Ankerui anti islanding protection device AM5SE-IS

I. Overview

The AM5SE series microcomputer protection and measurement device (hereinafter referred to as the device) integrates protection, control, measurement, communication, and monitoring functions, with abundant resources, complete configuration, convenient maintenance, and stable performance. It is suitable for the protection and measurement of power systems with voltage levels of 35kV and below, and realizes the protection of incoming lines, main transformers, distribution transformers, motors, capacitors, busbars, PTs, etc. The application areas cover industries such as power, water conservancy, transportation, petroleum, chemical, coal, metallurgy, etc.

The hardware design of the device adopts reliable configuration, and the software is equipped with specialized protection algorithms. It has strong anti-interference performance, high reliability, and flexible protection implementation methods. It can be used in conjunction with the Acrel-2000Z power monitoring system to provide guarantees for the safe and reliable operation of the power system.

2、 Characteristics:

Features

Quick islanding prevention: Real time monitoring of power grid parameters, able to quickly cut off the connection between the photovoltaic system and the power grid within milliseconds to 2 seconds in case of power outage or abnormality, preventing the formation of islanding effects.

Sohu Network has multiple protection functions, including reverse power protection, three-stage overcurrent protection, frequency protection, frequency jump tripping, overvoltage protection, undervoltage protection, etc., which can cope with various fault situations.

Automatic control of Sohu: automatic closing function under pressure. After the power grid returns to normal, the parameters are automatically detected and reconnected to the grid, reducing manual intervention.

Fault monitoring and recording: It can record the time, voltage frequency changes, and other data of islanding events, which is convenient for analyzing the cause of faults. It can also monitor the operating status in real time and give timely alarms in case of abnormalities.

3、 Technical advantages:

High precision measurement: Using a 16 bit AD sampling chip, the voltage/frequency detection accuracy reaches 0.2 level.

Intelligent algorithm: Combining fast Fourier transform and slip frequency detection to reduce misjudgment rate.

Strong compatibility: Supports multiple communication protocols such as Modbus and IEC61850, and is compatible with different brands of inverters.

Convenient communication: Supports RS485, Ethernet, or wireless communication, allowing real-time data exchange with photovoltaic power station monitoring systems or grid dispatch centers, and receiving remote commands.

Application scenarios: Suitable for new energy grid connected power supply systems such as 35kV, 10kV, and low-voltage 380V photovoltaic power generation and gas power generation, widely used in distributed photovoltaic power stations, energy storage system grid connection points, microgrids, and multi energy complementary systems.

Standard compliance: Strictly follow national standards such as GB/T 50865-2013 to ensure that the photovoltaic system passes acceptance and is safely put into operation.

The anti islanding protection device is the "gatekeeper" for the grid connection safety of distributed energy systems. Its core function is to quickly cut off the connection between distributed power sources and the grid in case of grid failure or power outage, avoiding risks such as equipment damage and personnel safety caused by the "islanding effect". Its application scenarios cover a wide range of distributed power generation and grid connected systems. The following provides specific explanations from three aspects: core scenarios, extended scenarios, and special scenarios:

Core application: New energy distributed power generation system

This is the main application area of anti islanding protection devices, which directly target the safety protection of new energy sources such as photovoltaics and wind power when connected to the grid.

Photovoltaic power station: Whether it is household small-scale photovoltaic (such as rooftop photovoltaic), industrial and commercial distributed photovoltaic (such as factory photovoltaic), or the grid connection point of centralized photovoltaic power station, this device must be equipped. When the power grid is shut down due to maintenance, malfunctions, or other reasons, the device can quickly detect abnormal voltage and frequency, cut off the connection between the photovoltaic system and the power grid, prevent the photovoltaic system from continuing to supply power to the power grid and forming an "island", and avoid electric shock to maintenance personnel or damage to equipment due to reverse power supply.

Wind power generation: Small distributed wind power (such as self built wind power by enterprises) also needs to be protected against islanding when connected to the grid. The output power of wind power systems is greatly affected by wind speed. If the power grid is not disconnected in a timely manner during abnormal conditions, it may lead to unstable voltage and frequency in isolated areas, and damage to electrical equipment.

Extended application: Other distributed power sources and energy storage systems

In addition to new energy, other types of distributed power sources and energy storage systems also rely on this device to ensure safety when connected to the grid.

Gas/diesel generators: Some enterprises, hospitals, and other places will be equipped with gas or diesel generators as backup power sources. When connected to the grid for operation, if the grid suddenly loses power, the generator may form an island if it continues to supply power. The anti islanding protection device can detect voltage loss in the power grid, promptly cut off the connection with the power grid, ensure that the generator only supplies power to internal loads, and avoid conflicts.

Energy storage system: In integrated photovoltaic and wind storage systems, the charging and discharging of energy storage batteries are closely related to the power grid. When the power grid is abnormal, the anti islanding protection device can prevent the energy storage system from supplying power to the external power grid alone, while protecting the energy storage equipment itself from damage caused by voltage and frequency fluctuations.

Special scenario: Microgrid and Multi energy Complementary System

In more complex microgrids or multi energy complementary systems, the role of anti islanding protection devices is more critical.

Microgrid: Microgrids can achieve "grid connected off grid" mode switching. When switching from grid connected mode to off grid mode, it is necessary to ensure disconnection from the main grid, and the anti islanding protection device can accurately detect the switching timing to prevent the microgrid from still being connected to the main grid and forming an islanding even after the main grid is cut off.

Multi energy complementary system: such as the hybrid power supply system of "photovoltaic+wind power+energy storage+mains power", the various power sources operate in coordination. When the power grid is abnormal, the anti islanding protection device needs to quickly cut off the connection with the main grid to ensure that all devices in the system operate stably in off grid mode and avoid power imbalance caused by islanding effects.

4、 Operating instructions

1. Front panel description

The human-machine interaction of the device is mainly carried out on the panel, including four parts: LCD display, LED light indication, buttons, and RS232 (DB9) maintenance.

The LCD screen adopts a 256 * 160 dot matrix, which can display real-time values of electrical parameters such as measured current, voltage, power, remote signaling, event records, device parameters, fixed value parameters, time, device version number information, etc.

LED lights are used to indicate the operating status, protection actions, and other information of the device. The specific indication content can be configured according to the user's needs. The default configuration shown in the figure is from the factory.

5、 The core application value of anti islanding protection device

The application scenario of anti islanding protection devices always revolves around the core of "safe grid connection between distributed power sources and power grids". Whether it is a single new energy power station or a complex microgrid system, their role is to prevent equipment damage, personnel safety, and grid restoration obstacles caused by islanding effects through real-time monitoring and rapid response. They are the safety guarantee equipment for the operation of distributed energy grid connection.