Power Line Synchronization Verification Using Remote Relay Time Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electric power delivery systems, accurately determining the synchronization of alternating current waveforms across different segments of a power transmission system is challenging due to fluctuations and the need for precise frequency measurement, which is essential for proper monitoring and protection but often requires multiple sensors and complex connections.
Innovation Solution
A synchronization system that uses a local relay and a remote relay, where the remote relay's measurements, adjusted for transmission delays, are used to determine when the waveforms are synchronous, allowing the local relay to close the circuit breaker efficiently with fewer sensors and simpler connections, leveraging a common time signal for alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors and complex connections are used to achieve precise frequency measurement and waveform synchronization, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by enabling a single sensor at the remote relay to serve multiple functions: measuring frequency, determining waveform synchronization, and providing timing reference for the entire system. The common time signal from GPS satellites serves as a universal reference for all relays, eliminating the need for separate synchronization sensors at each location.
Solution Approach 2:
The patent extracts the frequency measurement and synchronization determination functions from the local relay and concentrates them at the remote relay. By taking out the sensing function to a single location and using communication to transmit the data, the system achieves precise measurement without requiring multiple sensors distributed throughout the system.
2Reliability
If waveform synchronization is verified at each point using local sensors, then measurement reliability is improved, but device complexity increases
Solution Approach 1:
The patent introduces communication signals and a common time reference as intermediaries between the remote relay and local relay. The remote relay's measurements are transmitted through the communication system, and the common time signal acts as a mediator to verify synchronization without requiring direct physical sensing at both locations, thus maintaining reliability while reducing complexity.
3Measurement precision
If precise waveform alignment is required at each point for synchronization, then synchronization accuracy is improved, but the number of sensing devices increases
Solution Approach 1:
The patent uses copying by transmitting the remote relay's frequency and waveform data through the communication system to the local relay. Instead of having the local relay directly sense the waveform, it receives a copy of the remote measurements, which are then used to determine synchronization. This eliminates the need for duplicate sensors while maintaining measurement accuracy.
4Ease of operation
If a common time signal is used for synchronization across distributed relays, then ease of operation is improved, but loss of time occurs due to signal transmission delays
Solution Approach 1:
The patent applies preliminary action by having the remote relay measure the frequency and waveform characteristics in advance before the synchronization decision is made at the local relay. The measurements are transmitted with timing information, allowing the local relay to determine the synchronization window proactively rather than reacting to real-time conditions, thus compensating for transmission delays.
Data Source
AI summary
Systems and methods may be used to determine whether waveforms of at least two transmission lines are synchronous. More particularly, this disclosure relates to sensing operations that use signals received by a local relay and a remote relay to determine whether two waveforms on opposing ends (e.g., supply side and load side, local side and remote side) of a transmission line are synchronous with one another. A system may determine whether a first waveform is synchronous with a second waveform based at least in part on a comparison of delay between a representation of the first waveform and a representation of the second waveform. The system may actuate a device (e.g., close a circuit breaker) in response to determining the first waveform is synchronous with the second waveform.