2. Changing of minimal voltage protection parameters actuation (3Hmin)

Work order of 3Hmin:

Actuation of 3Hmin happens when voltage on all 3 phases А, В, С becomes less than voltage installed.

Set on the console voltage of 20 V by phases В and С and 50 V by phase A. Smoothly decrease voltage Ua on the console till drawdown 3Hmin (drawdown control 3nmin is held at lightening of light-emitting diode D5 on the MP3C-05). Fix on the ЖКИ MP3C-05 in menu CHANGES value of voltage protection actuation Ucp. Calculate according to the formula accuracy of voltage protection actuation:

Set the voltage of 50 V on the console on phases В and C. Increase Ua till switching off of the LED D5. Fix on ЖКИ MP3C-05 in menu MEASUREMENTS value - voltage of reverse protection in initial state U_B.

Calculate according to the formula coefficient of reverse voltage:

Make similar changes, changing voltages of phases В and C.

Check parameters of 3Hmin for restraints by voltage 60 V and 100 V by mentioned above principle.

Put measurements and calculation data into table 4.

Table 4

№ п/ П	Protectio n type	Voltage phase	Uy (V)	Ucp (V)	UB (V)	К*,	s(!, %
1	Знтт	А	30
2	Знтт	А	60
3	Знтт	А	100
4	Знтт	В	30
5	Знтт	В	60
6	Знтт	В	100
7	Знтт	С	30
8	Знтт	С	60
9	Знтт	С	100

Compare К_ни , S_u with allowable meanings from table 1

5. Contents of report

1. Cover page with laboratory work title.

2. Description of the process of diagnostics of MP3C-05 parameters.

3. Work results data table.

4. Conclusions.

NATIONAL AVIATION UNIVERSITY INSTITUTE OF AIRSPACE CONTROL SYSTEMS THE DEPARTMENT OF COMPUTER -AIDED INTEGRATED COMPLEXES