SEL-400G Advanced Generator Protection System

SEL-400G Advanced Generator Protection System

Advanced Generator Protection System

Key Features and Benefits

The SEL-400G Advanced Generator Protection System offers unsurpassed protection, integration, control, and monitor

ing features for all types of generators including hydro, pumped-storage hydro, large steam turbines, and combustion gas

turbines (CGTs).

➤ Protect generators and step-up transformers in a single device with two independent universal differential zones.

➤ Provide protection during generator startup with two independent frequency zones with frequency tracking from

5 Hz to 120 Hz.

➤ Increase machine life with advanced generator monitoring capabilities such as turn-to-turn fault detection to detect

faults and abnormal conditions before they cause permanent damage.

➤ Reduce complexity for pumped storage generation with internal relay logic that eliminates the need for external

switching.

➤ Implement comprehensive protection schemes for generator and auxiliary systems with 18 current and 6 voltage

inputs.

➤ Design, deploy, and commission relay settings with ease using SEL Grid Configurator

Features

➤Current and Voltage Inputs. With 18 CT inputs

and 6 PT inputs, the SEL-400G provides protection

for generators ranging in size from small to large,

and protection schemes ranging from simple to

complex.

➤Universal Differential Protection (87Z). The

SEL-400G supports two independent universal

differential elements that can provide fast, sensitive,

and secure protection for as many as two independent

protection zones.

➤Stator Winding Ground Fault Protection (64G/

64S). The SEL-400G offers passive and active

methods for detecting ground faults across 100 percent

of the stator winding without sacrificing security.

➤Field Winding Ground Fault Protection (64F).

The SEL-400G, when used in conjunction with the

SEL-2664 Field Ground Module, can provide field

winding ground fault protection. The element can

be configured to provide either an alarm or trip

functions for the first field winding to ground fault.

Restricted Earth fault Protection (REF). The

SEL-400G provides three REF elements that can

provide fast, sensitive, and secure ground fault

protection for a low impedance-grounded

generator or for the wye winding of a generator

step-up (GSU).

➤ Stator Winding Turn-to-Turn Fault Protection

(60P/60N). The SEL-400G provides two sensitive

split-phase protection elements that can turn-to

turn fault protection for multibranch hydro

machines. The elements can adapt to standing

current offset and secure for external faults.

➤ Pumped Storage Logic. The SEL-400G internally

corrects the phasing introduced by the reversing

switch.

➤ Extended Range Frequency Tracking of 5–120 Hz.

The SEL-400G wide-range frequency tracking

algorithm ensures that all protection functions are

secure and dependable regardless of the frequency.

The SEL-400G also independently tracks the

generator and system frequencies.

➤ Loss-of-Field Protection (40). The SEL-400G

offers two impedance-based loss-of-field (LOF)

schemes and a generator capability-based LOF

scheme to protect the generator during a LOF event.

➤ Current Unbalance Protection (46). The SEL-400G

provides two negative-sequence overcurrent

elements for generator current unbalance protection.

Each element provides two levels, one definite and

one inverse-time. Each element can be configured

to operate on fundamental or harmonic negative

sequence current.

➤ Overexcitation Protection (24). The SEL-400G

provides two volts-per-hertz elements that can

provide overexcitation protection for both

generator and GSU. Each element provides two

levels of definite-time and two user-defined inverse

time curves.

➤ Inadvertent Energization Protection (INAD).

The SEL-400G provides as many as four inadvertent

energization elements that arm themselves when

the generator is taken offline and protect the

generator from inadvertent energization.

➤ Directional Power Protection (32). The SEL-400G

provides four sensitive directional power elements

with independent time delays. Additionally, the

SEL-400G provides a biased characteristic that

ensures both security and dependability.

➤ Out-of-Step Protection (78). The SEL-400G

provides two out-of-step (OOS) protection schemes:

single or double blinder. The SEL-400G also

includes a pole slip counter (PSC) that counts the

number of pole slips a generator experienced

during an OOS condition.

➤ Over- and Underfrequency Protection (81). The

SEL-400G provides six levels of over- or

underfrequency protection with undervoltage

supervision. The protection can be configured for

two independent frequency zones (generator and

power system zone).

➤ Rate-of-Change-of-Frequency Protection (81R).

The SEL-400G provides six levels of over- or

under-rate-of change-of-frequency protection with

undervoltage supervision. The protection can be

configured for two independent frequency zones

(generator and power system zone).

➤ Frequency Accumulation Protection (81A). The

SEL-400G provides frequency accumulation

protection by measuring the time-of-operation in

as many as eight frequency bands. The relay also

supports continuous bands.

➤ Thermal Overload Protection (49). The SEL-400G

provides three independent general-purpose thermal