Product Overview

The PCS-943 series is a digital high-voltage transmission line complete fiber-optic current differential protection device. It features fast primary protection based mainly on split-phase current differential and zero-sequence current differential elements, plus a full set of backup protection consisting of three-stage phase-to-phase and ground distance protection and four-stage zero-sequence directional overcurrent protection. The device includes three-phase single-shot reclosing, overload alarm, tripping/closing operation circuits, and AC voltage switching circuits. It can serve as primary and backup protection for 110kV transmission lines. The device fully supports digital substation functions, IEC 61850-9-2 sampling value transmission protocol, IEC 61850 communication protocol, and real-time GOOSE functionality.

Product Functions

Protection Functions

Split-phase power-frequency variation differential protection

Split-phase current differential protection

Zero-sequence current differential protection

Three-stage phase-to-phase distance protection

Three-stage ground distance protection

Quadrilateral ground and phase-to-phase distance protection (can serve as remote backup for low-voltage side bus faults of transformers)

Four-stage zero-sequence directional overcurrent protection

Asymmetrical successive instantaneous tripping

Two-stage phase overcurrent protection upon PT disconnection

Distance and zero-sequence acceleration protection

Oscillation blocking

Automatic reclosing

Supports multiple pilot communication modes including dedicated fiber, multiplexed fiber, and 5G

Supports 3–5 terminal differential multi-terminal application scenarios

Auxiliary Functions

Online hardware and loop detection

Impedance-based fault location

Traveling-wave fault location (optional)

Minute pulse, second pulse, and IRIG-B time synchronization

256 event reports, 64 fault recording reports

Diverse communication solutions supporting power industry standards IEC 60870-5-103 and IEC 61850

User-friendly HMI with convenient supporting debugging software and powerful waveform analysis tools