1、BRITISH STANDARD BS7404-1.2: 1991 IEC870-1-2: 1989 Telecontrol equipment and systems Part1: General considerations Section1.2 Guide for specificationsBS7404-1.2:1991 This British Standard, having been prepared under the directionof the Power Electrical Engineering Standards Policy Committee, was pub
2、lished underthe authority of the Standards Board and comes intoeffect on 31 July1991 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference PEL/89 Draft for comment 89/27226 DC ISBN 0 580 19722 0 Committees responsible for this British Standard The preparat
3、ion of this British Standard was entrusted by the Power Electrical Engineering Standards Policy Committee (PEL/-) to Technical Committee PEL/89, upon which the following bodies were represented: Association of Consulting Engineers BAMEMA (BEAMA) BEAMA Ltd. EEA (the Association of Electronics, Teleco
4、mmunications and Business Equipment Industries) Electricity Supply Industry in United Kingdom GAMBICA (BEAMA Ltd.) North of Scotland Hydro-Electric Board Telecommunication Engineering and Manufacturing Association Transmission and Distribution Association (BEAMA Limited) Amendments issued since publ
5、ication Amd. No. Date CommentsBS7404-1.2:1991 BSI 08-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Object 1 3 Description of the telecontrol system and its functions 1 3.1 Description of the telecontrolled (or telemonitored) process 1
6、3.2 Functions of telecontrol systems 2 3.3 Data quantities 4 3.4 Man-machine interface 6 3.5 Characteristics of the data flow 6 4 Specification of the data transmission network 6 4.1 Data network configuration 6 4.2 Specification of telecontrol data transmission 7 4.3 Representation of the planned d
7、ata network in a block diagram 7 5 Equipment specifications 7 5.1 Overview of the equipment of telecontrol systems 7 5.2 Specifications of the environmental conditions 8 5.3 Specifications of interfaces between the different equipment oftelecontrolsystems 8 5.4 Specifications of the power supply equ
8、ipment 9 5.5 Mechanical specifications 9 5.6 Specifications of transport conditions 9 5.7 System tests and commissioning procedures 9 5.8 Operational conditions, guarantees 10 5.9 Documentation (under consideration) 10 Figure 1 Block diagram of the data flow (example) 10 Publication(s) referred to I
9、nside back coverBS7404-1.2:1991 ii BSI 08-1999 National foreword This Section of BS7404has been prepared under the direction of the Power Electrical Engineering Standards Policy Committee and is identical with IEC Publication870-1-2:1989 “Telecontrol equipment and systems Part1:General Consideration
10、s Section2: Guide for specifications”, published by the International Electrotechnical Commission (IEC). The International Standard does not give any relation between this Section of the standard and the other published and envisaged Parts and Sections. Other Parts and Sections of this British Stand
11、ard are as follows. Part1: General considerations; Section1.1: General principles (In preparation); Section1.2: Guide for specifications; Section1.3: Glossary (Envisaged as future work); Section1.4: Basic aspects of telecontrol data transmission (In preparation); Part2: Operating conditions; Section
12、2.1: Environmental conditions and power supplies (In preparation); Section2.2: Electromagnetic compatibility and erosive and corrosive influences (Envisaged as future work); Part3: Interfaces (electrical characteristics) (In preparation); Part4: Performance requirements (In preparation); Part5: Tran
13、smission protocols; Section5.1: Transmission frame formats (Envisaged as future work); Section5.2: Transmission procedures (Envisaged as future work); Section5.3: Structure of application data (Envisaged as future work); Section5.4: Coding specifications of application data (Envisaged as future work
14、); Part6: Telecontrol protocols compatible with ISO and CCITT standards (Envisaged as future work). Cross-references The Technical Committee has reviewed the provisions of IEC495, IEC870-1-1, IEC870-2-1, IEC870-3, IEC870-4, IEC870-5, IEC870-6to which reference is made in the text, and has decided th
15、at they are acceptable for use in conjunction with this British Standard. There is no British Standard corresponding to IEC495. British Standards which relate to the IEC870series are currently in preparation or are envisaged as future work.BS7404-1.2:1991 BSI 08-1999 iii A British Standard does not
16、purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside fro
17、nt cover, pagesi to iv, pages1to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS7404-1.2:1991 BSI 08-1999 1 Introduction Planning
18、 of telecontrol systems and defining the specifications of a system and of its equipment are complex and demand a large amount of detailed information. There are not only application functions of the system to be defined but also the operational parameters, the local environmental conditions and the
19、 data transmission paths available as well as their characteristics. The interfaces between the components of the system and other equipment facilities such as power supply requirements shall also be specified. Many aspects of this field are covered by standards within the IEC870 series on telecontr
20、ol equipment andsystems but many decisions are still left to the engineers who have to plan a system and establish the specifications. 1 Scope This series of standards applies to telecontrol equipment and systems with coded bit serial data transmission for monitoring and control of geographically wi
21、despread processes. 2 Object This section presents guidelines but not standards for establishing specifications for telecontrol systemsand equipment following the other IEC standards on telecontrol systems and other relevant International Standards and recommendations such as CCITT recommendations.
22、It also facilitates the comparison of equipment of different manufacturers. The planning of telecontrol systems should be subdivided into clearly defined steps: The first step involves a consideration of the operational requirements of telecontrol systems (clause3 of this section). In the second ste
23、p, the conditions and limitations of the data transmission network are considered and the most suitable utilization is specified (clause4 of this section). Thirdly, the required facilities for the telecontrol equipment and other equipment of telecontrol systems are specified. This includes considera
24、tions of whether it is useful to include existing local control equipment (clause5 of this section). The guidelines given in this section are applicable also if only parts of telecontrol systems are needed. In this case only the relevant clauses need be considered. 3 Description of the telecontrol s
25、ystem and its functions Design aim of the system, for example: “Main (or regional) control system.” (name of the power company or of the region), or “District telecontrol system.” (name of the district itself or of the district control centre), or “Telecontrol system for power station.” (name of the
26、 controlled station). 3.1 Description of the telecontrolled (or telemonitored) process 3.1.1 Purpose of process to be controlled (Short explanation only as far as necessary for planning telecontrol systems.) 3.1.2 Name of master stations and control centres Description of the function, e.g.dispatchi
27、ng centre, regional control centre, etc. 3.1.3 Number and names of outstations Description of their functions, e.g.“Power station.”, “Transformer station.”, etc. 3.1.4 Geographical configuration of the system System block diagram and site description. 3.1.5 Location and distances between interconnec
28、ted stationsBS7404-1.2:1991 2 BSI 08-1999 3.2 Functions of telecontrol systems 3.2.1 Survey of application functions 3.2.1.1 Basic functions Telemetering of the transfer power flow, generated power, summation of the power consumption, linevoltage, frequency, temperature, water-levels, etc.; telecoun
29、ting of the generated energy, energy consumption, energy transfer, etc.; teleindication of the circuit-breaker, protection functions, alarms, etc.; telecommand of the circuit-breaker, etc.; time synchronization between outstations and master station; time tagging of information. 3.2.1.2 Extended pro
30、cessing functions Teleregulation of the generated power (manually or automatically controlled); automatic power/frequency regulation; state estimation; automatic load shedding; switching programmes; operator interface (such as system operation, information display); information logging and reporting
31、; data storage (short term/long term); etc. 3.2.2 Requirements for operational parameters The following operational parameters are specified within Publication870-4: reliability; availability; maintainability; security; data integrity; time parameters; accuracy. In specifying the time parameters, pa
32、rticular consideration should be given to the: overall transfer time (sum of the times taken by the information passing through the individualsections of telecontrol systems, but also influenced by the network configuration, priority,accumulationof events, etc.); parameters for state information, su
33、ch as separating capability, time resolution, suppressiontime,etc.; updating time for measured values and set point commands; etc. It should be emphasized that in specifying the above-mentioned parameters the requirements of the process should be considered.BS7404-1.2:1991 BSI 08-1999 3 3.2.3 Detail
34、ed specification The facilities required should be listed and briefly described. Below is a list of the standard facilities found in telecontrol systems. 3.2.3.1 Input and acquisition of monitored information Single point information; for alarms, state information, faulty state information, etc. (fl
35、eeting information or persistent information); double point information with or without acquisition of the intermediate state for circuit-breakers, isolators, etc.; integrated values for telecounting of energy values, etc.; incremental information for flow values, etc.; measured values (analog or di
36、gital) with cyclic or periodic transmission or transmission on demand for telemetering of electric values, hydraulic values, etc.; time tagging requirements; group alarms or common alarms derived from digital or analog information; information related to the telecontrol system itself, e.g.transmissi
37、on error alarms, equipment failurealarms, etc.; other types of information. 3.2.3.2 Output and presentation of information State information; double point information with or without indicating the intermediate state; alarms, group alarms, common alarms; pulse output or persistent indication of inte
38、grated values; analog or digital display or measured values; information logging; data storage functions. 3.2.3.3 Command input Switching commands, single commands to change the state of an operational equipment in one direction (pulse commands or persistent commands); switching commands, double com
39、mands for circuit-breakers, isolators, etc. (pulse commands or maintained commands); set point commands values which are transmitted to the controlled equipment; adjusting commands for changing the state of operational equipment having more than two states; regulating commands (analog or digital) fo
40、r closed loop telemonitoring and telecommand (regulating step commands or persistent regulating commands); select and execute commands;BS7404-1.2:1991 4 BSI 08-1999 instruction commands for indicating a standard instruction to operators in the control room of a manually operated remote station, e.g.
41、“Start generators”; command sequences; group commands addressed to several items of equipment at an outstation; broadcast commands addressed to operational equipment at several or all outstations of a telecontrol system; commands related to the telecontrol system itself; interrogation commands; chec
42、k commands e.g.for the purpose of ensuring that the telecontrol equipment is functioning correctly; other types of information. 3.2.3.4 Command output Single commands; double commands with or without supervision of faulty states; set point commands with or without validity indication and with or wit
43、hout storage; adjusting commands; command sequences; indication of the instruction commands. 3.3 Data quantities The data quantities can be expressed by the number of input and output points. The number of points can be given in lists or tables, drawn up to reflect functions required as well as the
44、different locations of telecontrol systems, for example: Information input Input Station a b . n Totals Single point information Double point information . . . . Other types of informationBS7404-1.2:1991 BSI 08-1999 5 Information output (per station) NOTEInitial and maximum capacities should be incl
45、uded where they are not the same. Command input Command output (per station) NOTEInitial and maximum capacities should be included where they are not the same. Output Presentation Mimic diagram Digital display Analog display . Logging State information Double point information (with intermediate sta
46、te) . . . . Measured values Input Station a b . n Totals Single commands (pulse) Single commands (persistent) . . . . Other types of information Output Output mode Pulse output Persistent output . Analog output Single commands Double commands (withcheck) . . . . Check commandsBS7404-1.2:1991 6 BSI 0
47、8-1999 3.4 Man-machine interface The man-machine interface provides operators and maintenance personnel with appropriate reliable information on the actual status of the monitored process and the telecontrol system itself and offers facilities to control the process. Below is a list of facilities of
48、 the man-machine interface: mimic diagram; operators console; indicating instruments; visual display unit; recording equipment; acoustic indication; maintenance equipment. 3.5 Characteristics of the data flow 3.5.1 Block diagram of the data flow A block diagram should show the types and quantities o
49、f information transmitted in the telecontrol system(seeFigure 1). 3.5.2 Normal and disturbed conditions of the data flow 3.5.2.1 Order of the data flow with respect to disturbances within the process system a) Normal conditions (with a low rate of events per time unit). b) Avalanche conditions (large number of events in one or more outstations). 3.5.2.2 Changes of the data flow due to
