Smart Meter Time Synchronization via PID Loop
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Solution Overview
Problem
Smart power meters without batteries or supercapacitors struggle to accurately assign time stamps after power loss and restoration, leading to potential revenue loss for utility companies due to synchronization issues with network time.
Innovation Solution
Implementing a proportional, integral, and derivative (PID) loop to synchronize the local system time with the network clock by adjusting it based on the difference between the local clock and network time, eliminating the need for energy storage components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a battery or super capacitor is added to keep the internal clock running during power loss, then time synchronization reliability is improved, but device cost and complexity increase
Solution Approach 1:
The patent removes the battery or super capacitor from the smart meter system entirely. Instead of using energy storage components to maintain clock operation during power loss, the system relies on network time synchronization to correct clock drift after power restoration, thereby simplifying device complexity while maintaining time synchronization reliability through alternative means
Solution Approach 2:
The patent implements a feedback mechanism where the smart meter periodically synchronizes its internal clock with the network time source after power restoration. The system measures the time difference between local and network clocks, then adjusts the local clock accordingly, creating a closed-loop feedback system that maintains accuracy without requiring energy storage components
2Device complexity
If no battery or super capacitor is used to maintain clock operation during power loss, then device cost and complexity are reduced, but time stamping accuracy deteriorates
Solution Approach 1:
The patent prepares for potential power loss by implementing a time tracking mechanism that continuously records the difference between local and network time before power interruption occurs. This preliminary action allows the system to quickly restore accurate time stamping after power restoration by applying the pre-calculated time offset, without requiring energy storage components
Solution Approach 2:
The system employs feedback control where the smart meter periodically compares its internal clock with the network time source and adjusts for drift. After power restoration, the system rapidly synchronizes by measuring the time difference and correcting local time stamps, thereby maintaining measurement precision without batteries or super capacitors
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
Ensures accurate time stamping of power usage data post-power restoration, reducing revenue loss and eliminating the need for batteries or supercapacitors in smart meters.
Implementation Method 1
adjusting the local system time with a proportional, integral, and derivative (PID) loop, wherein the PID loop adjusts the local system time based at least in part on a difference between the local clock and the received network time
Data Source
AI summary
Certain embodiments of the invention may include systems, methods, and apparatus for estimating power time of use. According to an example embodiment of the invention, a method is provided for synchronizing local system time with a network clock for estimating power time of use. The method includes storing power usage data and initial time stamps, wherein the initial time stamps are derived from one or more of a local clock or broadcast network time; receiving data comprising network time; adjusting the local system time with a PID loop, wherein the PID loop adjusts the local system time based at least in part on a difference between the local clock and the received network time; storing, with the power usage data and initial time stamps, an indicator when the difference is greater than a predetermined value; and determining synchronization when the difference is less than or equal to a predetermined value.