Digital Grid Monitoring Protection Relays

• The GWPR400-FV Underfrequency and Undervoltage Protection and Load Shedding Relay is a numerical protection and control relay designed to support power system frequency and voltage stability. It integrates underfrequency protection (ANSI 81U), undervoltage protection (ANSI 27), automatic load shedding, accelerated load shedding based on the rate of change of frequency (df/dt) and the rate of change of voltage (dU/dt), voltage transformer (VT) circuit failure supervision and protection blocking functions.
• The GWPR400-FV relay monitors the voltage of two busbar sections and provides eight underfrequency load-shedding stages and eight undervoltage load-shedding stages, each comprising five basic stages and three special stages. Its programmable trip output matrix supports up to 60 load feeder circuits in total, enabling selective load disconnection to reduce the risk of frequency and voltage instability.
• The relay provides two Ethernet ports and one RS-485 interface, supporting IEC 60870-5-103, IEC 60870-5-104 and Modbus communication protocols, with optional IEC 61850. NTP and IRIG-B time synchronisation are also supported. The GWPR400-FV relay can be integrated into substation automation systems (SAS) and SCADA platforms for remote monitoring, event recording, disturbance recording and operational data transmission.

The GWPR300-FV Voltage & Frequency Control Relay is designed for emergency control under abnormal grid frequency and voltage conditions. It provides three-stage underfrequency/overfrequency/undervoltage/overvoltage load-shedding tripping, and can also operate as a terminal execution device to execute remote trip commands or load-shedding commands issued by a regional stability control system.

Communication

• 2 Ethernet ports (supporting IEC 60870-5-104 protocol)
• 2 Ethernet ports (optional, supporting IEC 61850 protocol)
• 1 RS-485 serial communication port (supporting Modbus RTU protocol)
• Time synchronisation: communication message time synchronisation, SNTP, IRIG-B
• Printing interface: supports a dot-matrix printer with serial communication (prints settings, event records and disturbance records)

The GWPR200-FS Fault Separation Relay is suitable for the load side or small power source side of 33 kV, 22 kV, 11 kV and lower-voltage power systems. When specified grid fault or abnormal operating conditions are detected, the relay rapidly issues a trip command to separate the local power system or small power source from the utility grid, helping prevent the disturbance from further affecting the local system. It is widely used in hydroelectric, thermal, photovoltaic, gas turbine and captive power plants. It can be installed in a panel or locally in a switchgear cabinet. The device employs a high-speed 32-bit microcontroller with an integrated DSP and floating-point unit (FPU), integrating protection, measurement, energy metering, communication, fault recording and time synchronisation functions. It features a large LCD display and a user-friendly operating menu. Each protection and separation function is modular, functionally independent and flexibly configurable.​

Communication Functions (listed by hierarchy):
• 2 Ethernet ports (supporting IEC 60870-5-103, optional)
• 1 RS-485 communication port (supporting Modbus RTU)​

Time Synchronisation Interfaces: Supports protocol-based time synchronisation, SNTP time synchronisation and IRIG-B time synchronisation.

The GoWatron GWPR200-RP Reverse Power Protection Relay is primarily designed for grid-connected photovoltaic systems. It provides protection tripping in response to reverse power and automatic closing when forward power is restored. The relay supports four reverse-power trip outputs and four closing-command outputs. It supports both local installation in switchgear and centralised installation in a protection panel. Integrating protection, measurement, control, communication and event recording functions with comprehensive self-supervision, the GWPR200-RP is a dedicated protection relay for distributed PV grid-connection applications.

• The relay is equipped as standard with an RS-485 interface supporting Modbus RTU.
• Optional dual Ethernet ports support IEC 60870-5-103 over Ethernet.
• Supported time-synchronisation methods include message-based time synchronisation, SNTP network time synchronisation and IRIG-B.

• The GoWatron GWPR300‑FS Fault Separation Relay is designed for fault separation on the load‑side or small‑generation‑side applications for 132 kV, 33 kV and 10 kV (or 11 kV) voltage levels. It is widely deployed in hydropower plants, thermal power plants and gas‑fired power plants. Upon occurrence of faults such as over‑/under‑frequency and over‑/under‑voltage, the relay trips the generator circuit breaker to isolate the local plant from the utility grid and reliably disconnects faulty power sources, maintaining safe and stable operation of the power system.
• Dual Ethernet ports supporting IEC 60870‑5‑104/103; IEC 61850 available as option;
• RS485 interface for Modbus‑RTU. Supports IRIG‑B, SNTP and message‑based time‑sync modes.

GWPR200-AIP Anti-Islanding Protection Relay is designed for distributed photovoltaic power projects at 11kV and 22kV voltage levels. It is a digital protection relay specially developed to prevent islanding conditions.This relay can be used with the GWPR200-FL Grid Fault Disconnection Relay and GWPR200-D Power Quality Online Monitor to form a grid-connected protection panel, or flush-mounted on the panel of the PV grid-connected cabinet.

Communication Interfaces:

• 2 Ethernet ports (supporting IEC 60870-5-103; optional)
• 1 RS485 communication port (supporting Modbus-RTU protocol)
• Time synchronization via communication message, SNTP, and IRIG-B