ABB RELION REX640 Technical Manual page 872

Protection and control

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Table of Contents

Protection functions

Table 813: Special conditions

U3P connected to real measurements

Improper analog channel configuration causes a validation error if the analog

channels are not completely configured or they do not match with certain settings.

For troubleshooting, check the contents of this chapter and also the preprocessing

blocks in this document. The configuration can be written to the protection relay

once the mismatch is corrected.

Operation principle

The function can be enabled and disabled with the

corresponding parameter values are "On" and "Off".

The operation of PSPTOV can be described with a module diagram. All the modules

in the diagram are explained in the next sections.

Figure 489: Functional module diagram

Level detector

The calculated positive-sequence voltage is compared to the set

If the value exceeds the set

Relative hysteresis setting can be used for preventing unnecessary oscillations if the

input signal slightly varies from the

area, the start condition has to be fulfilled again and it is not sufficient for the

signal to only return to the hysteresis area.

Once activated, Timer activates the START output. The time characteristic is

according to DT. When the operation timer has reached the value set by

delay time , the OPERATE output is activated if the overvoltage condition persists.

If the positive-sequence voltage normalizes before the module operates, the reset

timer is activated. If the reset timer reaches the value set by

operate timer resets and the START output is deactivated.

The function can work with any two voltage

channels connected but it is recommended

to connect all three voltage channels.

Start value , the level detector enables the timer. The

Start value setting. After leaving the hysteresis

1MRS759142 F

Operation setting. The

Start value setting.

Reset delay time , the

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