Protection Relay Phase Correction for Merging Unit Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Distributed protection relay devices face issues with synchronization of A/D conversion timing between merging units, leading to phase differences in digital data, which affects the proper functioning of intelligent electric devices.
Innovation Solution
Incorporating a synchronization signal output device to provide accurate timing synchronization across merging units and intelligent electric devices, using GPS for high-precision timing, and implementing phase correction units within the intelligent electric device to align the phases of digital data from analog and numerical merging units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple merging units with different A/D conversion timing are used to collect system electricity amount, then the device can handle both analog and digital transformers, but phase differences occur in the digital data affecting intelligent electric device operation
Solution Approach 1:
The patent introduces a phase adjustment unit as an intermediary component that receives digital data from merging units with different A/D conversion timings and adjusts their phases. This mediator aligns the phases of digital data before transmitting to intelligent electric devices, resolving the contradiction between handling diverse transformer types and maintaining phase accuracy.
Solution Approach 2:
The patent changes the timing parameter of A/D conversion by introducing a synchronization signal from a GPS receiver. The phase adjustment unit modifies the timing parameter of digital data from different merging units to align their phases, enabling both analog and digital transformers to be handled while maintaining phase accuracy.
2Device complexity
If A/D conversion timing is not synchronized between merging units, then device complexity is reduced, but phase differences cause improper functioning of intelligent electric devices
Solution Approach 1:
The patent implements preliminary action by having the phase adjustment unit pre-adjust the phases of digital data before they are transmitted to intelligent electric devices. The GPS receiver provides advance synchronization signals, and the phase adjustment unit proactively corrects timing differences, ensuring reliable operation without requiring complex real-time synchronization mechanisms.
3Manufacturing precision
If phase correction is implemented in the intelligent electric device, then phase accuracy is improved, but device complexity increases
Solution Approach 1:
The patent extracts the phase correction function from the intelligent electric device and places it in a dedicated phase adjustment unit. This separation allows the intelligent electric device to remain relatively simple while achieving high phase alignment accuracy through the specialized phase adjustment unit that handles all phase correction operations.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An AMU (2) receives analog data indicating a system electricity amount from a CT/VT (8), and converts the input analog data into digital data and outputs the digital data to an IED (1) in synchronization with a synchronization signal supplied from outside. An NMU (3) receives the synchronization signal, generates an A/D conversion request signal, and outputs the A/D conversion request signal to an ECT/EVT (4). The ECT/EVT (4) converts the analog data into digital data and outputs the digital data to the NMU (3) in synchronization with the A/D conversion request signal from the NMU (3). The NMU (3) outputs the input digital data to the IED (1). The IED (1) delays a phase of the digital data input from the AMU (2) to the IED (1), thereby compensating for a difference in timing of A/D conversion between the AMU (2) and the NMU (3) (ECT/EVT (4)).