HVTest HT-802, Руководство пользователя

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Section 18 Frequency Variation Test
The program respectively simulates U-phase, V-phase, W-phase single-phase ground
transient fault and uv, vw, wu phase to phase transient failure. Simulated fault current is a
fixed current; simulated pre-fault voltage is rated voltage 57.73V; simulated failure time is
generally 100-150ms. When single-phase ground fault occurs, short-circuit voltage V = (1 + K)
I × ZD + (1-1.05m) × Un. When phase-to-phase short circuits, fault voltage U = 2 × I × ZD +
(1-1.05m) × 3 Un, in which m is the coefficient, its value are 0.9 and 1.2. For the
microcomputer protection, when m = 0.9, D + + outgate (direction element outgate); when m
= 1.2, DZ, D + + should export. DZ is variation distance export, when DZ first act, put into the
main protection and zero-sequence protection, and other protection should exit.
1. ZD - power frequency variation distance protection setting value
Power frequency variation distance protection, the protection should be act reliably when
M=1 . 2 times; the protection does not act reliably when M=0 . 9 times.
3. The connecting mode, as shown in the following illustration.