With the improvement of industrial automation level and the increase of motor applications in various industries, the increase of single-unit capacity, this large number of motors can be divided into 10kV motor, 6kV motor, 380V motor according to voltage level, which can be divided into 1 according to importance. Class load, class 2 load, class 3 load, Pipe Sphere,Stainless Less Pipe Sphere,Floating Welded Ball Valve,Stainless Steel Ball Valve Antong Valve Co.,Ltd , https://www.atvalveball.com
Ankerui Chen Jingyan
Jiangsu Ankerui Electric Manufacturing Co., Ltd. Jiangyin, Jiangsu 214405, China
Abstract: This paper introduces the ARD intelligent motor controller of Ankerui Electric Co., Ltd., the latest solution for low-voltage motor control, protection, measurement, communication, etc., for reference in engineering design.
Keywords: low-voltage motor intelligent control protection measurement communication field bus-ARD intelligent motor controller application in industrial production process control
I. Overview:
With the improvement of industrial automation level and the increase of motor applications in various industries, the increase of single-unit capacity, this large number of motors can be divided into 10kV motor, 6kV motor, 380V motor according to voltage level, which can be divided into 1 according to importance. Class load, class 2 load, and class 3 load can be classified into large motors, medium motors, and small motors according to capacity. Application of -ARD intelligent motor controller in industrial production process control
Simply relying on the DCS system, or the PLC control system, can only complete the basic control functions of the motor, and its functions of protection, measurement, tuning, fault recording and so on rely on a large number of other peripheral devices to complete, with the development of microcomputer communication technology. The integrated automation device that integrates centralized control, protection, measurement and communication functions with distributed and distributed structure will be the future development direction. Application of -ARD intelligent motor controller in industrial production process control
The reliability and safety of the microcomputer-based intelligent protection equipment are constantly improving, its functions are more perfect, and its application is more extensive. It is marked by the introduction of low-voltage motor comprehensive protection and control equipment by famous foreign electric companies, and a new low-voltage motor control. Protection solutions were born, more representative: Alstom, Rockwell, Toshiba, Siemens. ARD motor protector is a motor intelligent protection control unit with international level at home, which is representative in China.
In the motor control, ARD replaces many complicated secondary wirings in the traditional scheme, and only requires a contactor to complete a variety of operations and a large number of protection communication functions.
The operation functions include: direct start, two-way start, star-delta start, stop and other functions, which can be programmed to operate locally or set to remote control. In addition, the “three remote†measurement and control of the circuit breaker can be realized by the programmer.
The protection functions include: overload inverse time limit (multiple grade curves are optional), overcurrent, leakage grounding, undercurrent, three-phase unbalance, thermal protection, contactor pickup state detection, start timeout, undervoltage protection, etc.
Monitoring function: three-phase running current display, motor starting current display.
Maintenance functions: functions such as number of starts, running time, contactor failure, historical fault information, and alarm information display.
Communication function: With RS485 interface, it can be connected to PROFIBUS field bus and MODBUS field bus. The "four remote" function can be realized.
Second, the outstanding advantages of ARD series motor protectors
ARD motor protector is a relatively influential product in China. Nowadays, from the design, installation, commissioning to commissioning of the motor feeder protection control system, the cycle is getting shorter and shorter, and the requirements for the device are increasing. This requires the system to be compact, intelligent and powerful. Each motor is optimally protected and the wiring is as simple as possible. ARD is based on the above requirements.
1.1ARD itself has the functions of normal direct start, two-way start, star-delta start, stop, etc. It can also be programmed to operate locally or remotely through a programmer. The complicated secondary wiring in the traditional scheme, such as: start and stop logic circuit, electrical interlock logic circuit, can be canceled, all logic of ARD is completed by the chip, which greatly reduces the wiring cost.
1.2 The protection function is more perfect, which causes many reasons for overload of the motor, such as load overload, phase failure, rotor stall, and start timeout. The device can correctly judge and protect against the above faults. In addition to overload, overcurrent, undercurrent, and leakage fault protection, ARD can also realize three-phase current imbalance, motor phase failure protection, overheat protection and ground fault monitoring. The device parameters can be set by the programmer. Elimination of traditional functions, single-structure complex thermal relays, ammeters, transformers, transmitters, I/O modules, large melting point operation buttons, and secondary relays and cables.
1.3 With the operation display module, it has the display function of current, fault category, starting current, starting time and operation times. The ARD display module can perform various operations such as setting settings, performance testing, and fault finding. Through the serial interface, the connection with the fieldbus system realizes communication networking and bus control.
1.4 Small size and flexible installation. The ARD can be used with the display module or it can be used separately. It can be installed horizontally or vertically. The volume of the ARD is 81.5×90×86, and the whole volume is only about one contactor.
In short, ARD replaces the traditional wiring, which not only saves components, but also reduces the total investment cost, and greatly improves the reliability and automation level of motor control. (See the comparison between the traditional scheme and the ARD scheme in Figure 1 and Figure 2 below) 
Figure 1 Traditional scheme 
Figure 2 ARD motor protection scheme
Third, advanced control unit
There are two major parts of the hardware circuit. The core component of the motor controller is MCF51EM256, which mainly completes data acquisition, data processing and various control and protection functions. The core components of PROFIBUS-DP interface are VPC3 and 12C5A, and SPC3 is a dedicated protocol chip for PROFIBUS-DP. It is responsible for unpacking the data sent from the main station and sending it to 12C5A. At the same time, the data from 12C5A is packaged and uploaded to the main station. 12C5A is the bridge between MCF51EM256 and VPC3. It is responsible for transmitting the data sent by MCF51EM256 to VPC3, and transmitting the data after unpacking VPC3 to MCF51EM256. The RS485 serial interface is used to exchange data between the motor controller and the PROFIBUS-DP interface (the communication protocol satisfies MODBUS). The motor controller and the PROFIBUS-DP interface are two relatively independent modules. If no network is required, this function can be omitted. This can reduce the cost of the product. 
Figure 3 ARD schematic
Fourth, simple and quick operation function
ARD has a wide range of control functions, it can be used as a motor direct starter, bidirectional starter, star triangle starter, and also as a variable level switch, solenoid valve starter.
Since the device is actually a distributed and distributed low-voltage motor intelligent control and protection system, it still maintains relative independence with other control systems (such as DCS systems), when the upper-level control system or communication system fails. It can automatically switch to manual mode to control the outage or continue operation of the load, and at this time, the possibility of continuous operation of the motor protected by the device is greatly enhanced.
According to the secondary line of the motor made by ARD, compared with the traditional secondary line, we will find that under the requirements of various conditions, the secondary control loop becomes simple and standard, which makes us completely get rid of the original A lot of backward relays have brought us troubles, and the design is more convenient at one time. With the operation display module, various measurement, display and operation functions are completed.
ARD can use the defined control functions and basic chain requirements to complete some of our common motor control, minimize the workload of program input, reduce the possibility of errors, shorten the cycle time of the program, and better guarantee Reliability, while reducing the workload of our secondary design to a greater extent.
The device can protect and continuously monitor the ground fault of the motor. For the three-wire type motor, it can be grounded by the ground fault detection device inside the device. In addition, it can be accurately measured by connecting an external vector and current transformer. The ground fault current is achieved by comparing the set currents to achieve motor stall protection.
V. New application examples
The ARD intelligent motor controller is flexible in application, communication and display modes are optional, but the basic operational protection functions are not changed.
5.1 stand-alone operation application
In a decentralized working environment, a large number of single motors are operated in industrial production. These motors do not require communication functions, and only require reliable start, stop, fault protection, fault analysis, and operating parameter viewing. The above functions can be realized at a very low cost. The wiring diagram is as follows:
a) Direct start wiring 
Figure 4
b) Two-way starting wiring method
ARD outputs two contacts, controlling the forward and reverse of the motor by controlling two contactors, and also selecting the optocoupler contact input for remote control 
Figure 5
c) Star-delta start wiring
The ARD outputs two contacts, and three contactors are controlled by timing to form a star-delta starting mode, and the timing of the star-delta starting can be set. 
Figure 6
d) Outbound measurement and control application
By combining with the circuit breaker, the "three remotes" can monitor the three-phase current and the switching state of the circuit breaker, and the circuit breaker can be combined and operated by the level mode and the pulse mode. 
Figure 7
5.2 bus networking MMC motor control center
The MCC Motor Control Center is the place where ARD can best demonstrate its advantages. It can centrally control the motor through networking, and realize the connection with the fieldbus system through the serial interface. It can be controlled by communication network through PROFIBUS or MODBUS protocol. The center can collect the current operating parameters of each motor, and also can realize the logical operation control of all the motors through the configuration software of the upper computer, realize the engineer workstation, and realize the unattended operation of the motor control center.
ARD has a compact structure. It can be installed in a 1/4 drawer cabinet for ARD motor controllers up to 100A, and ARD can be installed in 1/2 drawer cabinets under 820A. The intelligent low voltage with communication function of the above equipment is available. The switchgear can integrate all control protection, measurement, communication and functions in one drawer unit, so that the entire control system of the design is very connected to each other, saving the wiring cost between the control level and the field.
The development of the drawer type switchgear is inevitable. The application of the ARD intelligent controller in the MCC control center makes the secondary wiring simpler and cheaper. At the same time, the reliability and automation level of the control loop are improved. At present, because the application of electric motors involves power generation, chemical industry, environmental protection and other industrial sites, ARD can exert its advantages of intelligent control in these places.
ARD can realize the connection with the fieldbus system through the serial interface, and realize the “four remote†monitoring and management through the communication network.
The bus system structure is divided into two types as follows:
(1) System structure diagram: 
Figure 8 
Figure 9
Figure 8 structure can be selected by MODBUS or PROFIBUS for data transmission. When ARDBUS controller is used, N can be up to 255 stations. When PROFIBUS is selected, N can use up to 127 stations, but every 31 A relay is required between the slaves.
The structure of Figure 9 uses the DP protocol gateway for data transmission. Up to 127 × 32 slave stations can be connected due to the gateway. In the figure, the main station can select industrial computer, PLC, HMI, etc. according to the needs. The transmission medium can be selected according to engineering requirements: shielded twisted pair, optical fiber, wireless transmission or power carrier.
ARD can use PROFIBUS or low-cost MODBUS fieldbus networking. In industrial control systems, we can form high-performance communication between the local ARD motor control protector and the superior DCS system. All control commands and operating data are available. It can be transmitted through shielded twisted pair and fiberglass cable, so that we can save a large amount of contact cable from the local to the control room while ensuring accurate, rapid transmission and long transmission distance.
Sixth, ARD motor protector selection
The ARD2F model is as follows:
1. The ARD2F model is as follows: 
Figure 10 ARD2F Model Description
Table 1 rated current 0
Table 2 Additional notes for rated current 1
Note: Table 2 data is applicable to AC400V, 50Hz, 1500 rpm four-pole squirrel cage motor
Table 3 additional function code 2
Note: 1. With start control, the protector provides up to 2 start relays for sequentially controlling the closing/opening of the external 2 contactors, thus realizing different starting modes of the motor (such as Y-∆ conversion start, positive and negative Transfer control, auto-coupled step-down start, etc.);
2, the temperature protection measurement range: thermal resistance 100Ω ~ 30kΩ;
3. For customers without display requirements, a 90FL display unit must be ordered in a batch of orders for debugging purposes.
Table 4 shows the way 3
Seven, the conclusion
In summary, for the industrial production of low-voltage motor control and protection system, it provides a brand-new concept, the complete protection and monitoring of the motor can be realized through ARD, and the “three remote†measurement and control of other powers can be realized. No additional protection and control equipment is required. Therefore, the total investment cost is reduced, and the reliability and automation level of motor control are greatly improved. The promotion and application of the new motor control protection scheme is an inevitable trend.
references:
"Application of ST500 Motor Intelligent Controller in Industrial Process Control"
"Development of Fieldbus Technology and Its Application in Switchgear"
"Intelligent low-voltage electronic control power distribution system at home and abroad"
"Intelligent Motor Controller with PROFIBUS-DP Interface" 4http://news.chinawj.com.cn 
Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn