Power Supply Device Bidirectional Current Blocking
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Solution Overview
Problem
Existing power supply devices fail to effectively block reverse currents when a short circuit occurs in one of the MOSFETs, leading to potential overcharge issues between DC power supply units.
Innovation Solution
A power supply device with switch units on each conductive path that can be controlled to block currents in both directions, using voltage and current detection units to manage states and prevent abnormal current flows between power supply units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a MOSFET is used in each DC power supply synthetic circuit to block reverse current, then the circuit can operate normally, but if a short circuit failure occurs in the MOSFET, reverse current cannot be blocked
Solution Approach 1:
The power supply system is divided into multiple independent power supply units, each with its own dedicated switch unit and control circuit. This segmentation ensures that a failure in one unit does not affect the reverse current blocking capability of other units, as each unit independently manages its own current flow and blocking operations.
Solution Approach 2:
A connection part is introduced as an intermediary between the first and second conductive paths. This connection part serves as a controlled interface that can be electrically connected or disconnected based on system state, providing an additional layer of control beyond the MOSFETs alone to prevent reverse current flow even when MOSFETs fail.
2Adaptability or versatility
If a reserve DC power supply is provided with a MOSFET on its path, then the reserve supply can be activated when needed, but if the MOSFET fails with short circuit, current cannot be blocked from flowing into the reserve supply
Solution Approach 1:
The switch units are designed to dynamically change their electrical state between connected and disconnected based on real-time detection of system conditions. This dynamic control allows the system to adapt to various operational states including normal operation, reserve activation, and failure conditions, maintaining reliable current blocking throughout.
Solution Approach 2:
Voltage detection units and current detection units provide continuous feedback to the control unit about the system state. Based on this feedback, the control unit adjusts the switching operations of the switch units to maintain proper current blocking, even when MOSFETs experience short circuit failures.
3Measurement precision
If voltage detection units and current detection units are added to detect abnormal states, then the system can identify failures, but the device complexity increases
Solution Approach 1:
The control unit performs multiple functions: it controls the switching operations of both switch units, processes signals from voltage detection units and current detection units, determines abnormal states, and manages the overall power supply logic. This multi-functionality reduces the need for separate dedicated control circuits for each function, thereby limiting the increase in device complexity.
4Reliability
If the first switch unit is controlled to block current in both directions during abnormal states, then reverse current is prevented, but the control logic becomes more complex
Solution Approach 1:
The control of the first switch unit and second switch unit is merged into a single control unit that manages both switches based on a unified set of detection signals. This unified control approach simplifies the overall control logic compared to having independent control circuits for each switch, as the control unit can coordinate their operations to achieve bidirectional current blocking through integrated decision-making.
Data Source
AI summary
The present invention realizes a power supply device that can, even if an abnormality occurs in a power supply unit, block a current from flowing into the path from the other power supply unit. A power supply device (1) includes: a first conductive path (31) that is a path for power between a first power supply unit (91) and a load (94); a second conductive path (32) that is connected to the first conductive path (31) and to a second power supply unit (92); a first switch unit (34) that is provided on the first conductive path (31) between a connection part (33), at which the first conductive path (31) is connected to the second conductive path (32), and the first power supply unit (91), and switches to an electrically disconnected state, in which the first switch unit (34) blocks a current from flowing in either direction, and to an electrically connected state, in which the first switch unit (34) allows a current to flow therethrough; a second switch unit (35) that is provided on the second conductive path (32) between the connection part (33) and the second power supply unit (92), and switches to an electrically disconnected state, in which the second switch unit (35) blocks a current from flowing in either direction, and to an electrically connected state, in which the second switch unit (35) allows a current to flow therethrough; and a control unit (39) that controls respective switching operations of the first switch unit (34) and the second switch unit (35).