ABB Relion 650 Series Technical Manual page 98

Hide thumbs Also See for Relion 650 Series:

Table of Contents

Impedance protection

Load encroachment

Each of the six measuring loops has its own load encroachment characteristic based on the

corresponding loop impedance. The load encroachment functionality is always active, but can be

switched off by selecting a high setting.

The outline of the characteristic is presented in figure 45. As illustrated, the resistive blinders are

set individually in forward and reverse direction while the angle of the sector is the same in all four

ANSI05000196 V1 EN-US

Figure 45: Characteristic of load encroachment function

The influence of load encroachment function on the operation characteristic is dependent on the

chosen operation mode of FDPSPDIS (21) function. When output signal STCNDZI is selected, the

characteristic for FDPSPDIS (21) (and also zone measurement depending on settings) will be

reduced by the load encroachment characteristic (see figure 46, left illustration).

When output signal DLECND is selected, the operation characteristic will be as the right

illustration in figure 46. The reach will in this case be limit by the minimum operation current and

the distance measuring zones.

en05000196_ansi.vsd

1MRK 506 326-UUS B

M13140-86 v5

Line distance protection REL650

Technical manual