Bi-directional Current Detection in Power Supply Devices
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Solution Overview
Problem
Conventional current detection devices struggle to accurately detect currents flowing in both directions in bi-directional circuits, leading to inadequate protection and heat management.
Innovation Solution
A power supply device with a current detection system that includes a current sensor and controller, capable of distinguishing between positive and negative current directions by outputting different detection voltages, allowing for accurate calculation and management of conduction currents and heat quantities in bi-directional circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional current detection device is used in a bi-directional circuit, then the device structure is simple, but the device cannot accurately detect current flowing in the negative direction
Solution Approach 1:
The current detection system is segmented into two separate detection paths: one for positive direction current and one for negative direction current. Each path uses its own current sensor and detection circuit, allowing independent optimization of each detection channel while maintaining overall system accuracy for bi-directional current measurement.
Solution Approach 2:
The controller is designed with multi-functionality to handle both positive and negative direction current detection. It integrates multiple detection voltage outputs from different current sensors and universally processes both current directions through a unified control algorithm, enabling a single device to perform multiple detection functions.
2Reliability
If a single power supply unit is used, then the device complexity is reduced, but the heat quantity calculation becomes inconsistent for bi-directional circuits
Solution Approach 1:
The power supply system is segmented into two separate power supply units, with each unit dedicated to supporting current flow in one direction. This segmentation ensures that each power supply unit can independently and consistently calculate heat quantity for its designated current direction, eliminating calculation inconsistencies in bi-directional circuits.
Solution Approach 2:
Each power supply unit is configured with local quality optimized for its specific current direction. The first power supply unit is optimized for positive direction current with corresponding detection and calculation parameters, while the second power supply unit is optimized for negative direction current, ensuring consistent and accurate heat quantity calculation for each direction's specific characteristics.
Data Source
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AI summary
A current detection device (30) includes a current sensor (31) and a control unit (32). The current sensor (31) outputs a detection voltage according to a conduction current flowing through a bi-directional circuit (E) in which current is capable of flowing in a positive direction (P1) and a negative direction (P2) that is a direction opposite to the positive direction (P1). The control unit (32) calculates the conduction current based on the detection voltage output from the current sensor (31). For example, the control unit (32) calculates the conduction current based on an absolute value of a difference between a reference voltage that is the detection voltage output during a non-conductive state in which current is not flowing through the bi-directional circuit (E), and the detection voltage output during a conductive state in which current is flowing through the bi-directional circuit (E).