PLC Time Synchronization via Voltage Zero-Crossing Detection
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Solution Overview
Problem
Current power line communication (PLC) networks face challenges in achieving precise time synchronization between nodes, leading to inconsistencies in cyclic wave data collection, particularly due to varying implementation methods and low synchronization accuracy among different vendors, resulting in errors up to the millisecond level.
Innovation Solution
A time synchronization method is introduced where a head end node detects voltage zero-crossing points and sends timestamp data to tail end nodes, using a voltage zero-crossing detection circuit to ensure consistent time synchronization across the network, with the option to include zero-crossing counts for improved accuracy, especially when crystal oscillators have low quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage zero-crossing detection circuit is added to each node, then time synchronization precision is improved, but device complexity increases
Solution Approach 1:
Each node in the PLC network autonomously detects voltage zero-crossing points using its own detection circuit and independently generates synchronized timing signals, eliminating the need for complex centralized synchronization control mechanisms
Solution Approach 2:
The patent replaces complex electronic synchronization circuits with a simple voltage zero-crossing detection mechanism, using the inherent electrical characteristics of the power line to generate timing signals
2Adaptability or versatility
If PLC network layers are increased to expand coverage, then adaptability is improved, but time synchronization accuracy deteriorates due to larger errors reaching millisecond level
Solution Approach 1:
The patent divides the PLC network into multiple independent synchronization domains, where each node independently detects zero-crossing points and generates timing signals, preventing error accumulation across network layers
Solution Approach 2:
The patent utilizes the periodic nature of voltage zero-crossing events (occurring at fixed intervals corresponding to the power frequency) to generate regular synchronization pulses that maintain consistent timing accuracy regardless of network depth
3Adaptability or versatility
If different vendor implementation methods are used, then adaptability is improved, but time synchronization accuracy deteriorates due to lack of standardized precision
Solution Approach 1:
The patent implements a universal voltage zero-crossing detection mechanism that can be applied by any vendor in any PLC network configuration, providing a standardized approach that ensures consistent synchronization accuracy across different implementations
Solution Approach 2:
The patent changes the synchronization reference from vendor-specific clock signals to the universal voltage zero-crossing parameter, which is inherently available in all PLC networks and provides a common reference point for all nodes regardless of vendor
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 method enables precise time synchronization within PLC networks, ensuring consistent and accurate collection of data by aligning nodes with a reference time, thereby reducing inconsistencies and improving data quality.
Implementation Method 1
The head end node and the tail end node each have a function of detecting a voltage zero-crossing point. Specifically, a voltage zero-crossing detection circuit may be added to each of the head end node and the tail end node to detect a voltage zero-crossing point.
Data Source
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AI summary
This application discloses a time synchronization method, applied to a PLC network that includes a head end node and at least one tail end node connected to the head end node. The method includes: The head end node generates data about voltage zero-crossing points based on reference time, where the data about the voltage zero-crossing points includes zero-crossing time points of the voltage zero-crossing points. When a first timing point arrives, the head end node sends first information to the tail end node, where the first information includes a timestamp of a first zero-crossing point, the first zero-crossing point is a voltage zero-crossing point closest to the first timing point, and the timestamp of the first zero-crossing point is used by the tail end node to determine a zero-crossing time point of a second zero-crossing point. Embodiments of this application further provide a corresponding device and a storage medium. In the technical solutions of this application, precise time synchronization may be implemented between different nodes in the PLC network based on consistency and a periodicity that are generated based on voltage zero-crossing points, to ensure that the nodes in the PLC network can maintain precise time synchronization, and avoid inconsistency of cyclic waves of synchronously collected data.