Automatic Protection Research Articles

Evolution Pathway Towards Wide Area Monitoring and Protection—A Real-World Implementation of Centralized RAS System

Remedial action scheme (RAS) is an automatic protection system designed to maintain system reliability. As result of green initiatives and mandates, there will be a proliferation of RAS in order to accommodate many new generation interconnections. With enabling technologies such as advanced intelligent electronic devices, fast computing technologies, utilities' extensive telecommunication network infrastructure, and the continued development of international standards, the opportunity allows a breakthrough in wide area monitoring and protection solutions. This paper describes how Southern California Edison systematically moved through stages from problem definition to ultimately deployment and system operation. Both the business and technical challenges during the project execution are discussed. Starting with the pressure on business practice, the evolutionary process of problem solving not only demonstrated how advanced information and telecommunication technologies can address the power utility business needs, but also paved a pathway for even more advanced wide area monitoring and protection applications.

The Method of Electric Power Communication Network Time Delay Control Based on T-MPLS

Based on the fabric of national electric power system, the types and causes of delay in the network is investigated. The evolution guideline is deeply discussed. Mechanism in T-MPLS such as packet switching, plastic limit, automatic protection switching and multi-service package adapter are utilized to improve the time delay of the power communication network. It is to lay the foundation for the next generation of Smart Substation.

Research of Ethernet Ring Protection Technology

Ethernet ring networks are used widely recently, and the research on the ring protection switching is carried out. Spanning Tree Protocol (STP) was the first technology to control ring networks to avoid the storm. Rapid Spanning Tree Protocol (RSTP) is an upgraded version of STP[1]. RSTP can provide shorter convergence time than STP. Ethernet Automatic Protection switching (EAPS) is designed for a single ring topology [2]. The convergence time of EAPS is below 50ms and EAPS can meet the real-time requirements and high-reliability requirements of network services.G.8032 is a standardized scheme for achieving sub-50ms service protection in ring topologies which is recommended by ITU-T[3]. This paper intelligent Ethernet ring protection technologes about Spanning Tree Protocol, RFC3619 and G.8032 .These technologies appear in different times, and have their advantages and disadvantages. This article outlines these Ethernet ring protection switching technology and explains their basal principles.

Increasing metro line capacity by optimisation of track circuit in a speed code Automatic Train Protection system

When analyzing a railway operation, multiple issues must be taken into account to obtain the best results in terms of safety, efficiency and flexibility. In this project, carried out in collaboration between CITEF and a European metro line, a tool has been developed and implemented. Based on the line data provided by the metro line, the signalling system (distance to go/speed signalling), the main characteristics of the rolling stock, etc., information can be obtained for modelling/modifying the line, changing or removing/inserting track circuits or even changing the maximum running speeds on those track circuits. Travel times, line frequencies, bottlenecks, and degraded conditions are also analyzed from the simulations, so that finally the best headway to be implemented on the line can be proposed for the user, who is able to know how to improve the main line features like capacity and frequency of trains. Integrating distance to go and speed signalling into the set of parameters, is another capability proposed. Fundamental information on the signalling system capacity can be obtained simply by running the algorithms designed for this task along with the changes in order to carry it out.

A Strategy to Formalize Specification and Its Application to an Advanced Railway System

This paper proposes a novel strategy for formally analyzing functional requirements specification (FRS) and applies it to the Automatic Train Protection and Block (ATPB) system, which is proposed to reconstruct conventional rail lines in Japan. Based on the FRS in natural language, firstly, dynamic state transitions are extracted to express the operational mechanisms and determine the system parameters. A complete model of the ATPB system is then established using Unified Modeling Language (UML) to express the system structure graphically and explicitly. After achieving a common understanding, a VDM++ model is established formally to redescribe the original FRS of the ATPB system which is written in natural language (i.e. Japanese). Following that, in order to ensure internal consistency of the specification, proof obligations of the VDM++ model are discharged. Furthermore, a comprehensive testing is implemented to ensure that the FRS meets actual requirements. Finally, the system is simulated strictly in accordance with the formal specification. Without any runtime errors, collisions or derailments, the results of the simulation demonstrate the high quality and safety of the specification.

Simulation of air streams at oil transshipment complex in order to determine an optimal location for buildings and facilities

While operating any hazardous production facility there is a possibility of a failure or an incident which can bring serious harm to human health and life as well as to the environment. At the design stage already, all the manufacturing processes at hazardous production facilities must be considered as potentially dangerous in order to have a possibility to make appropriate corrections before starting construction. In case the buildings and facilities are located unsuccessfully, there can be areas of accumulation of harmful and hazardous substances in the air that makes the risk of serious aftermath increased. Simulation of air streams by means of modern software helps to detect dead zones. In the process of simulating hazardous processes at this hazardous production facility and by visualization of calculations in the FlowVision software, all cardinal direction air streams speeds were determined and dead zones were examined. In order to keep constant control over contaminants concentration and in accordance with the enforceable standards, the production area of open processing units at refineries must be equipped with automatic protection systems. Protection systems must be chosen in accordance with the production type and the process parameters, changing of which may result in an accident, considering all possible cases of emergency occurring when automatic control systems fail. One of the main functional parts of the system is a gas analyzer which measures strength of contaminant exposure. In accordance with TU-gas-86 “Specifications for installation of signalizes and gas analyzers”, a location scheme for CCC-903M stationary gas analyzers at the site is offered as a measure to improve safety at this facility.

Formalizing a subset of ERTMS/ETCS specifications for verification purposes

ERTMS is the standard railway control-command and signaling system which aims to ensure railway interoperability throughout Europe while enhancing safety and competitiveness. ERTMS is composed of two main subsystems which include GSM-R, a radio system for enabling communication between the train and the traffic management center and ETCS, an automatic train protection system (ATP) to replace the existing national ATP systems. The ERTMS specifications are defined by means of standard documents which set out the requirements ensuring interoperability. These documents evolve regularly to give rise to successive versions. The ERTMS/ETCS standard defines different levels and operation modes according to various trackside and onboard setups and some operational conditions. Given the complexity and the high criticality of railway operation, verification and validation (V&V) are crucial tasks in railway application development.In this paper, after setting the background and the motivations, a mechanizable formalization of a subset of ERTMS/ETCS specifications relative to ETCS modes and transitions is developed. The present work aims to offer a readily available model for formal V&V. Using formal techniques to check SRS is highly recommended to tackle the complexity of the defined requirements and prevent specification errors. Model-checking technique, which is targeted here, offers exhaustive analysis of the system behavior based on its model and is highly automated, since it is supported by software tools. Based on the last available version of SRS specifications, a progressive process is undertaken to get a formal model which makes explicit the various modes characterized by their respective active functions, as well as the numerous combinations of conditions for switching between modes. The various steps guiding the translation of the SRS literal specifications into a formal model are explained. As will be shown through different examples, the obtained model is a convenient basis to check safety, interoperability and liveness properties.

Karst show caves – how DTN technology as used in space assists automatic environmental monitoring and tourist protection – experiment in Postojna Cave

Abstract. The paper presents an experiment demonstrating a novel and successful application of delay- and disruption-tolerant networking (DTN) technology for automatic data transfer in a karst cave early warning and measuring system. The experiment took place inside the Postojna Cave in Slovenia, which is open to tourists. Several automatic meteorological measuring stations are set up inside the cave, as an adjunct to the surveillance infrastructure; the regular data transfer provided by the DTN technology allows the surveillance system to take on the role of an early warning system (EWS). One of the stations is set up alongside the railway tracks, which allows the tourist to travel inside the cave by train. The experiment was carried out by placing a DTN "data mule" (a DTN-enabled computer with WiFi connection) on the train and by upgrading the meteorological station with a DTN-enabled WiFi transmission system. When the data mule is in the wireless drive-by mode, it collects measurement data from the station over a period of several seconds as the train without stopping passes the stationary equipment, and delivers data at the final train station by the cave entrance. This paper describes an overview of the experimental equipment and organization allowing the use of a DTN system for data collection and an EWS inside karst caves where there is regular traffic of tourists and researchers.

무선통신기반 열차제어시스템 상호운영성 연구

연구는 무선통신기반 열차제어시스템의 상호운영성(interoperability)을 확보하기 위하여 열차제어와 관련된 위험원 분석, 열차제어시스템의 기능요구사항 설정 및 차상과 지상ATP(Automatic Train Protection)장치의 기능배치를 포함하고 있다. 개방형 무선통신기술을 활용하고, 지상과 차상에서 수행되는 열차제어시스템의 기능배치를 표준화화여 상호운영성을 확보할 수 있으며, 이를 통하여 철도망의 통합운영체계를 구축할 수 있다. 상호운영성을 지원하는 열차제어시스템의 기능을 지상과 차상에 배치하기 위해서는 위험원 분석과 시스템 요구사항 정의를 필요로 한다. 열차제어시스템의 위험원으로 열차안전간격제어와 열차제한속도초과를 설정하여 위험원 요인을 확인하였다. 또한 위험원 요인이 열차제어시스템에 미치는 영향을 확인하고 열차제어시스템의 하부장치의 기능요구사항과 ATP의 지상기능과 차상기능 배치를 정의하였다. This paper analyzes the hazard related to train control, the functional requirements for atrain control system(TCS) and the automatic train protection(ATP) functional allocation that ensures the interoperability of a radio communications-based TCS. In addition, the interoperability can be obtained using wireless communications technology standards and standardized functional allocations of TCS performed on the wayside and onboard. Using this information, an integrated operating system for a rail network can be constructed. The functional allocations of TCS that support interoperability, require hazard analysis of TCS and definition of the system requirements. The hazard factors for a TCS are confirmed through setting the train safety space control and train speed limit excess. Furthermore, this paper determines the impact of the hazard factors on the TCS and, defines the functional requirements for the TCS subsystems and the ATP wayside and onboard functional allocations.

基于形式化测试的实时系统变更后安全性验证

It is necessary and competitive to verify the desired safety properties on the changed implementation during the maintenance phase of a safety critical system. Software model checking and program veri cation are the popular applied automatic safety veri cation techniques on the program level. In the paper, we propose a formal testing method for the system behaviors which tries to verify the desired safety properties for the changed implementation by means of conformance testing. Firstly, we prove the correctness of our method based on timed input/output automata and its semantics model. Secondly, we present a regression testing generation framework of safety veri cation for the changed implementation. Compared with other real time testing methods, our method can not only detect the common non-conformance defects but also conclude the satisfaction with the desired safety properties. The method is illustrated with a changing requirement of the automatic train protection function in the train control system.

The Research of Website Tamper-Resistant Technology

Webpage tamperproof technology is a website technology to protect webpage not to display tamper contents and to carry out real-time recovery. Webpage tamperproof system uses advanced Web server core embedded technology and tamper detection technology based on cryptography to give a comprehensive protection of static webpage and dynamic webpage of the website. Webpage tamperproof system supports the automatic release, tamper detection, application protection, warning, and real-time recovery of webpage, guarantees the safety of various links of transmission, identification, address access, form submission, and auditing, fully eliminates the possibility of access to tampered webpage in a real-time manner, and puts an end to any tamper of backstage database in a manner of Web.

An Experimental Study of Automatic Water Cannon Systems for Fire Protection of Large Open Spaces

An experimental study is conducted to evaluate the performance of automatic water cannon systems for protecting fire hazards in large-open spaces. As part of this study, typical fire hazards encountered in large-open spaces are simulated to allow for a comparison of water cannon and automatic fire sprinkler protection. Tests are performed to characterize response time, water distribution and effectiveness of protection of the selected water cannon system. Results show that, in general, water cannon can respond to fire events in large-open spaces much faster than sprinklers. Under certain conditions, water cannon can also control and/or suppress the fire. However, further improvement of automatic water cannon technology is needed to optimize system performance for various commodity fires that may occur in large-open spaces.

The Research on Ethernet Ring Protection Switching

TU-T has recommended a standardized scheme for achieving sub-50ms service protection in ring topologies through Ethernet Ring Protection Switching (ERPS) specified in G.8032 recommendation[. ERPS provides a means to reliably achieve carrier-class network requirements for Ethernet topologies forming a closed loop. This article outlines an Ethernet ring protection switching mechanism and explains how its automatic protection switching (APS) protocol works. In addition, this article illustrates a sample scenario with failure and recovery.

Design and realization of a novel position-and-speed measurement system with communication function for the low-speed maglev train

The low-speed maglev train system is a new type rail transportation system. The position-and-speed measurement system and the train-ground communication system are the cores of the Automatic Train Control (ATC) system and Automatic Train Protection (ATP) system. However, the position-and-speed measurement system and the train-ground communication system at present are separate, and this raises the maintenance and the operation cost of the maglev train. This paper based on the characteristics of some conventional induction looped-cable systems designs a novel induction looped-cable system. The system realizes the position-and-speed measurement function and the train-ground full-duplex communication function for the maglev train system. The experiment results show that the system can operate reliably on the practical maglev test line.

Automatic Protection Schemes for Distribution System with Open and Closed-loop

Protection issues in distribution systems which are to be operated in open and closed-loop modes in a smart grid are studied and a generalized protection setting method is proposed to meet the new requirements. The developed setting method assumes a conventional over-current protection scheme for the system with reclosers and over-current relays. In a closed-loop mode, it identifies protective devices that have to be sacrificed in order to maximize protection coordination for bidirectional fault current flow. The proposed setting method has been tested on many systems with different complexity and is proved effective.

Data configurations in railway signalling engineering - an application of enterprise systems techniques

Railway signalling system is a safety-critical system to ensure railway safety and its development cost is huge. It is of great economic value to apply the generic signalling systems in different environments through configuration of different application data. In this paper, a new method to configure the application data completely and accurately is illustrated; in particular, a technique called automatic generation technology is introduced to automatically configure the functional logic of safety-critical systems, i.e. computer-based interlocking (CBI) system and automatic train protection (ATP) system. All of the application data are collected from the workflow among various departments through the enterprise system (ES). Some application data are represented by models employing automatic generation technology, and the functional logic is then obtained through analysis using these models. A configuration platform based on the ES is developed in which both the efficiency and accuracy of the application data configuration are significantly improved. In addition, it is capable of reducing human errors to a maximal extent.

Design of Monitor and Control System of Screw Pump Oil Production Based on ATT7022

Design a working condition monitoring and intelligent diagnosis system for screw pump based on the ATT7022 chip. Achieve real-time acquisition, storage, analysis of the driving motor electrical parameters of three-phase voltage, current, frequency, active and inactive power, power factor, and the fluid parameters of screw pump production well pressure, pressure, temperature. Accomplish monitoring, alarm and automatic protection the screw pump failure of rod breaking, pump sticking, vacuum, lack of power phase. Using PIC microprocessor to automatic compensate the screw pump motor power, to improve the work efficiency.

Innovative Management of Wheel-Rail Adhesion Conditions in Localization Algorithms for the Automatic Train Protection

In the modern railway network, Automatic Train Protection and Control (ATP-ATC) systems are fundamental to increase the infrastructure capacity, maintaining a proper level of operation safety. Odometry is a relevant on-board module, since it estimates the speed and the travelled distance of a railway vehicle along the track. Its reliability affects the definition of allowed speed profiles, in order to prevent collisions from a driver's failure to observe a signal. Typically the dead reckoning relies on encoders providing an accurate estimation of the train speed only when good adhesion conditions between wheel and rail occur. In presence of wheel sliding the estimation error may become very high. In this paper the management of adhesion conditions is enhanced using an Inertial Measurement Unit (IMU) which improves the adhesion condition detection and the speed and travelled distance estimation. The testing of the proposed algorithm is performed through a testing simulator, set up by the MDM Lab and used to speed up the algorithm tuning, capable of replicating in a realistic way the motion dynamic effects of a railway vehicle on inertial sensors. The Hardware-In-The-Loop test rig is composed of a Matlab-Simulink TM three-dimensional multibody model of a railway vehicle, a commercial anthropomorphic manipulator with spherical wrist and an IMU designed by ECM Spa (Pistoia, Italy). The experimental results are compared to the performance requirements fixed by the European Rail Traffic Management System (ERTMS).

Design and Application of Automation System for Reconstruction and Expansion of Small Oilfield Station

With the rolling development of Suqiao-Wenan Oilfield, the original small treatment station-Station Wen 11, cannot satisfy production requirements. It is necessary to reform and expand the crude oil storage and treatment capacity, water-injection capability and natural gas treatment capacity, on the basis of the original construction; establish new crude oil treatment, fire-fighting and heating systems, as well as supporting systems like crude oil loading and unloading, automatic monitoring and cathodic protection systems, to form a medium-sized centralized oil-gas-water treatment station with complete functions. This paper introduces design, implementation and application effect of the process automation system after Station Wen 11 undergoes reconstruction and expansion.

Electrochemically Oxidized Electronic and Ionic Conducting Nanostructured Block Copolymers for Lithium Battery Electrodes

Block copolymers that can simultaneously conduct electronic and ionic charges on the nanometer length scale can serve as innovative conductive binder material for solid-state battery electrodes. The purpose of this work is to study the electronic charge transport of poly(3-hexylthiophene)-b-poly(ethylene oxide) (P3HT-PEO) copolymers electrochemically oxidized with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt in the context of a lithium battery charge/discharge cycle. We use a solid-state three-terminal electrochemical cell that enables simultaneous conductivity measurements and control over electrochemical doping of P3HT. At low oxidation levels (ratio of moles of electrons removed to moles of 3-hexylthiophene moieties in the electrode), the electronic conductivity (σe,ox) increases from 10(-7) S/cm to 10(-4) S/cm. At high oxidation levels, σe,ox approaches 10(-2) S/cm. When P3HT-PEO is used as a conductive binder in a positive electrode with LiFePO4 active material, P3HT is electrochemically active within the voltage window of a charge/discharge cycle. The electronic conductivity of the P3HT-PEO binder is in the 10(-4) to 10(-2) S/cm range over most of the potential window of the charge/discharge cycle. This allows for efficient electronic conduction, and observed charge/discharge capacities approach the theoretical limit of LiFePO4. However, at the end of the discharge cycle, the electronic conductivity decreases sharply to 10(-7) S/cm, which means the "conductive" binder is now electronically insulating. The ability of our conductive binder to switch between electronically conducting and insulating states in the positive electrode provides an unprecedented route for automatic overdischarge protection in rechargeable batteries.