intermediary elements between the switching banks and the detection circuits. These resistors convert current information into voltage signals that can be processed by the detection circuits, enabling indirect but accurate measurement of current conditions without directly interfering with the power switching operations.
2Reliability
If multiple current sensing resistors are deployed in each switching bank, then the detection capability for unbalanced current and over-current conditions improves, but the system cost and component quantity increase
Solution Approach 1:
Instead of using multiple sensing resistors within each switching bank, the system uses one sensing resistor per switching bank (segmenting the sensing function by bank rather than by individual switches). This reduces the total number of sensing components while maintaining the ability to detect unbalanced current conditions between banks and over-current conditions within each bank.
Solution Approach 2:
Each current sensing resistor serves multiple functions: it detects over-current conditions within its own switching bank, contributes to detecting unbalanced current conditions between banks when combined with other bank measurements, and provides voltage signals for both individual bank monitoring and system-wide balance monitoring.
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
Enables the detection of unbalanced current and over-current conditions in DC-DC voltage converters, even when an over-current condition in one bank is not detectable, ensuring system stability and performance.
Implementation Method 1
The first switching bank has first and second switches that are selectively electrically coupled in series with a first resistor. The detection circuit receiving a first voltage across the first resistor.
Data Source
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AI summary
A power supply system having a detection system for determining an unbalanced current condition and an over-current condition in a DC-DC voltage converter is provided. The detection system has a detection circuit that outputs a first diagnostic voltage indicating an unbalanced current condition between first and second switching banks in the DC-DC voltage converter based on a first voltage and an average voltage, or an over-current condition in the first switching bank based on the first voltage. The detection circuit outputs a second diagnostic voltage indicating the unbalanced current condition between the first and second switching banks in the DC-DC voltage converter based on a second voltage and the average voltage, or an over-current condition in the second switching bank based on the second voltage.