Inductive Element in Reference Potential Line for PLC Noise Reduction
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Solution Overview
Problem
The existing communication system for vehicle charging, which uses a control line and a reference potential line, suffers from common mode noise conversion into differential mode noise, leading to malfunctioning of the PLC communication device due to inadequate impedance balance and ineffective noise removal by common-mode choke coils.
Innovation Solution
Incorporating an inductive element with higher impedance for noise frequencies than the control signal at the connection point between the reference potential line and the vehicle's reference potential, or within the reference potential line, to improve impedance balance and prevent differential mode noise input to the PLC communication device, and arranging this element inside the connector to prevent damage from vehicle vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a common-mode choke coil is provided in the control line and reference potential line to suppress common mode noise, then common mode noise suppression is improved, but the conversion of common mode noise to differential mode noise cannot be prevented and the PLC communication device still malfunctions
Solution Approach 1:
The patent applies local quality by providing an inductive element specifically in the reference potential line rather than symmetrically in both lines. This asymmetric placement creates different impedance characteristics for common mode and differential mode signals, preventing the conversion of common mode noise to differential mode noise while maintaining common mode noise suppression capability.
Solution Approach 2:
The patent changes the impedance parameter of the reference potential line by introducing an inductive element with specific inductance value. This parameter change creates frequency-dependent impedance that is high for noise frequencies (suppressing common mode noise) while maintaining proper signal transmission, thereby preventing noise conversion and ensuring reliable PLC communication.
2Ease of operation
If the inductive element is placed outside the connector, then installation and maintenance are easier, but the element is vulnerable to damage from vehicle vibrations
Solution Approach 1:
The patent merges the inductive element with the connector structure by providing it inside the connector housing. This integration protects the inductive element from external mechanical damage such as vehicle vibrations while maintaining electrical functionality. The connector structure itself serves as the protective enclosure, eliminating the need for separate mounting brackets or protective housings.
3Stability of the object's composition
If the reference potential line is connected directly to the body ground with low impedance, then the reference potential is stable, but the impedance balance of the PLC communication device becomes unsatisfactory leading to noise conversion
Solution Approach 1:
The patent changes the impedance parameter of the reference potential line by introducing an inductive element. This creates frequency-dependent impedance that maintains low impedance for DC and low-frequency reference potentials (ensuring stability) while presenting high impedance to high-frequency noise signals (preventing conversion to differential mode noise and ensuring reliable PLC communication).
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 configuration effectively reduces differential mode noise input to the PLC communication device, preventing malfunction and minimizing radiated noise, thereby ensuring reliable communication and reducing the risk of inductive element damage from vehicle vibrations.
Implementation Method 1
an inductive element which is provided at a point of connection between the reference potential line and the reference potential or provided in the reference potential line and the inductive element having impedance for a noise having a higher frequency than the control signal is higher than the impedance for the control signal
Data Source
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AI summary
Provided is a communication system in which a noise converted from a common mode into a differential mode and then inputted to a PLC communication device is reduced so that malfunctioning of the PLC communication device is avoidable. A communication system comprising: a control line 1d transmitting a control signal for controlling charging of a battery 10 mounted on a vehicle 1; a reference potential line 1c connected to a reference potential of the vehicle 1 serving as a reference for the control signal; a first PLC communication device 14 connected to the control line 1d and the reference potential line 1c and superposing onto the control signal a differential signal having a higher frequency than the control signal so as to perform communication with an external power supply apparatus 2; and an inductive element 18 which is provided at a point of connection between the reference potential line 1c and the reference potential or provided in the reference potential line 1c and the inductive element having impedance for a noise having a higher frequency than the control signal is higher than the impedance for the control signal.