Relay Actuation Duration Detection via Coil Current Minimum
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Solution Overview
Problem
Existing systems for determining the actuation duration of relays, such as electromechanical relays, are complex and costly, leading to decreased reliability and increased operational costs, particularly when handling high voltages and varying load types.
Innovation Solution
A system comprising a relay, a current-sensing device, and a controller that measures current through the actuation coil to determine the actuation duration by identifying a local minimum current value, allowing for precise timing adjustments to minimize inrush current and extend relay lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex detection circuitry rated for high voltages is used to detect relay contact position, then the detection reliability is improved, but the overall cost increases and the product reliability decreases
Solution Approach 1:
The patent introduces an intermediary current-sensing device that measures current through the actuation coil to indirectly detect relay contact position and actuation duration. This mediator approach avoids direct high-voltage contact detection, reducing complexity while maintaining reliability through current-based sensing that reflects the mechanical state of the relay.
Solution Approach 2:
The patent replaces complex high-voltage electrical detection circuitry with a simpler current-sensing system that monitors electromagnetic coil current. This substitution uses electrical measurement of the actuation process itself rather than direct mechanical or high-voltage contact sensing, simplifying the detection system while providing accurate actuation duration measurement.
2Duration of action of stationary object
If relay actuation timing is precisely controlled to minimize inrush current, then the relay operational lifespan is extended, but the timing configuration complexity increases
Solution Approach 1:
The patent implements feedback by continuously monitoring the actuation coil current and using this information to determine actual actuation duration. The controller measures current values over time, identifies the local minimum indicating contact closure, and uses this feedback to precisely control timing for zero-crossing synchronization, thereby minimizing inrush current and extending relay lifespan without complex manual configuration.
Solution Approach 2:
The system performs self-service by automatically measuring its own actuation duration through current sensing and using this self-acquired information to optimize subsequent actuation timing. The controller independently determines the local minimum current point and adjusts timing accordingly, eliminating the need for external complex timing configuration while achieving precise inrush current minimization.
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
The solution simplifies the detection of actuation duration, reduces complexity and cost, and enhances reliability by allowing for optimized timing that minimizes inrush current, thereby extending the operational lifespan of relays across various load types.
Implementation Method 1
The controller can be further configured to receive from the current-sensing device a plurality of measurement values for the current through the actuation coil
Implementation Method 2
The relay can include an actuation coil, an armature, and at least two contacts
Data Source
AI summary
An example system for determining the actuation duration of a relay can include a relay, a current-sensing device, and a controller. The relay can have an actuation coil, and armature, and a first and second contact. The current-sensing device can measure a current through the actuation coil. The controller can actuate the relay. The controller can also receive from the current-sensing device a plurality of measurement values for the current through the actuation coil. The controller can determine an actuation duration based on a local minimum value for the plurality of measurement values. The actuation duration can correspond to a duration of a movement of an armature of the relay from the first contact of the relay to the second contact of the relay. An actuation delay of the relay can be calculated based on the zero-crossing time of an input voltage value and the actuation duration.