Dual Power Contactor Interlock for Abnormal Supply Switching
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Solution Overview
Problem
Conventional dual power supply systems fail to switch power supply paths when exceptions other than power failure occur, such as overvoltage, undervoltage, phase loss, or frequency anomalies, leading to potential hazards and expanded exceptions.
Innovation Solution
A power supply system with an active power contactor, standby power contactor, auxiliary power contactor, control switch, and controller, which interlock to automatically switch to a normal power supply circuit upon detecting abnormalities, ensuring continuous power supply by connecting the control switch in series with the auxiliary contactor to affect power supply paths directly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dual power supply interlocking mechanism is used, then power supply switching can be implemented when main or standby power supply is powered down, but power supply switching cannot be implemented when other exceptions occur (overvoltage, undervoltage, phase loss, frequency anomalies)
Solution Approach 1:
The control switch is designed to handle multiple types of exceptions universally. Instead of having separate switching mechanisms for power failure and other exceptions (overvoltage, undervoltage, phase loss, frequency anomalies), a single control switch integrates all exception detection and switching functions, making the system more versatile while maintaining reliability
2Ease of operation
If control switch is connected in series to auxiliary power contactor coil, then direct control of power supply path switching is achieved, but system complexity increases due to additional components and interlocking mechanisms
Solution Approach 1:
The patent merges the control functions for both power failure and other exceptions into a single control switch and auxiliary power contactor mechanism. By connecting the control switch in series with the auxiliary power contactor coil, the system combines multiple switching operations into one unified control path, simplifying operation despite the added component
Solution Approach 2:
The auxiliary power contactor serves as an intermediary mechanism between the control switch and the main power contactors. It mediates the switching action by controlling the power supply to the coils of active and standby power contactors, providing a buffered control mechanism that simplifies the overall control logic
Data Source
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AI summary
A power supply system and a control method are provided, where the power supply system includes: an active power contactor (1), a standby power contactor (2), an auxiliary power contactor (3), a control switch (4), and a controller (7). The active power contactor (1) is connected in series in a path of a main power supply circuit, and the standby power contactor (2) is connected in series in a path of a standby power supply circuit. The active power contactor (1) and the standby power contactor (2) are interlocked through the auxiliary power contactor (3). The auxiliary power contactor (3) and the control switch (4) are connected in series. The controller (7) is configured to: when the main power supply circuit is abnormal, control the control switch (4) to change a status of the auxiliary power contactor (3), to switch to the standby power supply circuit; or when the standby power supply circuit is abnormal, control the control switch (4) to change the status of the auxiliary power contactor (3), to switch to the main power supply circuit. According to the power supply system and the control method, when various exceptions occur in the power supply system, switching of the power supply path can be implemented, so as to provide more comprehensive protection for the power supply system, and avoid more serious faults caused by the exceptions.