Sinamics S120 is a new drive and control system introduced by Siemens. It can be used to control many types of motors.
Its speed regulation function is accurate and reliable. Its powerful positioning function can also realize the absolute and relative positioning of the feed shaft. Siemens S120 single axis controller is applied to the integral belt scale of non-woven equipment, which improves the accuracy and reliability of material conveying belt speed regulation. This paper introduces the specific scheme of the realization of the control function, and describes in detail the configuration of the whole electrical hardware, the debugging of the servo motor and the compilation of the control program. On the premise of the development of frequency conversion technology, the current loop, speed loop and position loop inside the servo driver all carry out more precise control technology and arithmetic operation than the general frequency conversion, and are much stronger than the traditional frequency conversion control in function. The voltage signal is converted into torque and speed to drive the control object, and the position is realized. Closed-loop control of speed and moment can respond to instructions quickly, accelerate and decelerate faster and more efficiently. The main point is that position can be accurately controlled.
At present, servo control function has been widely used in all kinds of pipeline equipment, which can make the control system achieve a new level of performance, including more accurate speed regulation and positioning, thermostatic element higher productivity, better reliability and longer life compared with the previous frequency conversion control.
In this paper, the application of Siemens S120 single axis controller in the integral belt scale of non-woven production line is taken as an example to illustrate its specific implementation process. SINAMICS S120 is a new drive and control system of Siemens, which integrates V/F, vector control and servo control. It can not only control ordinary three-phase asynchronous motor, but also control synchronous motor, torque motor and linear motor. SINAMICS S120 has modular design, can provide high-performance single-axis and dual-axis drive, power range of 0.12 kW-4500 kW, has a wide range of industrial application value. Because of its high flexibility, SINAMICS S120 can perfectly meet the increasing demand for the number and performance of drive system shafts in applications. Here, the S120 single-axis controller applied on the integral belt scale makes use of its precise and reliable speed regulation function and powerful positioning function.
The electric control system of integral belt weigher is controlled by Siemens CU310-2PN single-axis controller, S7-1200 programmable controller and KTP700PN touch screen. Siemens CU310-2PN is a single-axis control unit, which is configured on the power module to provide communication and open-loop/closed-loop control functions. The S7-1200 programmable controller consists of a 1215C module with 14 digital inputs, 10 digital outputs, 2 analog inputs and 2 analog outputs. KTP700PN touch screen, as a new generation of Simens compact panel, is a 7-inch touch-plus-key type touch screen with PROFINET communication. In order to improve the accuracy of the grammer calibration, we use the Gemman GM series weighing instrument with the weighing sensor to detect the material weight on the calibrated weighing rod. The starting and stopping of integral belt weigher are controlled by the feeding start signal given by the lower carding equipment. After the feeding start signal of the lower carding equipment arrives, the belt weigher and its self-leveling function can start. Belt scales are calibrated by weighing instruments equipped with weighing sensors. According to the requirements of field production, the set weight is compared with the actual weight. The speed of entering the feeding point is adjusted by the algorithm in the PLC programmable controller.
When the weight of the raw material on the weighing stalk becomes lighter, the speed increases at the feeding point; when the speed ratio increases, the speed increases at the feeding point; when the weight and speed ratio decreases, the reverse is true. Based on the above control process, we write the PLC program and set up the equipment configuration by Siemens Botu V13 software. After the successful communication of PRIFINET, we can debug the relevant PLC program. Between Siemens S-1200 PLC and CU310-2PN unit, periodic and non-periodic data communication can be carried out through PROFINET IO.
Using S7 function blocks DPWR_DAT and DPRD_DAT, S7-1200 PLC can send control words and main setting values to the driver through PROFINET periodic communication mode, and read status words and actual values from the driver. After debugging the PLC control program, we need to debug the servo motor. Here we use Siemens SCOUT4.5 software to debug the S120 servo controller. The CU310-2PN driver uses PROFINET communication mode. When the network communication is normal, the SCOUT 4.5 software can be opened to configure the communication parameters, and then the driver can be read automatically through the “Automatic Configuration” function on the software side. The motor parameters can be set after the reading of the driving device.
Because the belt weighing equipment uses the third-party motor (non-Siemens motor) and encoder, the basic parameters of the motor and encoder need to be manually configured, and the initial phase angle of the motor needs to be identified.
After identifying the initial phase angle of the motor successfully, open the “Control Panel” control panel on the software side to apply power to the motor, and the writing speed can rotate. In order to improve the accuracy and reliability of motor operation, reduce the motor jitter and overcome the motor whistle while speeding up the response, the coefficient of current loop and speed loop can be adjusted manually by observing the motor motion curve through the “Trace” function provided by the software side. In addition, the slightly higher version of S120 also provides automatic optimization function. Select the “Automatic controller set” function option on the software side. Through the automatic optimization function, current loop can be automatically identified, positive and negative load measurement, and speed loop parameters can be automatically set.
After automatic optimization, the system can meet the dynamic requirements of general servo control occasions. Through the above operation, the adjustment of the belt scale servo motor is completed. At present, servo control has been widely used in all kinds of pipeline production equipment, which improves the control system of the equipment to a higher level, more reliable and efficient, and has better expansibility and openness. Siemens S120 single axis controller is applied to the integral belt scale of non-woven equipment, which improves the accuracy and reliability of material conveying belt speed regulation. Compared with the frequency conversion control used before, the actual weight of material conveyed by the belt weighing equipment is more consistent with the set value, which improves the productivity, stability and reliability of the equipment.