PLC Network Clock Synchronization via AC Phase Reference
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Solution Overview
Problem
Current synchronization methods for Power Line Carrier (PLC) networks, such as those defined by the IEC 61588 standard, are not suitable due to asymmetrical message propagation delays and excessive signaling traffic, leading to inaccurate clock synchronization and bandwidth issues, which affects the precision and reliability of electricity distribution network management.
Innovation Solution
A method that synchronizes a slave station's clock with a master station's clock by determining a common time reference from the alternating current in the PLC network, reducing signaling traffic by transmitting only a synchronization frame and using phase shift information to adjust the clock value, thereby improving temporal precision and reducing processor load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the IEC 61588 standard synchronization protocol is used, then clock synchronization is attempted, but message propagation delays are asymmetrical and signaling traffic is excessive
Solution Approach 1:
The invention extracts the synchronization function from the complex IEC 61588 protocol and implements it using a simplified approach based on alternating current phase information. Instead of using multiple synchronization messages with timestamps, the system uses the inherent phase reference of the alternating current to directly determine clock synchronization, thereby reducing protocol complexity while maintaining precision.
Solution Approach 2:
The alternating current serves as an intermediary that provides a common time reference for all stations. By using the phase information of the alternating current as a mediator, the system avoids the need for complex message exchange protocols. The phase reference acts as a shared reference that enables synchronization without requiring asymmetric delay compensation mechanisms.
2Measurement precision
If multiple synchronization messages are exchanged to correct propagation delay, then synchronization precision is improved, but signaling traffic increases
Solution Approach 1:
The invention extracts the essential synchronization function from the multi-message PTP protocol and implements it using a single reference based on alternating current phase information. This eliminates the need for multiple synchronization messages (Sync, Follow_Up, Delay_Req, Delay_Resp) while maintaining time measurement precision through the inherent stability of the AC phase reference.
Solution Approach 2:
The alternating current provides its own phase reference that serves the synchronization function without requiring additional signaling traffic. The system uses the self-contained phase information of the AC signal to determine clock synchronization, making the synchronization process self-service and eliminating the need for complex message exchange protocols that consume bandwidth.
3Measurement precision
If PTP protocol is implemented with symmetrical propagation delay assumption, then clock synchronization is achieved, but the assumption does not hold in PLC networks
Solution Approach 1:
The invention accepts and utilizes the asymmetrical nature of PLC network propagation delays rather than attempting to correct for them. By using the alternating current phase reference, which is common to all stations regardless of their position in the network, the system makes synchronization reliable without requiring the symmetrical delay assumption. The phase reference provides a consistent time基准 that works equally well for all stations despite asymmetrical physical distances and propagation characteristics.
Solution Approach 2:
The alternating current phase information acts as an intermediary that provides a common time reference independent of network topology and propagation delays. This mediator approach allows stations at different distances and positions in the PLC network to synchronize reliably using a shared reference that is not affected by asymmetrical propagation characteristics.
Data Source
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AI summary
The invention relates to a method for synchronising a clock signal of a slave station with a clock signal of a master station, the clock signal of the master station being provided by an external reference means, the two stations being connected by a powerline communication (PLC) network. The method comprises the following steps: determining a shared time reference for the two stations from an AC current of said PLC network; updating (23) the clock signal of the slave station by applying a clock value determined from the shared time reference.