Point on Wave Switching Controller for Transfer Bay Circuit Breakers
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Solution Overview
Problem
Current point on wave controllers at transfer bays in power systems have lower accuracy and more complex switching procedures compared to those in other bays, leading to improper switching operations and reduced circuit breaker life expectancy.
Innovation Solution
A method and system for performing point on wave switching in multiphase electrical systems, where a second controller receives system characteristics data, estimates switching times, and operates circuit breakers at the estimated times for transferring subsystems between buses, utilizing processors, memory modules, and communication over IEC 61850 channels to ensure precise switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If point on wave controllers are used at transfer bays, then switching control is achieved, but accuracy is lower and procedure is more complex compared to other bays
Solution Approach 1:
The switching procedure is segmented into distinct phases: voltage waveform detection, zero-crossing identification, timing calculation, and command execution. This segmentation simplifies the overall complex procedure into manageable steps that can be systematically implemented and verified, reducing procedural complexity while maintaining accuracy at transfer bays.
Solution Approach 2:
The system performs preliminary detection of voltage waveform characteristics and calculates the optimal switching time in advance before actually executing the circuit breaker operation. This preliminary action allows the controller to prepare the precise switching command with accurate timing, improving measurement precision while streamlining the execution process.
2Reliability
If traditional point on wave switching is used at transfer bays, then switching operations are performed, but improper switching occurs reducing circuit breaker life expectancy
Solution Approach 1:
The system continuously monitors voltage waveform characteristics and provides feedback to adjust the switching timing calculation. This feedback mechanism ensures that the switching operation is properly synchronized with the voltage waveform, preventing improper switching that would reduce circuit breaker life expectancy, while the automated feedback loop maintains operational simplicity.
Solution Approach 2:
The controller dynamically adjusts switching parameters such as timing offset and synchronization point based on detected voltage waveform characteristics. By changing these parameters adaptively, the system ensures proper switching conditions are met, extending circuit breaker life, while the automated parameter adjustment keeps the operation simple for users.
Data Source
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AI summary
In aspects, the present invention provides a method of performing point on wave switching in a multiphase electrical system (100) having a first circuit breaker (137) connected a first bus (120), the first circuit breaker (137) operated by a first controller (135), a second circuit breaker (197) connected to a second bus (110), the second circuit breaker (197) operated by a second controller (195), and a subsystem transferred from the first bus (120) to the second bus (110). The method includes receiving (210), by the second controller (195), system characteristics data of the subsystem, estimating (220), by the second controller (195), a time for switching based on the received system characteristics data of the subsystem and operating time of the second circuit breaker (197), operating (230), by the second controller (195), the second circuit breaker (197) at the estimated time for switching, for switching the subsystem.