PLC Differential Signaling With Ground-Wire Noise Isolation
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Solution Overview
Problem
Power line communication (PLC) networks face decreased transmission rates due to power grid noise and electrical device noise, which are exacerbated by the increasing number of electrical devices in the circuit, leading to a lower signal-to-noise ratio.
Innovation Solution
A PLC control method and apparatus that utilizes a differential signal processing circuit to transmit signals through neutral, live, and ground wires, dynamically switching connections based on transmission rate thresholds to optimize signal transmission and minimize noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If signals are transmitted through neutral wire and live wire in differential mode, then broadband network access is achieved, but transmission rate decreases due to power grid noise and electrical device noise
Solution Approach 1:
The patent introduces a ground wire as an intermediary transmission path to replace the noisy live wire or neutral wire when noise interference is detected. The ground wire acts as a cleaner alternative path for signal transmission, isolating the differential signal from power grid noise and electrical device noise that affect the traditional live-Neutral transmission path.
Solution Approach 2:
The patent implements dynamic switching between different transmission paths (neutral-live wire, neutral-ground wire, ground-live wire) based on real-time transmission rate monitoring. When the transmission rate on the current path falls below a threshold, the system dynamically changes to an alternative path, making the transmission system adaptive to changing noise conditions.
2Object-affected harmful factors
If the first path between differential signal processing circuit and neutral wire is disconnected and ground wire is used instead, then noise isolation is improved, but device complexity increases due to additional switching control
Solution Approach 1:
The patent divides the signal transmission function into separate controllable segments by introducing switching components that can independently connect or disconnect the ground wire path. This segmentation allows the system to isolate noise-affected paths while maintaining the ability to switch to cleaner paths, reducing overall noise impact without requiring complete system redesign.
Solution Approach 2:
The patent employs feedback control by monitoring transmission rates and using this information to control the switching of transmission paths. When transmission rate drops below a threshold, the system automatically switches to an alternative path; when transmission rate recovers, it can switch back. This feedback mechanism manages the complexity of switching control by making it responsive to actual transmission conditions rather than requiring complex predetermined control logic.
Data Source
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AI summary
Embodiments of this application provide a PLC control method and apparatus. The method includes: controlling to transmit a first signal through a neutral wire and a path between the neutral wire and a differential signal processing circuit; controlling to transmit a second signal through a live wire and a path between the live wire and the differential signal processing circuit; and disconnecting the path between the differential signal processing circuit and the neutral wire or the live wire, conducting the differential signal processing circuit to a ground wire, and when a transmission rate of the ground wire is greater than or equal to a preset transmission rate threshold, transmitting the first signal or the second signal through the ground wire and a path between the ground wire and the differential signal processing circuit. Because interference to the ground wire in a power line is small, any signal in the differential signal processing circuit is transmitted through the ground wire, so that a part of power grid noise is isolated, and a transmission signal-to-noise ratio increases, thereby increasing a transmission rate of a power line communication modem.