CHAPTER 9: THEORY OF OPERATION
OVERVIEW
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
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Figure 9-3: Stability angle
Sketches 4A, 4B, 4C, and 4D are for three-terminal lines and they correspond directly to 2A, 2B, 2C, and 2D. Note from the
Stability Angle figure that for a three-terminal line, the relay at A must receive information from both the remote terminals.
The same applies to the relays at terminals B and C. As in the case of the two-terminal lines, the integrator illustrated in the
next figure is actually set for 3 to 4 ms.
While all the sketches compare the positive half-cycle of current with a receiver output, the negative half-cycle might just
as well have been selected. However, if this were done, in Figure 2A for example, it would have been necessary to compare
the presence of negative current with a received SPACE signal rather than a MARK signal.
This discussion and the figures are rudimentary. The complete phase comparison scheme is considerably more
sophisticated and is discussed subsequently in more detail. However, at this point, note that phase comparison on a
continuous basis is not permitted mainly because it tends to reduce the security of the scheme. For this reason, fault
Содержание L60
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Страница 14: ...1 4 L60 LINE PHASE COMPARISON SYSTEM INSTRUCTION MANUAL FOR FURTHER ASSISTANCE CHAPTER 1 INTRODUCTION 1 ...
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Страница 590: ...5 382 L60 LINE PHASE COMPARISON SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 5 SETTINGS 5 ...
Страница 632: ...7 12 L60 LINE PHASE COMPARISON SYSTEM INSTRUCTION MANUAL TARGETS MENU CHAPTER 7 COMMANDS AND TARGETS 7 ...
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Страница 744: ...C 6 L60 LINE PHASE COMPARISON SYSTEM INSTRUCTION MANUAL COMMAND LINE INTERFACE APPENDIX C COMMAND LINE INTERFACE C ...
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