Bai-Lin Qin

Bio: Bai-Lin Qin is an academic researcher from Schweitzer Engineering Laboratories. The author has contributed to research in topics: Multiple edges & Neighbourhood (graph theory). The author has an hindex of 3, co-authored 4 publications receiving 126 citations.

System for protection zone selection in microprocessor-based relays in an electric power system

Abstract: Graph theory to define busline arrangements as a series of vertices (62) and edges (82). wherein the vertices include the number of busses (62) in the system and the edges include disconnect circuit branches connecting the individual vertices (82). The system operaor chooses a configuration, which determines the status of the various disconnect branches. A processor establishes an incident graph matrix, including positions of all the vertices and edges. The matrix is modified in accordance with graph theory and the condition of the disconnect switches. Graph operations are performed to produce a resulting matrix, which defines vertices and the edges incident thereon into zones of protections. Fault analysis in the busline can then be performed in accordance with each zone of protection.

Reliable busbar protection with advanced zone selection

Abstract: Modern digital relays use innovative algorithms to fulfill busbar protection requirements of fast operating times for all busbar faults, security for external faults with heavy current-transformer (CT) saturation, and minimum delay for evolving faults. This paper describes a reliable protection system that includes busbar protection and advanced zone selection; the protection system is suitable for the protection of multiple busbar arrangements. The protection system consists of several protection principles and measuring techniques using instantaneous and phasor quantities in a unique combination to achieve reliable busbar protection with minimum CT performance requirements.

A new method for protection zone selection in microprocessor-based bus relays

Abstract: Use of graph theory simplifies representation of complex bus arrangements in power system stations. This paper presents a new method, based upon graph theory, for selecting bus protection zones in microprocessor-based relays. We use a typical bus arrangement to illustrate the graphical representation of station arrangements, graph operations, and associated matrix operations. We also describe an implementation of the zone selection method and use two examples to demonstrate the advantages of the method. Using the status of switching devices in the station, the zone selection method provides the relay with real-time bus arrangement information. The bus relay uses this information to assign input currents to a differential protection zone and to select which breakers to trip for a bus fault or breaker failure.

Protection zone selection in an electric power system

Abstract: Graph theory to define busline arrangements as a series of vertices (62) and edges (82). wherein the vertices include the number of busses (62) in the system and the edges include disconnect circuit branches connecting the individual vertices (82). The system operaor chooses a configuration, which determines the status of the various disconnect branches. A processor establishes an incident graph matrix, including positions of all the vertices and edges. The matrix is modified in accordance with graph theory and the condition of the disconnect switches. Graph operations are performed to produce a resulting matrix, which defines vertices and the edges incident thereon into zones of protections. Fault analysis in the busline can then be performed in accordance with each zone of protection.

Integrated protection, monitoring, and control system

Abstract: A method and system for monitoring and controlling a power distribution system is provided. The system includes a plurality of circuit breakers and a plurality of node electronic units. Each node electronic unit is mounted remotely from an associated circuit breaker that is electrically coupled with one of the node electronic units. The system also includes a first digital network, and a first central control unit. The first central control unit and the plurality of node electronic units are communicatively coupled to the first digital network. The method includes receiving digital signals from each node electronic unit at the central control unit, determining an operational state of the power distribution system from the digital signal, and transmitting digital signals to the plurality of node electronic units such that the circuit breakers are operable from the first central control unit.

Circuit protection system

Abstract: A circuit protection system including a CCPU (28) is provided that provides dynamic zones of protection (895, 896) for the circuit. The zones of protection (895, 896) can be based in part upon the topology of the circuit. The protection system can perform various dynamic zone protective functions for the zones of protection (895, 896).

Adaptive Agent-Based Wide-Area Current Differential Protection System

Abstract: This paper proposes a multiagent-based adaptive wide-area current differential protection system. A power grid is divided into primary and backup protection zones dynamically online with the help of a developed expert system, and the relay agents of these zones cooperate to perform a differential relaying function. Predictive self-healing strategies have been proposed to prevent misoperation of the relay agent, and the communication system has been simulated. The performance of the proposed adaptive wide-area current differential protection system based on computer simulation is presented in this paper.

Agent-based self-healing protection system

Abstract: This paper proposes an agent-based paradigm for self-healing protection systems. Numerical relays implemented with intelligent electronic devices are designed as a relay agent to perform a protective relaying function in cooperation with other relay agents. A graph-theory-based expert system, which can be integrated with supervisory control and a data acquisition system, has been developed to divide the power grid into primary and backup protection zones online and all relay agents are assigned to specific zones according to system topological configuration. In order to facilitate a more robust, less vulnerable protection system, predictive and corrective self-healing strategies are implemented as guideline regulations of the relay agent, and the relay agents within the same protection zone communicate and cooperate to detect, locate, and trip fault precisely with primary and backup protection. Performance of the proposed protection system has been simulated with cascading fault, failures in communication and protection units, and compared with a coordinated directional overcurrent protection system.

Distributed bus differential protection using time-stamped data

Abstract: A distributed busbar protection system using time-stamped data gathered from measurement devices in an electrical power system bus arrangement by respective intelligent electronic devices (IEDs). The IEDs may derive the timestamp information from a clock or other time source, which may be synchronized to a common time source and/or an absolute time. The time-stamped measurement data may be used by a protection device to monitor and/or protect the electrical power system. The protection device may include a real-time vector processor, which may time-align the time-stamped data, determine one or more bus differential protection zones, and implement a differential protection function within each of the protection zones. One or more protective control signals may be transmitted to the IEDs to trip the corresponding breakers and clear the bus fault.