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Renewable Energy Relay Protection

Renewable energy relay protection for solar power plants, wind turbines, and distributed energy resources (DER). Products include fault disconnection, anti-islanding, and power regulators, among others.

Supplementary Electrical Solutions

Renewable Energy Relay Protection

Renewable Energy Relay Protection Solutions, covering solar power plants, wind turbines, and distributed energy resources (DER).

Among them, solar protection relays are specifically designed for the safety protection of grid-connected photovoltaic systems. They effectively respond to abnormal voltage, frequency deviations, current overloads, reverse power, islanding effects, and other various grid faults, ensuring stable and reliable system operation.

Contact us today to equip your renewable energy projects with reliable protection relays. Let’s work together to build a safer, smarter, and more sustainable grid!

Solar Protection Relays for PV Power Plants

Solar protection relays monitor electrical parameters in grid-connected PV systems and disconnect the solar generation system when abnormal voltage, frequency, current, power flow or loss-of-grid conditions are detected.

Common Protection Functions

Protection Function ANSI Application
Overcurrent 50/51 PV feeder
Earth Fault 50N/51N AC system
Overvoltage 59 Grid connection
Undervoltage 27 Grid connection
Overfrequency 81O Grid protection
Underfrequency 81U Grid protection
Reverse Power 32 Zero-export PV
Anti-Islanding 78 / ROCOF Grid-connected PV
Synchronism Check 25 Grid connection

Solar Protection Relay Products

Anti-Islanding Protection Relay

400V Anti-Islanding Protection Relay

Designed for low-voltage distributed generation systems (such as PV, energy storage, and wind power), this relay quickly detects grid abnormalities and triggers tripping to prevent islanding, protecting both equipment and the power grid.

Features: Dual islanding detection (passive + active), trip time <0.5s, complies with grid connection standards, supports RS485 communication.

Applications: Solar PV stations, energy storage systems, microgrids, etc.

ASF-441H Anti-islanding Protection Product

For 10kV+ grid-connected PV projects. Monitors voltage, frequency, and phase; detects islanding and grid faults; trips within <0.2s.

  • Dual detection (passive + active)

  • Meets GB/T 19964, NB/T 32004

  • RS485/Ethernet, Modbus, IEC 103, IEC 61850

  • -40°C ~ +70°C, high anti-interference

Ideal for large PV stations, collector stations, and PV-storage integration.

Reverse Power Protection Relay

Solar reverse power protection is used to prevent photovoltaic systems from feeding active power back into the grid. When the PV generation exceeds the load demand and power flows in the reverse direction, the relay trips or reduces output to prevent grid voltage rise, equipment overloading, and power quality degradation.

Typical applications include:

  • “Self-consumption, no feed-in” PV systems

  • Anti-reverse power control in energy storage systems

  • PV integration at the end of distribution networks

The protection logic is typically based on active power direction and magnitude at the point of common coupling. Trip thresholds and time delays can be set according to project requirements, ensuring coordination with grid dispatch.

System Separation Protection

Rapidly disconnects distributed generation from the main grid during grid faults to prevent fault escalation.

  • Monitors voltage, frequency, and phase; trips within milliseconds upon abnormalities

  • Criteria: over/under frequency, over/under voltage, ROCOF, phase jump

  • Suitable for 400V to 35kV+, supports Modbus, IEC 103, IEC 61850

Applications: PV/wind grid connection, energy storage, microgrids, captive power plants.

Solar Transformer Monitoring / Protection

Provides electrical protection and non-electrical monitoring for PV step-up transformers to ensure equipment safety.

  • Electrical protection: overcurrent/instantaneous, zero-sequence, over/under voltage, differential (87T)

  • Non-electrical monitoring: temperature (49), Buchholz/gas (63), overexcitation (24)

  • Suitable for 400V~35kV, supports Modbus, IEC 103, IEC 61850

  • Integrated fault recording, industrial-grade design for harsh environments

Applications: PV step-up transformers, collector stations, PV-storage integration projects.

Wind Power Protection Relays

Wind power protection relays cover two major aspects: turbine protection and farm grid protection, ensuring safe, stable, and grid-compliant operation of wind turbines and wind farms.

Wind Turbine Protection

Protects generators, converters, and auxiliary equipment from electrical faults and mechanical abnormalities.

Key Functions:

Generator protection: overcurrent (50/51), differential (87G), stator earth fault

  • Converter protection: overcurrent, over/under voltage, DC-link overvoltage

  • Grid abnormality protection: over/under frequency (81), over/under voltage (27/59), synchronization check (25)

  • Mechanical monitoring: vibration, overspeed, gearbox temperature, cooling system

Key Features:

  • Fault clearing time <100ms, multi-function integration

  • Industrial wide-temperature design (-40°C~+70°C)

  • Supports Modbus, IEC 103, IEC 61850 communication

Wind Farm Grid Protection

Ensures the entire wind farm integrates safely into the utility grid, covering collector lines, main transformers, busbars, and PCC.

Key Functions:

  • Transformer protection: differential (87T), overcurrent (50/51), Buchholz (63), temperature (49)

  • Feeder protection: overcurrent/zero-sequence (50/51, 50N/51N), directional overcurrent (67)

Busbar protection: differential (87B), breaker failure (50BF)

Outgoing lines: distance protection (21)

Grid support: FRT, power factor control, anti-islanding (78), system separation

Key Features:

  • Comprehensive substation-level protection, GOOSE fast communication

  • Event recording and fault recording, SCADA remote monitoring

  • Complies with VDE, E.ON, GB/T, IEEE 1547, and other grid standards

Summary

Wind power protection relays provide end-to-end protection from turbines to grid connection. Advanced communication and recording capabilities ensure safe and reliable wind farm integration.

Solar and Wind Protection Relay Selection Guide

Identify Application Scenario

Application Voltage Level Protection Focus
Rooftop / Small Distributed PV 400V, 11kV Anti-islanding, reverse power, over/under voltage, over/under frequency
Large Ground-Mounted PV 11kV~110kV Transformer protection, line protection, anti-islanding, system separation
Wind Turbine 690V, 11kV Generator protection, converter protection, mechanical monitoring
Wind Farm Collector / Grid Connection 11kV~220kV Feeder protection, busbar protection, distance protection, FRT

Select by Equipment Type

Equipment Recommended Protection (ANSI)
Step-up Transformer 87T, 50/51, 50N/51N, 24, 63, 49
Feeder / Collector Line 50/51, 50N/51N, 67/67N, 79
Busbar 87B, 50BF
Transmission Line 21/21N, 67/67N, 87L
Capacitor Bank 50/51, 59, 60
Wind Generator 50/51, 87G, 64S, 81

Grid Connection Requirements

  • Anti-islanding: 78, ROCOF, vector shift

  • Reverse power protection: 32

  • Fault ride-through: FRT, voltage/frequency protection

  • Standards compliance: GB/T, VDE, IEEE 1547, etc.

Environmental Conditions

  • Outdoor / wide temperature: -40°C ~ +70°C

  • High humidity / coastal: Conformal coating, IP rating

  • Strong interference: High EMC immunity (IEC 61000-4)

  • Remote sites: SCADA remote monitoring

Communication Requirements

  • Interfaces: RS485, Ethernet, fiber optic

  • Protocols: Modbus, IEC 103, IEC 61850 (GOOSE/SV/MMS)

  • Functions: Event/fault recording, remote setting changes

Quick Selection by Voltage Level

Voltage Level Recommended Relays
400V / 11kV Anti-islanding, overcurrent, reverse power, voltage/frequency
22kV / 33kV / 35kV Overcurrent, directional, zero-sequence, transformer differential
66kV / 110kV Distance, transformer differential, breaker failure, IEC 61850
220kV+ Pilot differential (87L), multi-zone distance, dual-redundant

Selection Checklist

  • □ Equipment type (transformer/line/busbar/turbine/inverter)
  • □ Voltage level
  • □ Protection functions (ANSI codes)
  • □ Grid codes and local standards
  • □ Environmental conditions (temperature/humidity/interference)
  • □ Communication protocols and SCADA integration
  • □ Future expansion and system coordination

Protection Relays for New Energy Power Stations

In addition to PV-specific protections (anti-islanding, reverse power, etc.), new energy stations (PV and wind) are equipped with complete substation-level protection devices, covering transformers, lines, busbars, capacitor banks, and auxiliary transformers.

Key protection includes:

  • Transformer: 87T, 50/51, 50N/51N, 24, 63, 49

  • Line: 50/51, 67/67N, 21, 79

  • Busbar: 87B, 50BF

  • Capacitor/Reactor: Overcurrent, 59, unbalance

  • Auxiliary Transformer: Overcurrent, zero-sequence, temperature

These work together with PV-specific protections to form a complete protection system, ensuring safe and reliable operation of generating units, substations, and grid connections.

Our Technical Advantages

  • Adaptive New Energy Fault Algorithm: Precisely identifies weak faults under low current and complex harmonics, solving the low sensitivity and misoperation issues of conventional protection.

  • Full-Scenario Layered Protection: Covers PV DC/AC sides, wind farm lines, and booster stations, enabling full-range fault monitoring and rapid isolation.

  • Strong Grid Adaptability: Embedded with LVRT and frequency ride-through logic, adapting to the intermittent and fluctuating nature of new energy to prevent large-scale unit disconnection.

  • High Reliability & Anti-Interference: Complies with industrial EMC standards, resists harmonics and electromagnetic interference, and operates stably in complex power plant environments.

  • Intelligent Cooperative Operation: Seamlessly connects to master stations, supports fault recording, remote monitoring, and early warning, enhancing substation automation levels.

Solar Protection Relay FAQ

What is a solar protection relay?

A protective device for PV systems that monitors voltage, current, and frequency at the grid connection point, and trips upon detecting abnormalities (islanding, reverse power, over/under voltage/frequency, etc.) to protect equipment and the grid.

What protection functions are used in solar power plants?

Common functions: anti-islanding (78), overcurrent (50/51), zero-sequence overcurrent (50N/51N), over/under voltage (59/27), over/under frequency (81), reverse power (32), system separation, and transformer protection (87T, 63, 49).

What is an anti-islanding protection relay for solar PV systems?

A relay that prevents unintentional islanding by monitoring grid status at the PCC and tripping the PV system within a specified time (typically <0.5s or <0.2s) upon grid loss, using passive and active detection methods.

Is a protection relay required for a solar power plant?

Yes. Protection relays are mandatory for grid-connected solar plants as required by grid codes (e.g., GB/T, IEEE 1547, VDE) to ensure personnel safety, equipment protection, and grid stability.

What is reverse power protection in a solar power system?

Reverse power protection (ANSI 32) prevents power from flowing back to the grid. Used in self-consumption systems where no export is allowed; trips or reduces output when reverse power is detected.

What is the difference between a solar protection relay and an inverter protection function?

Aspect Solar Relay Inverter Function
Device Standalone Built-in
Reliability Higher, independent Dependent on inverter
Scope Full system (incl. transformer/line) Limited to inverter
Communication SCADA, IEC 61850 Limited
Backup Provides backup No self-backup

Where is a solar protection relay installed?

At the PCC/grid connection cabinet, LV distribution panels, MV switchgear (11kV~35kV), or central relay panels.

How do I choose a solar protection relay?

Consider voltage level (400V~110kV+), system type (on-grid/off-grid), required protection functions, grid code compliance, communication protocol (Modbus, IEC 103, IEC 61850), environmental conditions, and certifications.

Can solar protection relays support IEC 61850?

Yes. Many modern relays support IEC 61850 (GOOSE, SV, MMS) for seamless integration into digital substations and SCADA systems.

Can you supply solar protection relays for utility-scale PV projects?

Yes. We supply relays for utility-scale PV (11kV~110kV+), including anti-islanding, transformer differential (87T), feeder protection (50/51), directional (67), distance (21), and busbar differential (87B). Contact us with your project specs for recommendations and quotes.

General Equipment & System Integration Inquiry

Whether you need individual protection relays, control panels, or a complete secondary system integration, please fill in the form below. We provide technical parameters, competitive quotations, engineering drawings, and on-site support. Our expert team is ready to assist you within 24 hours.
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High Quality

Stable performance, reliable design, ensuring safe operation for power system protection and grid stability.

Fast Delivery

Timely delivery to support your urgent orders and project schedules efficiently and professionally at any time.

Best Warranty

Professional Warranty: Reliable after-sales support for stable relay protection and long-term customer satisfaction.