1MAC309294-MB F Section 4
Protection functions
RER620 189
Technical Manual
4.3.1.2 Function block
Figure 85: Function block
4.3.1.3 Functionality
The single-phase overvoltage protection 59 is applied on power system elements, such as
generators, transformers, motors and power lines, to protect the system from excessive
voltages that could damage the insulation and cause insulation breakdown. The
three-phase overvoltage function includes a settable value for the detection of overvoltage
either in a single phase, two phases or three phases.
59 includes both definite time (DT) and inverse definite minimum time (IDMT)
characteristics for the delay of the trip.
The function contains a blocking functionality. It is possible to block function outputs,
timer or the function itself, if desired.
4.3.1.4 Operation principle
The function can be enabled and disabled with the Operation setting. The corresponding
parameter values are Enable and Disable.
The operation of the single-phase overvoltage protection can be described by using a
module diagram. All the modules in the diagram are explained in the next sections.
V_B_BC
BLOCK
OPERATE
START
59
V_A_AB
V_C_CA
OPR_A_AB
OPR_B_BC
OPR_C_CA
ST_A_AB
ST_B_BC
ST_C_CA
To Next Page
Loading...
