Abstract
Due to the electromagnetic induction between transmission
lines and the associated grounding wires, power frequency
current causes flow into the ground network via the metallic tower,
which may interfere with grounding resistance measurements.
This paper analyzes the mechanisms of this interference, and
shows that power frequency interference becomes stronger at
phase-wire transposition towers. Grounding resistance measurement
by the variable frequency (VF) method has been proven to be
effective in dealing with power frequency interference. However,
the test equipment based on the VF method is always deactivated
when the external interference voltage exceeds a preset level
in order to avoid false readings. This paper aims at tackling
the problem by introducing a reverse phase cancellation (RPC)
method, which acquires and processes the interference signal
before generating a cancelling signal with the same amplitude
and frequency and a phase which is exactly opposite in polarity.
This paper proves that the RPC method represents an excellent
improvement over the VF method since it retains the advantages
of VF and avoids the trip-out of test equipment due to excessive
interference.
lines and the associated grounding wires, power frequency
current causes flow into the ground network via the metallic tower,
which may interfere with grounding resistance measurements.
This paper analyzes the mechanisms of this interference, and
shows that power frequency interference becomes stronger at
phase-wire transposition towers. Grounding resistance measurement
by the variable frequency (VF) method has been proven to be
effective in dealing with power frequency interference. However,
the test equipment based on the VF method is always deactivated
when the external interference voltage exceeds a preset level
in order to avoid false readings. This paper aims at tackling
the problem by introducing a reverse phase cancellation (RPC)
method, which acquires and processes the interference signal
before generating a cancelling signal with the same amplitude
and frequency and a phase which is exactly opposite in polarity.
This paper proves that the RPC method represents an excellent
improvement over the VF method since it retains the advantages
of VF and avoids the trip-out of test equipment due to excessive
interference.
Original language | English |
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Pages (from-to) | 1016-1023 |
Number of pages | 8 |
Journal | IEEE Transactions on Power Delivery |
Volume | 30 |
Issue number | 2 |
DOIs | |
Publication status | Published - 25 Nov 2014 |
Keywords
- grounding resistance measurement
- power frequency interference
- transmission tower