GWPR320-LD Fiber-Optic Line Differential Protection Relay

Product Functions

Protection Function List

• (ANSI 87L) Fiber-optic split-phase current differential main protection
• (ANSI 67) Three-stage directional phase overcurrent protection (with undervoltage blocking)
• (ANSI 67) Standard / Very Inverse / Extremely Inverse three-type inverse-time directional phase overcurrent protection
• (ANSI 67N) Three-stage directional zero-sequence overcurrent protection
• (ANSI 67N) Standard / Very Inverse / Extremely Inverse three-type inverse-time directional zero-sequence overcurrent protection
• (ANSI 79) Three-phase single-shot auto-reclosing. Three configurable modes: synchro-check, undervoltage-check and non-check. Independent reclosing blocking can be configured for differential protection operation scenarios.
• (ANSI 50/51) Independently configurable pre-acceleration and post-acceleration protection (enable/disable)
• (ANSI 49) Overload alarm and overload tripping functions (dual configurable logic)
• (ANSI 81F) Under-frequency load shedding protection (with ROCOF blocking, undervoltage blocking and overcurrent blocking)
• (ANSI 27) Undervoltage load shedding protection (with negative-sequence blocking, voltage ROCOF blocking and overcurrent blocking)
• CT disconnection alarm & blocking, differential overcurrent alarm, fiber channel fault alarm
• PT disconnection monitoring & alarm, control circuit disconnection monitoring & alarm

Acquisition, Control and Communication Functions

• Electrical Parameter & Remote Signal Acquisition: Acquires three-phase current, three-phase voltage, active power, reactive power, system frequency and other electrical parameters; supports 13-channel dry-contact remote signal input.
• Event Recording: Completely stores fault records, protection operation records, remote signal status changes and device operation logs; all data is retained after power failure.
• Local & Remote Control: Supports local and remote circuit breaker closing/opening operations, remote protection parameter modification, and protection function enable/disable. Built with an adaptive circuit breaker operating mechanism and integrated anti-pumping function.
• Time Synchronization & Optical Interface: Supports SNTP and IRIG-B time synchronization modes; adopts FC single-mode 1310nm fiber-optic differential interface, with a maximum repeater-free transmission distance of 100km.

Core Technical Parameters

• Operating Power Supply: AC 127/220V or DC 110/220V (optional); normal operating power consumption ≤10W
• AC Analog Input: CT secondary rated current 1A/5A (configurable upon ordering); rated voltage 57.7V/100V, compatible with Y-type and V-V wiring modes
• Measurement Accuracy: Current/voltage measurement error ≤±0.2%; active/reactive power measurement error ≤±0.5%
• Protection Performance: Protection setting error ≤±3%; time delay error ≤±(1% of set value + 35ms); total operating time of differential protection ≤35ms
• Relay Output Contact Rating: Resistive load: DC 250V / 5A (breaking capacity ≥50W); mechanical service life: 100,000 operations
• Ambient Temperature: Operating temperature: -25°C ~ +55°C; storage temperature: -25°C ~ +80°C
• Insulation Performance: Insulation resistance between each circuit and earth ≥100MΩ (tested via 500V megohmmeter); power supply, sampling and output circuits withstand 2kV/1min power-frequency voltage; weak signal circuits withstand 500V/1min; fully compliant with GB/T 14598 standards
• Electromagnetic Compatibility & Mechanical Performance: Passed full-range high-level EMC tests including ESD, surge immunity and pulsed magnetic field interference; passed Class I vibration, shock and impact resistance tests, ensuring structural stability for long-term continuous operation
• Chassis Structure: 5U, 19/3-inch standard chassis; full front panel design and rear plug-in structure; rear-wiring flush mounting mode. Physical isolation between strong-current and weak-current circuits effectively improves electrical safety and stability.

Application Scenarios

• Applicable Equipment: 33kV and 10kV overhead transmission and distribution lines, cable feeders, power transformer outgoing circuits
• Applicable Power Systems: Adaptable to ungrounded, resistance-grounded, arc suppression coil-grounded and solidly grounded power distribution systems
• Installation Methods: Flush mounting on on-site switchgears; centralized panel mounting in main control rooms
• Application Sites: Urban and rural substations, industrial and mining distribution substations, renewable energy step-up substations, industrial park power distribution facilities, and digital intelligent substations (with optional IEC 61850 functional module)

Product Core Features

• Adopts dedicated two-terminal fiber-optic differential calculation algorithm, which automatically completes CT ratio matching and phase compensation at both line terminals without external balancing resistors. Equipped with dual blocking logic of second-harmonic restraint and CT disconnection detection, effectively preventing protection maloperation during transformer energization and external short-circuit faults.
• Features hierarchical and comprehensive protection functions with independent configurable parameters for each protection item, satisfying time grading coordination requirements with upstream and downstream line protection relay.
• Integrates an adaptive circuit breaker operating mechanism with adjustable trip/close current ranging from 0.2A to 6A, with built-in anti-pumping and switch position monitoring functions.
• Equipped with a full-coverage fault alarm system, realizing real-time monitoring and alarm for fiber channels, CT, PT and control circuit abnormalities.
• Adopts 32-bit high-performance ARM main processor and large-capacity storage, which completely retains fault records and SOE event data for accurate fault analysis and troubleshooting.
• Dual-Ethernet + RS485 redundant communication design ensures high communication reliability, compatible with both traditional conventional substations and IEC 61850 digital intelligent substations.
• Adopts fully sealed wide-temperature chassis with strict strong/weak current isolation design and excellent anti-electromagnetic interference capability, adapting to harsh operating environments such as switchgear rooms and outdoor prefabricated substations.
• Supports full-circuit hardware self-diagnosis. All hardware faults can be indicated via local LED indicators and uploaded to the remote monitoring system in real time.