Voltage protection relay PCS-985GI

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Product overview
PCS-985GI is a numerical generator protection device integrating primary and backup protection functions in a single unit. It delivers comprehensive protection for power-plant generators and basic protection for generators and excitation transformers. PCS-985GI supports turbo-dynamo, gas-turbine, hydro and nuclear generators with multiple connection schemes.
PCS-985GI offers up to 56 analog input channels for current and voltage measurements. Protection functions are configurable to match application needs. Built-in ancillary features include fault diagnostics, disturbance and event recording, fault recorder and wide communication support.

Key miscellaneous functions

• Fault detector (FR)
• Voltage and current drift auto-adjustment
• VT circuit supervision (VTS)
• CT circuit supervision (CTS)
• CT saturation detection (CTS)
• Self-diagnostic
• GPS clock synchronization
• Fault recorder
• IEC61850 MMS & GOOSE for station bus
• IEC60870-5-103 protocol
• MODBUS protocol
• DNP 3.0 protocol

Basic protections

• Differential protection (87ET)
• Overcurrent protection (50/51P)

Generator protection functions

• Current differential protection (87G)
• Incomplete current differential protection (87IG)
• Phase-segregated transverse differential protection (87STG)
• Neutral-point transverse differential protection (87NTG)
• Generator inter-turn protection (59NIT)
• Stator overload protection (49S)
• Fundamental zero-sequence voltage stator ground fault protection (64S1)
• Zero-sequence overcurrent stator ground fault protection (64S)
• Generator 3rd harmonic stator ground fault protection (64S2)
• Stator ground fault protection with 20 Hz voltage injection (64SInj)
• Ping-Pang type rotor ground fault protection (64R)
• Rotor ground fault protection with low-frequency square-wave injection (64RInj)
• Rotor winding overload protection (49E)
• Inadvertent energization protection (50/27)
• Out-of-step protection (78)
• Startup and shutdown protection (StShut)
• Shaft overcurrent protection (51GS)
• Negative-sequence overload protection (46G)
• Reverse power protection (32R)
• Low forward power protection (32F)
• Overexcitation protection (24)
• Loss of excitation protection (40G)
• Phase overcurrent protection (50/51P)
• Phase overvoltage protection (59P)
• Undervoltage protection (27P)
• Overfrequency protection (81O)
• Underfrequency protection (81U)
• Impedance protection (21)
• Breaker failure protection (50BF)
• Mechanical protection (MR)
• Voltage balance protection (60)

Technical specifications

• Model: PCS-985GI
• Up to 56 analog input channels including current and voltage inputs
• Integrates main and backup protection in a single device
• Applicable to turbo-dynamo, gas-turbine, hydro and nuclear generators with different connection modes
• Configurable protection functions covering differential, overcurrent, ground-fault, rotor and stator protections, frequency and voltage protections, reverse power, out-of-step, shaft and mechanical protections, breaker failure, etc.
• Ancillary functions: fault diagnostics, disturbance records, event records and fault recorder
• CT/VT supervision and CT saturation detection
• GPS clock synchronization
• Communication protocols: IEC61850 MMS & GOOSE, IEC60870-5-103, MODBUS, DNP 3.0