Connection Conductor RC Adaptation for EMI-Resistant Measurement Signals
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Solution Overview
Problem
Existing connection conductors used to transmit measurement signals between sensors and intelligent electronic devices (IEDs) are susceptible to external electromagnetic transient interference, which can distort measurement accuracy.
Innovation Solution
The connection conductor is adapted to a frequency range where interference occurs, specifically using terminating resistors and additional capacitance to form a capacitive voltage divider, making it insensitive to high-frequency interference fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional connection conductor is used to transmit measurement signals, then the conductor can transmit signals between sensor and IED, but the measurement accuracy deteriorates due to electromagnetic transient interference from circuit breaker switching
Solution Approach 1:
The patent applies the principle of converting harm into benefit by using the electromagnetic interference itself as a signal source. The adaptation circuit (comprising capacitor C1 and resistor R1) detects the transient interference caused by circuit breaker switching and converts it into a measurable voltage signal. This allows the system to not only compensate for the interference but also to utilize it for monitoring and diagnostic purposes, thereby improving measurement accuracy rather than merely protecting against the interference.
Solution Approach 2:
The patent implements parameter changes by modifying the electrical characteristics of the connection conductor through the adaptation circuit. The capacitor C1 and resistor R1 form an RC circuit with specific time constants that are tuned to match the frequency characteristics of the electromagnetic transient interference. By adjusting these passive components, the system adapts its frequency response to reject specific interference frequencies while maintaining signal transmission in the desired frequency range.
2Object-affected harmful factors
If the connection conductor is adapted to frequency range where interference occurs, then insensitivity to high-frequency interference is achieved, but device complexity increases due to additional components
Solution Approach 1:
The patent applies parameter changes by modifying the electrical characteristics of the connection conductor through the adaptation circuit. The capacitor C1 and resistor R1 form an RC circuit with specific time constants that are tuned to match the frequency characteristics of the electromagnetic transient interference. By adjusting these passive components, the system adapts its frequency response to reject specific interference frequencies while maintaining signal transmission in the desired frequency range.
Solution Approach 2:
The adaptation circuit acts as an intermediary between the sensor output and the IED input. Rather than directly connecting the sensor to the IED, the RC circuit is inserted as a intermediate stage that filters and conditions the signal. This intermediary structure allows the system to maintain simplicity at the sensor and IED ends while introducing complexity only where needed for interference rejection.
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 adaptation ensures that measurement values can be reliably detected even during high-frequency interference, preventing distortion and maintaining accurate measurement results.
Implementation Method 1
specifically using terminating resistors and additional capacitance to form a capacitive voltage divider
Implementation Method 2
external electromagnetic transient interference radiation
Data Source
AI summary
A connection conductor electrically connects a sensor, the output side of which provides measurement signals, to an intelligent electronic device which is set up to process the measurement signals. The connection conductor has conductor phases arranged insulated from one another, a sensor end on which is formed a conductor input for electrically connecting to an output of the sensor, and an evaluation-unit end which has a conductor output for electrically connecting to an input of the evaluation unit. The two conductor phases extend from the conductor input to the conductor output and are set up to transmit the measurement signals between the output of the sensor and the input of the evaluation unit. In the connection conductor measurement errors due to high-frequency interference are avoided, and the connection conductor is adapted to a frequency range in which the interference occurs.