Multi-Phase Buck Converter Fault Detection for Shorted MOSFET Phases
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Solution Overview
Problem
In multi-phase buck converter circuits, a short-circuited MOS transistor can cause the entire circuit to malfunction, leading to improper voltage supply to the load, resulting in either a short circuit or overvoltage, which can render the load non-functional.
Innovation Solution
A fault detection method is implemented where a detection controller synchronously monitors the voltage at each phase buck circuit's fault detection point, determining if any phase buck circuit is faulty and isolating it by stopping the drive circuit's operation, thereby preventing the load from being affected by faulty components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MOS transistors are used in phase buck circuits to reduce voltage ripple, then power supply efficiency is improved, but the circuit becomes vulnerable to short-circuit faults that can render the load non-functional
Solution Approach 1:
The patent implements preliminary fault detection by monitoring the voltage at the fault detection point before the short-circuit fault can damage the load. The detection controller continuously checks the voltage status, and when a fault is detected (voltage equals power supply voltage indicating lower MOS transistor short-circuit, or voltage equals zero indicating upper MOS transistor short-circuit), the system immediately isolates the faulty phase buck circuit by controlling the switch transistor to stop current flow, preventing the fault from affecting the load.
2Object-affected harmful factors
If fault detection is implemented to isolate faulty phase buck circuits, then load protection is improved, but device complexity increases due to additional detection and control components
Solution Approach 1:
The patent introduces a fault detection point as an intermediary monitoring location in the circuit. This detection point is strategically placed to provide voltage information that indicates the operational status of the MOS transistors. The detection controller uses this intermediate voltage signal to determine whether a short-circuit fault has occurred and to control the switch transistor accordingly, enabling fault isolation without requiring direct monitoring of each transistor's internal state.
3Measurement precision
If synchronous detection is performed on all phase buck circuits, then fault detection accuracy is improved, but detection time and processing load increase
Solution Approach 1:
The patent extracts only the critical voltage information from each phase buck circuit at the fault detection point, rather than performing comprehensive monitoring of all circuit parameters. The detection controller synchronously detects the voltage status at these extracted key points across all phases, determines fault conditions based on simple voltage threshold comparisons, and immediately isolates faulty circuits. This extraction approach maintains high detection accuracy while minimizing processing time and computational load.
Data Source
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AI summary
This application discloses a multi-phase buck converter circuit, a fault detection method and apparatus thereof, and a storage medium, and belongs to the field of electronic technologies. The multi-phase buck converter circuit includes a power supply, N-phase buck circuits, N inductors, a first capacitor, a load, a detection controller, and a drive circuit. An input terminal of the detection controller is connected to a fault detection point of each phase buck circuit in the N-phase buck circuits. Because the fault detection point of each phase buck circuit corresponds to different voltages at different time points, the detection controller may detect, based on the voltage at the fault detection point of each phase buck circuit in the N-phase buck circuits, whether each phase buck circuit is faulty. When the detection controller determines that any one of the phase buck circuits is faulty, the drive circuit may stop driving the any one of the phase buck circuits. This implements isolation of the any one of the phase buck circuits, and avoids a case in which the load cannot work normally because the any one of the phase buck circuits is faulty.