ABB RELION REX640 Technical Manual page 370

Protection and control

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Table of Contents

Protection functions

Table 415: 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 PHPVOC can be described by using a module diagram. All the

modules in the diagram are explained in the next sections.

Figure 221: Functional module diagram

Effective start value calculator

The normal starting current above which the overcurrent protection starts is set

to be changed during certain conditions like magnetizing inrush or when the

terminal voltages drop due to a fault. Hence, the effective start value calculator

module dynamically calculates the effective start value above which the overcurrent

protection starts.

Four methods of calculating the effective start value are provided in PHPVOC. These

can be chosen with the

control", "Volt & Input Ctrl" or "No Volt dependency".

The calculated effective start value per phase, EFF_ST_VAL_A, EFF_ST_VAL_B,

EFF_ST_VAL_C, is available in the Monitored data view and is used by the Level

detector module.

Start value setting. The Effective start value of the current may need

Control mode setting to be either "Voltage control", "Input

All three phase-to-phase voltages should be available for the function to

operate properly.

The function can work with any two phase

voltage channels connected but it is recom-

mended to connect all three voltage chan-

Operation setting. The

Technical Manual

1MRS759142 F