BS 7494-2:1993

Committees responsible
National foreword
Section 1. General
1.1 Scope and object
1.2 Normative references
1.3 Service conditions
1.4 Telecommunication system used
Section 2. Terminology
Section 3. Characteristic of analogue comparison tele-
protection schemes
3.1 Arrangement of teleprotection schemes and their
      associated interfaces
3.2 Teleprotection operating time (TA or To)
3.3 Protection operating time (TB or Tp)
Section 4. Requirements
4.1 General equipment interface requirements
4.2 Specific power supply requirements
4.3 Operational requirements
Section 5. Methods for performance testing
5.1 General equipment interface tests
5.2 Specific power supply tests
5.3 Teleprotection system performance tests
5.4 Checking alarm functions
Annexes
A. (informative) Types of analogue comparison
    protection systems and associated teleprotection
    schemes
B. (informative) The binary symmetric channel (BSC)
    model
C. (informative) Bibliography
Figures
1. Arrangement of analogue comparison protection
    system
2. Typical operating times for analogue comparison
    protection systems
3. Parameters for overall teleprotection channel tests
    and recommended setting values of the protection
4. Estimated examples of probability of missing command
    versus signal-to-noise for a typical phase
    comparison protection
5. Test set-up for dependability measurement analogue
    teleprotection channel
6. Test set-up for security measurement (analogue
    teleprotection channel)
7. Test set-up for dependability measurement (digital
    teleprotection channel)
8. Test set-up for security measurement (digital tele-
    protection channel)
9. Estimated example of probability of unwanted
    commands versus signal-to-noise for a typical phase
    comparison protection
10. Estimated example of probability of unwanted
    commands versus BER for a typical current
    differential protection on a digital teleprotection
    channel
A.1 General view of analogue schemes

Gives narrowband and wideband teleprotection systems used to convey analogue information about the primary quantities such as phase or phase and amplitude. The teleprotection equipment can either be separate or integrated in one unit with the protection equipment or the telecommunication equipment.

This part of IEC 834 applies to narrowband and wideband teleprotection systems used to convey analogue information about the primary quantities such as phase or phase and amplitude. The teleprotection equipment can either be separate or integrated in one unit with the protection equipment or the telecommunication equipment.

Narrow-band systems include systems operating within a 4 kHz band (for each direction of transmission).

Wide-band systems include systems occupying more than 4 kHz bandwidth (for each direction of transmission).

Broad-band command systems are not dealt with in this standard.

The object of this part of IEC 834 is to establish performance requirements and recommended testing methods for analogue comparison teleprotection equipments used in connection with power network protection systems and to define the associated terminology. The information conveyed and compared such as phase or phase and amplitude quantities can be in analogue or digital form.

In addition to the power supply and the interfaces belonging to the teleprotection equipment, the performance of the teleprotection equipment in conjunction with the protection equipment shall be tested.

All the tests should be considered as type tests [see IEC 50(151)].