Thermal protection relay PCS-931

over-frequencyphase asymmetryearth-leakage

Overview
The PCS-931 line protection relay provides integrated differential and distance protection for overhead lines and underground cables. It combines phase-segregated differential (including DPFC) with multi-zone distance elements and pilot schemes to deliver comprehensive protection for diverse transmission-line configurations.

Protection and Control

• Phase-segregated DPFC differential protection (87L) and phase/neutral current differential
• Multi-zone distance protection (five zones for phase-to-phase and phase-to-ground) and high-speed DPFC distance element (21P/21G/21D)
• Pilot schemes for distance and directional earth-fault protection (single or dual fiber channels supported)
• Breaker-failure protection (single or dual breaker), dual breaker auto-reclosing and single/three-pole tripping
• Power swing blocking and out-of-step protection, switch-onto-fault (SOTF) logic, broken conductor and dead-zone protection
• Over/under voltage and frequency protection, negative-sequence and thermal overload protections

Monitoring and Measurement

• Fault detection and phase selection, fault locator with parallel-line compensation
• Energy measurement (active/reactive, import/export)
• CT/VT supervision and automatic adjustment, frequency tracking
• Event and disturbance recording (COMTRADE compatible), comprehensive logging and diagnostics

Communications

• IEC 61850 support: IEC 61850-8-1 (MMS/GOOSE) and IEC 61850-9-2 Sampled Values
• Multiple Ethernet ports (10/100 copper, optional 100Base-FX) and serial interfaces (RS-485/RS-232), support for DNP3 and IEC 60870-5-103
• Optional single/dual fiber pilot channels (G.703, C37.94) and optional SV/GOOSE optical module

User Interface

• Front HMI with large LCD and 9-button keypad; front RJ-45 port for testing and setting
• Rear RS-232/RS-485 for printer and clock sync ports
• Clock synchronization via IRIG-B, SNTP, PPS, PPM and IEEE 1588
• Configuration and assistance via PCS-Explorer software

Technical specifications

• Model: PCS-931
• Applications: overhead lines and underground cables, series-compensated, double-circuit, heavily loaded, weak-infeed, short and long lines
• Pilot channels: optional single/dual fiber (G.703, C37.94)
• Ethernet: up to four 10Base-T/100Base-TX and up to two 100Base-FX optical ports
• Recording: event and disturbance recorders (COMTRADE), extensive logs
• Protection functions: differential (87L), distance (21P/21G/21D), overcurrent, earth-fault, breaker failure, out-of-step, auto-reclosing, and more