Bridge-Arm Power Converter Startup Fault Detection
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Solution Overview
Problem
Power converters face issues with switching transistor failures leading to short-circuit faults and overcurrent damage, necessitating safe startup self-tests to prevent further damage.
Innovation Solution
A power converter design with a controller that performs short-circuit fault detection on switching transistors by charging or discharging capacitors after startup, using a soft-start switch and resistor to limit voltage changes, and detecting faults based on voltage thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power converter is started without self-test, then the startup time is reduced, but switching transistor short-circuit faults may cause busbar short-circuit or overcurrent damage
Solution Approach 1:
The patent performs preliminary self-test actions before the power converter enters normal operation. The controller activates switching transistors in sequence, charges capacitors through specific paths, and detects voltage levels to identify potential short-circuit faults before they can cause damage during actual operation.
Solution Approach 2:
The patent applies preliminary anti-action by detecting and preventing potential faults before they manifest as harmful effects. The self-test procedure identifies switching transistor short-circuits early, preventing them from causing busbar short-circuits or overcurrent damage during normal operation.
2Measurement precision
If the capacitor charging voltage threshold is set high, then the detection accuracy is improved, but the voltage change rate during charging increases
Solution Approach 1:
The patent dynamically adjusts the charging process by monitoring both the voltage level and voltage change rate. The controller modifies the charging behavior based on real-time conditions, balancing the need for accurate threshold detection with the constraint of limiting voltage change rates to protect the system.
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
Prevents abnormal conditions like busbar short-circuits and improves reliability by accurately detecting switching transistor faults before normal operation, ensuring safe startup.
Implementation Method 1
A target capacitor starts to be charged after the target switching transistor in each bridge arm is turned on
Data Source
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AI summary
Embodiments of this application provide a power converter. The power converter includes a controller, at least one bridge arm, and a first capacitor and a second capacitor that are connected in series. Each bridge arm includes a first switching transistor, a second switching transistor, a third switching transistor, and a fourth switching transistor. The first switching transistor and the fourth switching transistor are connected in series and then connected in parallel to two ends of the first capacitor and the second capacitor that are connected in series, and a connection end of the first switching transistor and the fourth switching transistor is connected to a connection end of the first capacitor and the second capacitor through the second switching transistor and the third switching transistor that are connected in reverse series. After the power converter is started, the controller controls a target switching transistor in each bridge arm to remain on. A target capacitor starts to be charged after the target switching transistor in each bridge arm is turned on. The target capacitor is at least one of the first capacitor and the second capacitor, and the target switching transistor is at least one of the switching transistors in each bridge arm. After the target capacitor is charged, and when a voltage across two ends of the target capacitor does not reach a voltage threshold, the controller outputs information indicating that a switching transistor short-circuit fault exists in each bridge arm.