58
6
F
2
S
0
7
8
9
3.3 Automatic Supervision
3.3.1 Basic Concept of Supervision
Though the protection system is in a non-operating state under normal conditions, it is waiting
for a power system fault to occur at any time and must operate for the fault without fail.
Therefore, the automatic supervision function, which checks the health of the protection system
during normal operation by itself, plays an important role. The numerical relay based on the
microprocessor operations is suitable for implementing this automatic supervision function of
the protection system. The GRT100 implements the automatic supervision function taking
advantage of this feature based on the following concept:
The supervising function should not affect protection performance.
Perform supervision with no omissions wherever possible.
When a failure occurs, it should be able to easily identify the failure location.
Note
: Automatic supervision function includes automatic monitor function and automatic test
function. For the terminology, refer to IEC IEV 60448.
3.3.2 Relay Monitoring and Testing
The relay is supervised with the following items.
AC input imbalance monitoring
The AC current input is monitored such that the following equation is satisfied and the health of
the AC input circuit is checked.
Max(|I
a
|, |I
b
|, |I
c
|)
4
Min(|I
a
|, |I
b
|, |I
c
|)
k
0
where,
Max(|I
a
|, |I
b
|, |I
c
|) = Maximum amplitude among I
a
, I
b
and I
c
Min(|I
a
|, |I
b
|, |I
c
|) = Minimum amplitude among I
a
, I
b
and I
c
k
0
= 20% of rated current
A/D accuracy checking
An analogue reference voltage is transmitted to a prescribed channel in the analogue-to-digital
(A/D) converter, and it is checked that the data after A/D conversion is within a prescribed range
and that the A/D conversion characteristics are correct.
Memory monitoring
The memories are monitored as follows depending on the type of the memory and checked that
the memory circuits are healthy:
Random access memory monitoring:
Writes/reads prescribed data and checks the storage function.
Program memory monitoring: Checks the checksum value of the written data.
Setting value monitoring:
Checks discrepancy between the setting values stored in
duplicate.
Summary of Contents for GRT100 Series
Page 142: ... 141 6 F 2 S 0 7 8 9 Appendix A Block Diagram ...
Page 144: ... 143 6 F 2 S 0 7 8 9 Appendix B Signal List ...
Page 159: ... 158 6 F 2 S 0 7 8 9 ...
Page 160: ... 159 6 F 2 S 0 7 8 9 Appendix C Variable Timer List ...
Page 162: ... 161 6 F 2 S 0 7 8 9 Appendix D Binary Output Default Setting List ...
Page 165: ... 164 6 F 2 S 0 7 8 9 ...
Page 166: ... 165 6 F 2 S 0 7 8 9 Appendix E Details of Relay Menu and LCD and Button Operation ...
Page 174: ... 173 6 F 2 S 0 7 8 9 Appendix F Case Outline Flush Mount Type Rack Mount Type ...
Page 179: ... 178 6 F 2 S 0 7 8 9 ...
Page 180: ... 179 6 F 2 S 0 7 8 9 Appendix G External Connections ...
Page 185: ... 184 6 F 2 S 0 7 8 9 ...
Page 200: ... 199 6 F 2 S 0 7 8 9 ...
Page 201: ... 200 6 F 2 S 0 7 8 9 Appendix J Return Repair Form ...
Page 205: ... 204 6 F 2 S 0 7 8 9 Customer Name Company Name Address Telephone No Facsimile No Signature ...
Page 206: ... 205 6 F 2 S 0 7 8 9 ...
Page 207: ... 206 6 F 2 S 0 7 8 9 Appendix K Technical Data ...
Page 220: ... 219 6 F 2 S 0 7 8 9 ...
Page 221: ... 220 6 F 2 S 0 7 8 9 Appendix M Symbols Used in Scheme Logic ...
Page 224: ... 223 6 F 2 S 0 7 8 9 ...
Page 225: ... 224 6 F 2 S 0 7 8 9 Appendix N Implementation of Thermal Model to IEC60255 8 ...
Page 228: ... 227 6 F 2 S 0 7 8 9 ...
Page 229: ... 228 6 F 2 S 0 7 8 9 Appendix O IEC60870 5 103 Interoperability and Troubleshooting ...
Page 241: ... 240 6 F 2 S 0 7 8 9 Appendix P Modbus Interoperability ...
Page 255: ... 254 6 F 2 S 0 7 8 9 ...
Page 256: ... 255 6 F 2 S 0 7 8 9 Appendix Q Inverse Time Characteristics ...
Page 259: ... 258 6 F 2 S 0 7 8 9 ...
Page 260: ... 259 6 F 2 S 0 7 8 9 Appendix R Failed Module Tracing and Replacement ...
Page 266: ... 265 6 F 2 S 0 7 8 9 Appendix S Ordering ...
Page 269: ... 268 6 F 2 S 0 7 8 9 3 1 Oct 2 2017 Republished under spin off company ...
Page 270: ......