Rectifier Relay Arc Prevention via Pre-Cutoff Control
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Solution Overview
Problem
Conventional rectifiers in electrical power facilities face security issues due to poor direct current breaking capacity, leading to potential arc fires when relays disconnect under current-carrying conditions.
Innovation Solution
A rectifier design incorporating a relay, controller, detection resistor, and detection circuit, where the detection resistor is connected in series with the relay's winding, and a detection point is set between the resistor and winding, allowing the controller to receive an alarm signal and stop driving signals before relay disconnection, preventing arc fires by ensuring the relay disconnects without carrying current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a relay is used in the rectifier to control power input, then the rectifier can be controlled to switch power, but the relay has poor direct current breaking capacity which may cause arc fires when disconnecting under current-carrying conditions
Solution Approach 1:
The detection circuit monitors the voltage at the detection point before the relay disconnects. When abnormal voltage is detected indicating impending disconnection, the controller stops the driving signal in advance, ensuring the relay disconnects when carrying no current, thereby preventing arc fires
Solution Approach 2:
The detection circuit provides real-time feedback about the voltage at the detection point to the controller. This feedback mechanism allows the controller to monitor the relay's state and take corrective action by stopping the driving signal when abnormal conditions are detected
2Productivity
If the relay disconnects while carrying current to stop power input, then the rectifier can be turned off, but arc fires may occur due to poor direct current breaking capacity
Solution Approach 1:
The system performs preliminary detection of abnormal voltage at the detection point before the relay actually disconnects. When abnormality is detected, the controller stops the driving signal in advance, ensuring current is zero before disconnection occurs, thereby eliminating arc fire hazard while maintaining power switching capability
Solution Approach 2:
The detection circuit and controller work together to apply preliminary anti-action by stopping the driving signal before the relay disconnects under current-carrying conditions. This preventive measure counteracts the potential harmful effect of arc fires before they can occur
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
This design enhances security by rapidly stopping the rectifier's driving signal upon detecting abnormal voltage, preventing arc fires and improving the rectifier's safety during faults.
Implementation Method 1
a detection point of the detection circuit is set between the detection resistor and the winding, and an output end of the detection circuit is connected to the controller; when a voltage detected at the detection point of the detection circuit is abnormal
Implementation Method 2
a winding in the relay is powered on, so that the power input end of the rectifier circuit is connected to an external power source
Data Source
AI summary
A rectifier and an electrical power facility in which the rectifier is disposed are provided that relate to the field of electromechanical technologies. The rectifier includes a rectifier circuit, a relay, and a controller. The rectifier further includes a detection resistor and a detection circuit, where the detection resistor is connected in series to a winding in the relay, a detection point of the detection circuit is set between the detection resistor and the winding, and an output end of the detection circuit is connected to the controller. When a voltage detected at the detection point of the detection circuit is abnormal, the detection circuit outputs an alarm signal to the controller, and after receiving the alarm signal, the controller stops outputting a driving signal to the driving end of the rectifier circuit.