Siemens 7SA511 Polygonal Impedance Fault Detection, Exist Impedance Zone, Prog. Za, RA1 RA2 RAE

7SA511 Line Protection RelayChapter 5

5.10.6 Polygonal Impedance Fault Detection

This section applies only for relays programmed for polygonal impedance fault detection at address 7802 (see section 5.6). Skip this section if overcurrent fault detection or voltage controlled fault detection is being used.

Table 5-15 lists the presettings, the optional settings and the setting ranges available for polygonal impedance fault detection. Compare these presettings to the information on the completed worksheets and determine which settings you need to change to match your operating environment. When you have changed all the necessary settings, follow the procedure described in section 5.3.4 to save the new settings.

Prerequisite Settings:

Addr.	LCD Text
7801	DIST. PROT.
7802	DIST. F. DET.

Description

Distance protection function

Type of fault detection

Setting

EXIST IMPEDANCE ZONE

Table 5-15.Polygonal Impedance Fault Detection Settings.

Addr.

1503

1601

1602

1621

1622

1623

1624

1625

1626

LCD Text

PROG. ZA

Iph>>

Ie>

Iph>

X+A

X-A

RA1

RA2

RAE

Description

Measurement controls used when the relay is programmed for polygonal impedance fault detection

Overcurrent detection threshold value for phase currents

Overcurrent detection threshold value for ground currents

Minimum current for polygonal impedance detection

Reactance intersection (reach) forwards

Reactance intersection (reach) reverse

Resistance intersection for phase-to-phase characteristic;

phase angle below 45 (load area)

Resistance intersection for phase-to-phase characteristic;

phase angle above 45￿(fault area)

Resistance intersection for phase-to-ground characteristic

Preset

LE:Zphe/LL:Zphph

1.80I/In

0.50I/In

0.20I/In

12.00

2.50

6.00

6.00

12.00

Options/Range

LE:Zphe/LL:I>>

0.25- 4.00 I/In

0.10- 1.00 I/In

0.10- 4.00 I/In

0.10- 200.00

0.10- 200.00

0.10- 100.00

0.10- 200.00

0.10- 200.00 W

July 27, 1995 5-31