X
R
Load angle1
Load angle2
Load angle1
Load angle2
Outer X1
Inner R1
-Outer X1 reverse
Inner X1
Outer R1
-Inner X1 reverse
Outer Fw Ld
Ris Rch
Outer Rv Ld
Ris Rch
Inner Fw Ld
Ris Rch
Inner Rv Ld Ris Rch
Figure 586: Mho operation characteristics
The reach of inner circle is defined by the settings
Inner R1, Inner X1, Inner X1
reverse. Angle defined by settings Inner R1 and Inner X1 defines also reverse zone
angle. The reach of outer circle is defined by the settings
Outer R1, Outer X1, Outer
X1 reverse. Angle defined by settings Outer R1 and Outer X1 defines also reserve
zone angle.
The
PSB
and
SWING_ST
outputs can be blocked by activating
BLOCK
input. Blocking
also resets internal timers and impedance calculation.
4.7.6.6
Application
Describe different application possibilities of the function. The application
information answers one or more of the following questions:
• The problem of the application
• The purpose of the function
• Solution for the problem in general level
• Where can the function be used?
• When can the function be used?
• The application information shall NOT describe what the user should consider
or should calculate, plan, dimension etc. to make the function work in the
applications.
Power swing detection functions detect power swing conditions by using the fact
that the voltage/current variation during a power swing is slow compared to the
step change during a fault. Both faults and power swings may cause the positive
sequence impedance to enter into the operating characteristic of a distance relay
Protection functions
1MRS759142 F
1050
REX640
Technical Manual