Measurement Principle - ABB Relion Technical Manual

Generator protection

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1MRK 502 048-UUS A

Technical manual

adding the input phase voltages. 3V

directly from a voltage transformer in the neutral of a power transformer, or from a

secondary broken delta connection of a transformer with a wye-grounded primary.

ROV2PTOV (59N) has two steps with separate time delays. If the ground overvoltage

remains above the set value for a time period corresponding to the chosen time delay, the

corresponding TRIP signal is issued.

The time delay characteristic is setable for step 1 and can be either definite or inverse time

delayed. Step 2 is always definite time delayed.

The voltage related settings are made in percent of the global phase-to-phase base voltage

divided by √3.

Measurement principle

The residual voltage is measured continuously, and compared with the set values, Pickup1

and Pickup2.

To avoid oscillations of the output PICKUP signal, a hysteresis has been included.

It is possible to block two step residual overvoltage protection (ROV2PTOV, 59N)

partially or completely, by binary input signals where:

The voltage measuring elements continuously measure the residual voltage. Recursive

Fourier filters filter the input voltage signal. The single input voltage is compared to the

set value, and is also used for the inverse time characteristic integration. The design of

Two step residual overvoltage protection (ROV2PTOV, 59N) is schematically described

may also be input single phase by either measuring

blocks all outputs

blocks all pickupand trip outputs related to step 1

blocks all pickup and trip inputs related to step 2

Voltage protection

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650 series Reg650 ansi