Earth-leakage protection relay PCS-931S

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Product Overview
PCS-931S line differential relay integrates primary and backup protection with control functions for overhead lines, cables and hybrid transmission lines across multiple voltage levels. Designed for power system operators and utilities, it provides comprehensive protection, flexible configuration via PCS-Studio and advanced fault-location capabilities to reduce outage time and operating cost.

Protection and Control

• High-speed DPFC distance protection (21D)
• Six-zone phase-to-phase and phase-to-ground distance protection (21L)
• DPFC and steady-state current differential protection (87L)
• Neutral current differential protection (87L)
• Pilot distance and pilot directional earth-fault protection (85)
• Power swing blocking/releasing logic (PSBR)
• Multi-stage phase and earth-fault overcurrent (67P/67G, 50/51)
• Negative-sequence overcurrent (67Q) and residual protections
• Switch-on-to-fault (SOTF), breaker failure (50BF), flashover (50F), dead-zone (50DZ)
• Broken conductor (46BC), pole discrepancy (62PD), stub differential (87STB)
• Out-of-step protection (78), auto-reclosing (79) and switchgear control
• Voltage selection, drift auto-adjustment and synchronism check (25)
• Single-ended impedance and travelling-wave fault location (single- and double-ended)

Synchrophasor Measurement

• GPS/IRIG-B time synchronization
• Synchronized phasors: Ua, Ub, Uc, U1, U2, U0, Ia, Ib, Ic, I1, I2, I0
• Analog values: P, Q, frequency, ROCOF (df/dt)
• IEEE C37.118 compliant PMU output; supports P or M class
• Transmit to PDC via TCP/UDP; up to 4 clients; configurable data rates (2f0, f0, f0/2)
• Measurement of up to 32 binary status

Measurement

• Current/voltage sampling: 2.4 kHz and 9.6 kHz
• Travelling-wave current sampling: 1 MHz
• Energy metering (active/reactive, import/export)
• Power (apparent/real/reactive), power factor and frequency measurement
• Calibration for current, voltage and active/reactive power

Recording

• Event recorder: 1024 disturbance records, 1024 binary events, 1024 supervision events
• Control and device logs: 256 control logs, 1024 device logs
• Waveform records: 64 disturbance waveforms, 64 TWFL records, 64 high-frequency records (COMTRADE compatible)

Supervision and Self-monitoring

• CT/VT circuit supervision
• Trip/close coil and DC supply supervision
• Pilot communication and channel status statistics
• Circuit breaker supervision (travel time, interrupted current, trip counter, remaining life)
• Self-diagnostic functions

Pilot Channel Scheme

• Optional single- or dual-fiber pilot channels
• Support for G.703 and C37.94

Communication Interface

• 2 or 4 × 100Base-TX copper Ethernet ports
• 2 or 4 × 100Base-FX optical Ethernet ports
• Extendable 1000Base-SX optical port for PRP/HSR
• 2 RS-485 ports for SCADA; additional RS-485/TTL/BNC for clock sync
• Front and rear RJ45 ports for debugging

Communication Protocols

• IEC 61850 (Edition 1 & 2)
• IEC 60870-5-103, DNP3.0, Modbus
• IEC 62439 PRP / HSR, IEEE 802.1w RSTP

Digital Application (IEC 61850 Support)

• IEC 61850 MMS server, GOOSE and SV (IEC 61850-8-1, -9-2LE)
• Station-level and process-level Ethernet ports (100Base-TX/FX, extendable 100Base-FX / 1000Base-SX)

Clock Synchronization

• IRIG-B via RS-485/TTL or BNC
• PPS via serial, BNC or binary input
• IEEE 1588 and SNTP over Ethernet
• Clock messages via IEC 60870-5-103, Modbus and DNP3.0

Cybersecurity and Standards

• Compliance: NERC CIP, IEC 62351, IEC 62443, IEEE 1686

Available Documents

• Catalog PDF: PCS-931S Line Differential Relay
• Technical Manual, Datasheet and Application Manual (documents available)

Technical specifications

• Model: PCS-931S
• Application: protection and control for overhead lines, cables and hybrid transmission lines
• Sampling rates: 2.4 kHz / 9.6 kHz (I/V), 1 MHz (travelling-wave)
• Phasor standards: IEEE C37.118 series; synchrophasor communication per IEEE C37.118
• Event capacity and waveform storage: see Recording
• Communication ports and protocols: see Communication Interface / Protocols
• Time sync: IRIG-B, PPS, IEEE 1588, SNTP
• Pilot: optional single/dual fiber; G.703 and C37.94 support
• Supervision: CT/VT/coil/DC/channel/breaker monitoring and self-diagnostics
• Cybersecurity: NERC CIP, IEC 62351, IEC 62443, IEEE 1686
• Configuration: PCS-Studio