Self-Powered Power Sensor Time Stamping for Accurate Power Factor
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Solution Overview
Problem
Current self-powered power sensors (SPPSs) face limitations in accurately measuring power consumption due to challenges in synchronizing wireless measurements of current and voltage, leading to inaccuracies in power factor calculation.
Innovation Solution
A method and system for synchronizing a central controller with self-powered power sensors (SPPSs) that involves sampling electrical signals, estimating sample times, generating packets with synchronization information, and transmitting time offset values to calculate electrical parameters, allowing for accurate power factor determination without requiring zero-crossing detection by the SPPS.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless connection is used between current and voltage sampling, then remote measurement capability is improved, but measurement accuracy deteriorates due to synchronization difficulties
Solution Approach 1:
The system performs preliminary time-stamping of samples at the SPPS before wireless transmission. This preliminary action captures the exact sampling time locally, eliminating the need for complex real-time synchronization during data collection and enabling accurate post-processing of power factor calculations at the central controller.
Solution Approach 2:
The patent introduces time-stamp values as an intermediary element that bridges the wireless connection gap between SPPS and central controller. These time-stamps serve as a mediator that carries timing information through the wireless channel, allowing the central controller to reconstruct synchronized voltage and current waveforms without requiring active synchronization during transmission.
2Measurement precision
If SPPS activates in receive mode for synchronization, then synchronization accuracy is improved, but energy consumption increases
Solution Approach 1:
The SPPS performs self-service by autonomously generating and transmitting time-stamp information for its own samples without requiring external synchronization signals or activate receive mode. This self-service approach allows the SPPS to maintain measurement capability while remaining in a low-power state, as it only needs to transmit data rather than actively receive and process synchronization signals.
Solution Approach 2:
The system performs preliminary time-stamping of samples at the SPPS before wireless transmission. This preliminary action captures the exact sampling time locally, eliminating the need for complex real-time synchronization during data collection and enabling accurate post-processing of power factor calculations at the central controller.
Data Source
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AI summary
A system and method for the synchronization of a central controller wirelessly connected to at least one self-powered power sensor (SPPS). The method includes: sampling an electrical signal by at least one SPPS; estimating by the at least one SPPS a time of a sample of the electrical signal; generating a packet comprising packet components including a preamble, a synchronization field, and message data; generating synchronization information for the synchronization field of the packet; transmitting wirelessly the packet components; determining a time offset value for the packet, the time offset calculated from the time of the sample of the electrical signal and a transmission time-stamp of the synchronization information; and transmitting the time offset value by appending it to the packet, wherein the time offset value is used for the purpose of calculating at least an electrical parameter.