Abstract: The traditional low-voltage motor protection is achieved through the relay protection secondary circuit, but we combine the characteristics of the auxiliary control equipment of the power plant and its control requirements, and recommend the ARD2F intelligent motor controller. The following is a comprehensive introduction to the characteristics of ARD2F intelligent motor controller products and its intelligent protection, measurement, control and communication.

　　Keywords: motor protection, intelligence, communication

　　1.Blackground

　　Because the use of motor equipment in power plants is gradually increasing, the normal operation of the motor has become a prerequisite for the normal operation of other equipment. Therefore, the reasonable selection and use of motor controllers is responsible for normal industrial site production work. Only on the basis of the normal function of the motor, it can be ensured that the working process of the entire motor equipment will not be disturbed and can operate normally. In a power plant in Sri Lanka, we recommend our ARD2F series to customers.

　　In the protection design of power plant electrical equipment, the application and protection configuration of low-voltage motors can be designed with a variety of solutions. In the past, thermal relays, circuit breakers (or fuses) were used as motor overload protection, phase failure protection, short-circuit protection and Control components, our ARD2F intelligent motor controller can realize heavy load starting and realize the temperature protection of the motor. It also provides a variety of measurement and control functions and a variety of motor control modes, which can meet the protection and control requirements of the motor, and effectively protect the motor safe operation. Next, we introduce the actual application of the ARD2F intelligent motor controller in power plants for a specific introduction.

　　2.Functional requirements for motor controllers in the power plant

　　In power plants, the electricity consumed by motors accounts for a large part of the total power generation, and various types of fans, pumps, and air compressors account for more than half of the electricity consumed by motors. Due to the harsh working environment of the motors in power plants, they are often prone to faults such as locked rotor, short circuit, open phase or long-term overload operation, so there is an urgent need for a real-time protection and control of the motor to ensure the normal operation of the motor in the power plant.

　　Therefore, ARD2F can measure the voltage and current full power parameters of the power plant motor, and has communication functions. The controller needs to have functions such as self-diagnosis output, power-off output, and fault recording, which are summarized as the following functions:

　　1.Realize complete motor protection function

　　The controller collects three-phase AC current, three-phase AC voltage, residual current, PTC thermal resistance resistance, motor electrical energy and other electrical parameters, as well as signals such as various motion states during the operation of the motor, and then processes and calculates internally by the controller. Realize the motor starting overtime, overload, blockage, underload, phase failure, three-phase current imbalance, residual current (ground/leakage), temperature, external fault, phase sequence, overvoltage, undervoltage, underpower, overpower, Comprehensive comprehensive protection such as tE time, and then ensure the safe and continuous operation of the power plant production work.

　　2.Realize a variety of motor control methods

　　The intelligent motor controller realizes a variety of different motor starting control through program control. The operation control authority realized by the controller includes: 1) RS-485 communication interface to realize remote control; 2) It can be carried out through the buttons on the display module Operation control; 3) Realize remote automatic control through DCS system control DI terminal; 4) DI terminal on-site control.

　　3. Realize real-time monitoring of motor operation on site

　　Through the controller, the power plant can observe the voltage, current, frequency and other parameters of the field motor equipment in the running process and the current operating status of the motor in real time. Operate the buttons on the display module to set the starting mode of the power plant motor equipment (optional manual start, two Step start, two-speed start and protection mode).

　　4.Realize communication function

　　The controller can communicate with the upper computer management system through the RS-485 communication interface through the Modbus-RTU or Profibus-DP communication protocol, and send the information to the background management system in the shortest time and send an alarm signal to the fault information to make the operation The personnel can find the cause of the fault and eliminate the fault in time to realize the real-time transmission function of the data of the electric motor equipment of the power plant.

　　ARD2F intelligent motor controller adopts modular product structure, including main control module, transformer module and display module, and can be equipped with other functional modules and accessories of ARD2F intelligent motor controller according to the actual application of the industrial field.

　　3.The effect of using ARD2F intelligent motor controller in power plant

　　Protecting the operation of the motor and ensuring the continuous and uninterrupted operation of the motor are vital to production. The benefits of using the ARD2F intelligent motor controller for power plants include:

　　1.High networking flexibility, easy to control

　　The application of motor controllers and power distribution products in power plants has the same proportions, and they are inseparable in the process of realizing the networking. ARD2F intelligent motor controller provides RS-485 communication interface, and realizes the choice of multiple protocols (Modbus-RTU/Profibus-DP). Through the communication between RS-485 and the host computer, it is convenient for engineers to realize through the computer background Remote automatic control and online monitoring of equipment operation status, etc.

　　2.Real-time display of parameters, convenient on-site inspection

　　The ARD2F intelligent motor controller adopts a modular product structure. The display module is installed in the DCS cabinet, and the current running status of the motor can be observed in real time through the LCD interface, which is convenient for users to maintain and control the on-site motor.

　　3.Energy saving

　　The role of the motor controller in energy saving and consumption reduction began to be paid attention to. The ARD2F intelligent motor controller can automatically stop when the motor equipment is under load and other operating conditions, effectively avoiding the waste of energy and saving money for the enterprise.

　　4.Information centralization

　　The user can monitor the operating status of each motor in the system in real time through the communication module, and observe the operating parameters of the equipment at any time, such as: motor current, voltage, motor operating status, motor power and other parameters. By analyzing the collected information, the user can Real-time processing of the motor running status of each device improves the safety and reliability of the entire control system.

　　5.Intelligent automatic control protection

　　The ARD2F intelligent motor controller is flexible to use. The alarm and protection parameters can be preset to different values through the software according to the actual operating conditions of the power plant's motor equipment, so as to avoid excessive protection from affecting actual production. After the user selects the ARD2F intelligent motor controller, once the on-site motor fails, the controller controls the motor to stop running in time, and makes corresponding instructions and records of various fault information, so that the user can query the fault information. When the grid fault causes a large voltage fluctuation or short-term power failure and recovery, the motor controller can be restarted with the anti-shake function.

　　6.Record motor fault information for easy on-site problem analysis

　　Most of the motor equipment working in power plants are in high temperature, humidity, and dusty conditions, which are prone to failure. Once a failure occurs, it is difficult for maintenance personnel to find the cause of the failure in the first time, and it takes a certain amount of time, manpower and Material resources can analyze the cause of the failure. The ARD2F intelligent motor controller has powerful fault and event records and operation management information, which saves a lot of time for field maintenance personnel, improves the work efficiency of maintenance personnel, and further improves the performance of the entire control loop.

　　4.Summary

　　The ARD2F intelligent motor controller is used in the low-voltage motor protection and monitoring system of the power plant, which not only improves the automation level and reliability of the control loop, but also improves the comprehensive benefits of the enterprise, and achieves the unity of reliability and economy. Moreover, with the continuous development of technology, ARD2F intelligent motor controller will play an increasingly important role in the protection and measurement and control of low-voltage motors in power plants.