⎯
19
⎯
6 F 2 S 0 8 4 6
Va = V1 + V2 + V0
=
Z1(Ia + (Z0
−
Z1)/Z1
×
I0 + Z0m/Z1
×
I0m) ......(2-11)
Where, Ia is the current at phase "a" relay point and is defined in the following equation by the
symmetrical component of the current:
Ia = I1 + I2 + I0..............................................................(2-12)
Here, defining the current synthesized by the phase "a" relay as Ia', and
Ia' = Ia + (Z0
−
Z1)/Z1
×
I0 + Z0m/Z1
×
I0m................(2-13)
then equation (2-11) can be rewritten as the following equation:
Va = Z1
×
Ia'...................................................................(2-14)
That is, positive-sequence impedance Z1 up to the fault point can be obtained from the simple ratio
of phase "a" voltage Va to compensated current Ia' according to equation (2-14).
Obtaining the compensated current according to equation (2-13) is called "zero-sequence
compensation." Note in this zero-sequence compensation, the compensation coefficient (Z0
−
Z1)/Z1 and Z0m/Z1 are not real numbers, but complex numbers. The GRZ100 relay has a
configuration that allows this compensation coefficient to be set as a complex number and setting
the coefficient correctly makes it possible to measure exactly the distance up to the fault point.
In equations (2-7) to (2-9), the fault resistance was ignored. Since the measurement of the distance
up to the fault point based on equation (2-14) is carried out using the reactance component, in
principle there is no influence on the voltage component due to the fault resistance. However,
under real operating conditions, distance measurement errors are produced as a result of the fault
resistance combined with the power flow or the current flowing into the fault point from the point
opposite the relay location.
Figure 2.2.2.2 Equivalent Circuit of Single-Phase Earth Fault
V1
V1F
V0F
V2F
Z1
I1
V2
I2
V0
I0
Z1
Z0
Negative-sequence circuit
Zero-sequence circuit
Positive-sequence circuit
Содержание GRZ100 B Series
Страница 264: ... 263 6 F 2 S 0 8 4 6 Appendix A Block Diagram ...
Страница 271: ... 270 6 F 2 S 0 8 4 6 ...
Страница 272: ... 271 6 F 2 S 0 8 4 6 Appendix B Signal List ...
Страница 307: ... 306 6 F 2 S 0 8 4 6 ...
Страница 308: ... 307 6 F 2 S 0 8 4 6 Appendix C Variable Timer List ...
Страница 310: ... 309 6 F 2 S 0 8 4 6 Appendix D Binary Input Output Default Setting List ...
Страница 321: ... 320 6 F 2 S 0 8 4 6 ...
Страница 322: ... 321 6 F 2 S 0 8 4 6 Appendix E Details of Relay Menu and LCD Button Operation ...
Страница 331: ... 330 6 F 2 S 0 8 4 6 ...
Страница 340: ... 339 6 F 2 S 0 8 4 6 Appendix G Typical External Connections ...
Страница 377: ... 376 6 F 2 S 0 8 4 6 ...
Страница 384: ... 383 6 F 2 S 0 8 4 6 Appendix J Return Repair Form ...
Страница 388: ... 387 6 F 2 S 0 8 4 6 Customer Name Company Name Address Telephone No Facsimile No Signature ...
Страница 389: ... 388 6 F 2 S 0 8 4 6 ...
Страница 390: ... 389 6 F 2 S 0 8 4 6 Appendix K Technical Data ...
Страница 401: ... 400 6 F 2 S 0 8 4 6 ...
Страница 402: ... 401 6 F 2 S 0 8 4 6 Appendix L Symbols Used in Scheme Logic ...
Страница 405: ... 404 6 F 2 S 0 8 4 6 ...
Страница 406: ... 405 6 F 2 S 0 8 4 6 Appendix M Example of Setting Calculation ...
Страница 417: ... 416 6 F 2 S 0 8 4 6 ...
Страница 418: ... 417 6 F 2 S 0 8 4 6 Appendix N IEC60870 5 103 Interoperability and Troubleshooting ...
Страница 430: ... 429 6 F 2 S 0 8 4 6 Appendix O Programmable Reset Characteristics and Implementation of Thermal Model to IEC60255 8 ...
Страница 434: ... 433 6 F 2 S 0 8 4 6 Appendix P Inverse Time Characteristics ...
Страница 437: ... 436 6 F 2 S 0 8 4 6 ...
Страница 438: ... 437 6 F 2 S 0 8 4 6 Appendix Q Failed Module Tracing and Replacement ...
Страница 444: ... 443 6 F 2 S 0 8 4 6 Appendix R Ordering ...
Страница 447: ......