41
current equals to the difference of the current from two sides, both sides of the current phase
difference is 0 degree.
(4) When doing the test by three-phase current, if compensating current does not be
included, test results will also be incorrect. Since the three-phase current can only do
split-phase differential test, and the connecting mode of the transformer is different, both
sides of the current will produce a certain phase difference, thereby the protective device
must be done phase compensation in the software. So when we do a phase differential test,
the differential of the other phase will early act to plus a compensating current in order to let
this phase do not act. The test results will be correct.
Section 8 Impedance Characteristic
This procedure is used to test the phase characteristic of impedance relay. Applicable to
the boundary search test for the circle features, polygon, up throwing circle, under throwing
circle characteristic impedance relay.
1. [Scan center]
Summary of Contents for HT-802
Page 78: ...78...
