The SEL-700G Relay is the right solution for utility and industrial generator protection, with an autosynchronizer, flexible I/O, and advanced communications. Apply the SEL-700G Relay for comprehensive primary and backup generator protection.
The SEL-700G provides a complete protection and synchronization solution for synchronous generators. Eliminate the complexity and cost of standalone synchronizer packages. Integrating the synchronization capability into the generator protection relay provides the most cost-effective and reliable solution.
Easily upgrade protection without cutting or drilling existing cutouts with a small form factor and multiple mounting adapters. Quickly integrate into serial- or Ethernet-based communications with Modbus®, DNP3, IEC 61850,MIRRORED BITS® communications, DeviceNet™, and other protocols.
Functional Overview
21C/
51VC
Compensator Distance, Voltage Restrained/Controlled Time-Overcurrent
24
Volts/Hertz
25G
Synchronism Check
27
Undervoltage
32
Directional Power
40
Loss-of-Field
46
Neg. Seq. Overcurrent
49R
Thermal Overload (RTD)
49T
Thermal Model
50N
Neutral Overcurrent
50
(P,G,Q) Overcurrent (Phase, Ground, Neg. Seq.)
51G
Ground Time-Overcurrent
51N
Neutral Time-Overcurrent
59N
(64G1) Neutral Overvoltage
59S
Synchronism Overvoltage
59
(P,G,Q) Overvoltage (Phase, Ground, Neg. Seq.)
60
Loss-of-Potential
64F
Field Ground
64G
100 Percent Stator Ground
67G
Directional Ground Overcurrent
67N
Directional Neutral Overcurrent
78
Out-of-Step
81
(O,U,R) Frequency (Over, Under, Rate)
87
Three-Phase Current Differential
87N
Neutral Current Differential
REF
Restricted Earth Fault
52PB
Pushbutton Trip/Close
85
SEL Mirrored Bits Communications
BF
Breaker Failure
BRM
Breaker Wear Monitor
DFR
Event Reports
ENV
SEL-2600
HMI
Operator Interface
LDP
Load Data Profiling
LGC
SELogic Control Equations
MET
High-Accuracy Metering
PMU
Synchrophasors
SER
Sequential Events Recorder
RTU
Remote Terminal Unit
Front- and Rear-Panel Diagrams
Front
Rear
Comprehensive Generator Protection
Connect the SEL-700G Generator Protection Relay across small, medium, or large generators forcomplete primary and backup protection. Adding the neutral voltage connection provides 100 percent stator ground protection, based on fundamental-frequency and third-harmonic neutral-voltage measurements. Connecting the neutral current input provides protection for solidly grounded or resistance-grounded machines.
Autosynchronizer
Replace external generator control and synchronizer relays with the built-in automatic synchronizer function. Frequency, voltage, and phase control of the generator are automatically synchro-nized and connected to the power system. Monitor the generator synchro-nization process using generator start reports and the PC-based synchroscope.
Current Differential Protection
Apply sensitive percentage-restrained current differential elements and an unrestrained element, along with synchronism check and volts-per-hertz elements, across the entire unit to protect both the generator and the step-up transformer. Optional current differential elements detect stator faults using a secure, sensitive current differ-ential function. Power transformer and CT connection compensation allows the unit step-up transformer to be included in the generator differential zone.
Breaker Wear Monitoring
Record accumulated breaker contact wear with the breaker monitor function, which uses the manufacturer’s speci-fications for defining breaker operation limits. The internal monitor tracks the total number of close/open operations and integrates the interrupted current per phase. Set an alarm to alert opera-tors when measured and accumulated quantities approach maintenance thresholds. This information facilitates proactive breaker maintenance and replacement without underutilizing resources.
Easy Communications
Choose from single or dual copper or fiber-optic Ethernet ports, or serial communications, and several protocols, including Mirrored Bits®communications and IEC 61850. Pick multiple Modbus® TCP or Modbus serial sessions for custom configuration of your application. Use DNP3 Serial or DNP3 LAN/WAN protocols.