General protective data (36<67(0'$7$) includes settings associated with all functions rather than a specific protective or monitoring function. In contrast to the 36<67(0'$7$ as discussed in Sub-section 6.1.1, these settings can be changed over with the setting groups. To modify these settings, the user should select 6(7
7,1*6 menu option *URXS$ (setting group A), and then 36\VWHP'DWD. The other setting groups are *URXS%*URXS&, and *URXS', as described in Subsection 6.1.2.
Note:
All setting values in the setting group being restored to factory settings will be over-written. An inadvertent reset operation can be reversed by closing and reopening the DIGSI®4 session without saving changes.
Addr. Setting Setting options Default Setting Comment
301 ACTIVE GROUP Group A Group B Group C Group D
Parameter group A Active is
302 CHANGE to Group A
Group B Group C Group D Binary input Via protocol
Parameter group A Activation
F # LCD-Text Comment
7 >Set Group Bit0 >Parameter group selection (Select Bit 0) 8 >Set Group Bit1 >Parameter group selection (Select Bit 1)
Definition of nomi-nal rated values
At addresses 935,0$5<23 and ,35,0$5<23, the nominal volt-age (phase-to-phase) and current (phase) of the protected equipment is entered (e.g., motors). These values do not effect pickup settings. They are generally used to show values in reference to full scale. For example, if a CT ratio of 600/5 is selected and the full load current of a motor is 550 amps, a value of 550 amps should be entered for 35,0$5<23(5$7,1*&855(17 if monitoring in reference to full load current is de-sired. 550 amps are now displayed as 100 % in the percentage metering display.
(Subsection 6.1.1).
Ground Impedance Ratios (only for fault location)
The ground impedance ratios must be entered to facilitate line fault location. At ad-dress 5*5/5DWLR, the resistance ratio of the line is entered, and at address
;*;/5DWLR, the reactance ratio of the line is entered. The ground impedance ratios are calculated separately, and do not correspond to the real and imaginary com-ponents of Z0/Z1. Therefore, no complex calculations are necessary. The ground im-pedance ratios are obtained from conductor data using the following formulas:
Resistance Ratio: Reactance Ratio:
Where
R0 = Zero sequence resistance of the line X0 = Zero sequence reactance of the line R1 = Positive sequence resistance of the line X1 = Positive sequence reactance of the line
The ground impedance ratios may be calculated using the impedance values for the entire line or the impedance per mile values associated with the conductor, since the length of the line is factored out in the formulas above.
Calculation example:
20 kV free line 120 mm2 with the following data:
R1/s = 0.39 Ω/mile
X1/s = 0.55 Ω/mile Positive sequence impedance R0/s = 1.42 Ω/mile
X0/s = 2.03 Ω/mile Zero sequence impedance
For ground impedance ratios, the following emerge:
These values are set at addresses and respectively.
RG
The reactance value is entered as a secondary value at address in ohms per mile if address is set to Miles, or at address in ohms per kilometer if ad-dress is set to Kilometers (see Subsection 6.1.1 under “Units of Length”). If the setting of address is modified after entry of a reactance value at address
or , the reactance value must be modified and reentered accordingly.
The calculation of primary ohms in terms of secondary ohms is accomplished using the following formula:
Because the reactance value must be entered in secondary ohms per unit length, the formula above must be used to convert primary ohms per unit length into secondary ohms per unit length as shown below:
Example calculation:
The same example used to illustrate calculation of ground impedance ratios will be used to illustrate calculation of the reactance setting, with the following additional data on the current transformers and voltage transformers:
Current transformer 500 A / 5 A Voltage transformer 20 kV / 0.1 kV
The secondary reactance value is calculated as follows:
This value is entered at Address .
Recognition of Running Condition (only for motors)
Address ,0272567$57, is used for motor protection applications and corre-sponds to the minimum starting current of the protected motor. The current setting en-tered at address enables the device to determine if the protected motor is in start-up mode, thus allowing the device to properly perform the start-up time monitor-ing and overload protection functions.
In determining the setting for address , the following should be considered:
• A setting must be selected that is lower than the actual motor start-up current under all load and voltage conditions.
Zsecon dary Current-Transformer-Ratio Voltage-Transformer - Ratio
NCTR = Current transformer ratio NVTR = Voltage transformer ratio
X’sec NC TR
• Because the thermal cure of the overload protection is “frozen” (held constant) dur-ing motor start-up, the settdur-ing must be high enough to allow operation of the over-load protection at higher over-load current levels.
6.1.3.1 Settings
In the list below, the setting ranges and default setting values are for a device with a nominal current rating IN = 5 A. Consider the current transformer ratios when setting the device with primary values
For a nominal current rating IN = 1 A:
− For the pickup current (I MOTOR START) , divide the Setting Options values and default setting values by 5.
− For the Ground resistance and reactance ratios, multiply Setting Range and Setting Increments by 5!
1) depending of the ordering code
6.1.3.2 Information
Addr. Setting Setting Options Default Setting Comments
1101 V PRIMARY OP. 0.10 ~ 400.00 kV 12.00 kV Nominal operating voltage of primary equipment
1102 I PRIMARY OP. 10 ~ 50,000 A 100 A Nominal operating current of primary equipment
1103 RG/RL Ratio 0.33 ~ 7.00 1.00 Ground resistance ratio
1104 XG/XL Ratio 0.33 ~ 7.00 1.00 Ground reactance ratio
1105 x’ 0.002 ~ 2.000 Ω/mile1) 0.200 Ω/mile1) Line reactance value in secondary ohms
1106 x’ 0.001 ~ 1.243 Ω/km1) 0.124 Ω/km1) Line reactance value in secondary ohms
1107 I MOTOR START 3.00 ~ 50.00 A 12.50 A1) Motor start-up current
F# LCD-Text Comment
533 IA = Primary interrupted current Phase A
534 IB = Primary interrupted current Phase B
535 IC = Primary interrupted current Phase C
501 Device Pickup Pickup (protection)
511 Device Trip device trip (general)
126 Prot ON/OFF Protection On/Off (IEC60870-5-103)
561 Man.Clos.Detect Manual Close Detection (Impulse)
356 > Manual Close Manual Close