Application of intelligent motor protector in a cement plant

Renye Ankrui Electric Co.
, Ltd.
Shanghai Jiading 201801 Abstract: motor equipment is a widely used power device in cement enterprises, and cement production enterprises belong to high energy consumption, large pollution and need equipment continuous and uninterrupted work industry, motor as a power source of cement industry equipment, its safe, stable and reliable operation plays a vital role in the stable production of cement industry, this article comprehensively introduces the practical application of Accuray ARD2F intelligent motor protector in a cement plant, The characteristics of ARD2F intelligent motor protector products and their intelligent protection, measurement, control and communication are expounded for reference
in engineering design.
Keywords: cement, motor protection, intelligence, communication one, IntroductionWith the modern cement industry production scale becoming larger, the production equipment is becoming larger and larger, so the power of the drag motor required is also increasing
.
The production process of cement plant is more complicated, and the cement production process can be summarized as raw meal preparation (first mill), clinker calcination (first burning), cement grinding (second milling).

Therefore, low-voltage motor as a commonly used unit in the cement production process, a large number, complex types, with the continuous progress of science and technology and the continuous improvement of the process control process, especially to meet the requirements of automated production, it is urgent to develop and improve the control and protection equipment of the motor, to achieve the entire automated production process and large mechanical equipment remote control, telemetry, remote adjustment, fault diagnosis and centralized control and other functions
。 Cement production is a relatively large project, the production environment is relatively bad, dust pollution is serious, limited by the production process makes the ventilation conditions of the workplace poor and the ambient temperature is high, and it is necessary to set a large number of work stations, including raw material control station, crushing station, raw material grinding station, clinker warehouse control station, cement grinding control station, cement packaging control station, etc.
, but a large number of low-voltage motors are used in these stations to control the operation of other equipment, using simple voltmeters, ammeters, Electric energy meters and frequency meters are constrained by various conditions such as inflexible communication functions and single instrument functions, and can no longer meet the requirements of automatic production of
power plant equipment.
The production process of the cement industry is characterized by long-term operation, once started, under the premise of no special circumstances, it will generally not stop
.
Modern large-scale cement enterprises have a high annual operation rate, so it is necessary to have high-quality, high-reliability electrical equipment to ensure the continuity of their production process, once the failure and shutdown will cause huge economic losses
.
Intelligent motor protector can realize heavy load starting, realize the temperature protection of the motor, but also provide a variety of measurement and control functions and control modes, can meet the cement production process for the protection of motor equipment and its control requirements, not only can improve the operating capacity of motor equipment, extend the service life of motor equipment, but also improve enterprise production efficiency, save energy
.
This article introduces the practical application of ARD2F intelligent motor protector in cement production
.
Second, cement production on the function of the protector requirements cement industry motor is large-capacity, high-load continuous operation equipment, the motor long-term bearing large load, will make the winding temperature rise too high and reduce the insulation performance or even damage the insulation, shorten the service life of the motor, therefore, the cement production process of the reliability, stability and function requirements of the motor equipment are very high
。 In the process of production operation or equipment maintenance, common motor failures can be divided into the following types: 1.
Mechanical failure 1) Sweeping: due to bearing damage, shaft bending or improper assembly by maintenance personnel, resulting in friction between the stator and rotor; 2) Bearing damage: due to improper bearing assembly, axial misalignment of the stator / rotor core or insufficient accuracy after re-machining of the rotating shaft, the operating temperature rise of the motor body is too high, etc.
; 3) Vibration: due to poor motor itself or transmission device, etc
.
2.
Electrical fault 1) Phase loss operation: The current when the motor is locked is much larger than the current of normal operation
.
In this case, running time too long or starting too frequently will cause the motor winding to burn; 2) Winding short circuit or grounding: The cause of the inter-turn short circuit is caused by the abnormal increase in the temperature of the motor, and the ground fault is mostly due to the damage of the winding insulation; 3) Three-phase current imbalance: due to the imbalance of the external power supply voltage of the motor or the short circuit between the turns of the internal winding or the wrong number of coil turns or wiring errors
during motor maintenance 。 Therefore, it is necessary to carry out effective maintenance of a cement plant motor equipment, and the specific functional requirements for ARD2F intelligent motor protector are as follows: (1) The perfect motor protection function protector collects three-phase AC current, three-phase AC voltage, residual current, PTC thermal resistance value, motor energy and other power parameters in the circuit, as well as various motion states during motor operation, etc.
, and is processed and calculated by the protector's internal processing, so as to realize the overload counter-time limit, overload fixed time limit, grounding, Starting timeout, leakage, underload, phase failure, locked rotor, blockage, short circuit, overflow, unbalance (current, voltage), overpower, underpower, overvoltage, undervoltage, phase sequence, temperature, tE time, external fault, starting number limit, running time alarm, fault number alarm and other comprehensive protection, so as to ensure the safe and continuous operation
of cement plant production work 。 (2) Timely elimination of motor operation fault function Cement production site motor operation process through the motor protector to detect the motor equipment, when the motor appears in the condition should be timely alarm, and record the fault information, convenient maintenance personnel to find the cause of the fault and make timely treatment
, to ensure the reliability and sensitivity of the motor equipment action when the fault occurs 。 (3) Remote monitoring function of various equipment on site Cement production site environment is relatively harsh, protector not only to provide the protection function of motor equipment, but also to be able to bring RS-485 communication interface, through Modbus-RTU/Profibus-DP communication protocol and the upper computer management system for communication connection, to achieve real-time monitoring of the motor operating status and power parameters during operation, to ensure that the background operator can read, Modify the various tuning parameters of the motor protector on site of cement production and observe the working status of the current field motor control loop and the quality of power supply in real time through the background man-machine interface, so as to realize remote real-time monitoring
of the production site equipment.
Third, Accuray motor protector in cement plant application cases cement production process is more, so the protector is effectively applied to the motor protection equipment control loop while meeting the requirements of the large-scale control system of
the cement plant 。 A cement plant control system through the Profibus DP communication interface with PC, contactor, motor and other equipment to form a control system, engineers through the monitoring computer and production management software to complete the data collection, processing, display and monitoring of the entire system equipment, and meet the authority and logic, through the remote control software to achieve the control
of the corresponding motor equipment on site 。 Figure 1 On-site installation photo The cement plant uses protectors for motor protection control loops, replaces thermal relays as overload protection and control components of motors, and uses communication technology to realize the automation
of motor equipment control in cement production.
By embedding the 90L display module in the movable panel of the switch drawer, the wiring in the control cabinet of the cement plant is simplified, so that the operation and fault status of the equipment in the power distribution room are clearly visible, and it is convenient for engineers to adjust the system, set parameters and display, monitor and repair and maintain
at any time.
The ARD2F protector is applied to the control loop of the motor equipment of a cement plant production line to realize the requirements of motor protection in
the cement plant.
Figure 2 is the working principle diagram of ARD2F intelligent motor protector applied to the control loop of motor equipment in a cement plant: Figure 2 ARD2F intelligent motor protector applied to a cement plant motor equipment control loop wiring diagram Because modern cement factories use more large motor equipment, motors greater than 110KW and above are equipped with current transformers
in the main circuit 。 Considering the different cement production processes and the investment of enterprises, the motor needs different starting methods, ARD2F intelligent motor protector provides flexible interlocking functions to realize direct start, two-way start, star/delta start, autotransformer start, etc.
, so that the motor of large equipment in cement plant has been effectively protected and controlled [2]
.
4.
ARD2F product introduction ARD2F intelligent motor protector is suitable for low-voltage motor circuits with rated voltage to 660V, integrating protection, measurement, control, communication, and operation and maintenance
.
Its perfect protection function ensures the safe operation of the motor, with logic programmable functions, which can meet a variety of control methods
.
Different communication modules can be selected to meet the needs of
field communication.
The product adopts a split structure, which is composed of the main body, the display unit and the instrument transformer, which can adapt to the installation
of various cabinets.
Technical parameter function features ■ Support fundamental and full-wave power parameter measurement (U, I, P, Q, S, PF, F, EP, EQ), current and current imbalance, current positive sequence, negative sequence, zero sequence component, voltage, three-phase voltage phase angle, residual current
.
■ Protection functions include overload reverse time limit, overload time limit, grounding, starting timeout, leakage, underload, phase failure, locked rotor, blocking, short circuit, overflow, unbalance (current, voltage), overpower, underpower, overvoltage, undervoltage, phase sequence, temperature, tE time, external fault, starting number limit, running time alarm, fault number alarm
.
■ 9 programmable DI inputs, built-in DC24V power supply by default, external active wet contacts
can also be selected.
■ 5 programmable DO outputs, to meet the direct start, star-delta start, autotransformer start, and other starting modes, through the communication bus to realize the main station to the motor remote control "start/stop"
.
■ Optional anti-shaking function: support shaking immediatelyStart again, lose pressure and start again
.
■ Optional MODBUS_RTU communication, PROFIBUS DP communication, support 2-way communication interface
.
■ Optional 1 channel DC4-20mA analog output interface, connected with DCS system, can realize the monitoring
of field devices.
■ It has various event records
such as fault record, start record, stop record, DI shift record and restart start record.
■ LCD display interface, support Chinese/English switching
.
V.
Conclusion With the continuous development of
electronic technology and communication technology.
Motor protector is also developing in the direction of diversification, motor protector in cement enterprises is more and more widely used, reasonable selection of motor equipment protection function and protection mode, can improve the reliability of equipment operation, can prevent and eliminate motor burning, while reducing the loss caused by unplanned shutdown, reduce the production cost
of enterprises 。 References:[1] Accuray Enterprise Microgrid Design and Application Handbook.
2022.
01 Edition.
[2] GB 14048.
4-2020 Low-voltage switchgear and control equipment Part 4-1: Contactors and motor starters Electromechanical contactors and motor starters (including motor protectors).
[3] Yang Jianhua, Liu Wei.
Application of motor protector in cement industry.
Cement Technology.
2009(05)About author:Ren Yunye, male, Ankrui Electric Co.
, Ltd.
, the main research direction is low-voltage protection measurement and control
.