subject: Plc And Frequency Converter With Synchronous Control Crane Trolley [print this page] Abstract Article on multi- Motor Speed synchronization control of a brief analysis and a systematic introduction to PLC and frequency conversion technology in gantry Crane Application of synchronous operation control car and control the outcome.
Keywords Crane speed synchronization control PLC Converter
In the traditional transmission, the number of implementing agencies to ensure the speed synchronization control, often connected by rigid mechanical drive unit to achieve. But when the input power requirements of the implementing agencies large or the distance between the implementing agencies, the independent control can only consider the transmission of non-rigid connection means that the multi-motor synchronous drive. However, synchronous drive system, because the system is affected by many factors, all parts will have different degrees of volatility, speed deviation from the normal value, resulting in the system are not synchronized. This can range from damage to the device, while in causing Personal safety Accident. Synchronous speed control so practical engineering significance. Here we introduce a more advanced synchronization control method, namely the use of PLC and frequency converter speed synchronization between the two devices.
1 of the problem Gantry cranes operating devices were powered by high-power AC motor drive, run devices Electric motor Through the coupling, reducer drive shaft and wheels, so that along the orbit. Manipulation to the entire crane gantry crane running along the track known as the cart to run some institutions. Also, make crab laid in the main beam along the orbit is known as trolley body parts. If the larger tonnage of car lifting, must use two four-wheel drive car, can be used both on the track on both sides, into the diagonal layout of the motor drive (Figure 1). However, the two transmission connection is not rigid, when the system start, or transmission gap inequality, when the brakes are different elastic adjustment will result in two active wheel speed can not be synchronized, Er Shi body to reverse, resulting in "derailment" phenomenon seriously affects the safe use of cranes and may even result in the risk of derailment.
2 Implementation Order to achieve the two speed synchronous traction motor, the inverter can be used two YZR160M1-6/7.5kW traction motor, then use converter for speed control, and then PLC direct control of the two inverter .
In the closed-loop control to the speed of a traction motor target speed, the traction motor inverter 2 to adjust its speed to track the speed of traction motor 1. The two incremental rotary encoders and motor coaxial connection. Then the encoder 1 and encoder 2 were collected from the two motor speed pulse signal, and sent to the PLC high speed counter mouth or connected to the CPU, IR00000 ~ IR00003. These two speed signals control the amount of data as input, for the ratio?? Integral (PI) control algorithms, computational results as the output of analog signal service module PLC to control the traction motor inverter 2. Therefore, we can ensure the speed of traction motor 2, a traction motor speed to track changes in change. To keep pace and avoid the two speed "crawl track" phenomenon.
Collected from the pulse encoder signals into motor speed data, after the next treatment after storage in a DM area, as computing the Y value. After calculating the P value, sent to analog output channel, through upper and lower limits, after calibration, converted into frequency converter can accept current or voltage signal to control inverter traction motor 2.
In addition, the work site there are several sets of high power cart drive motor. Therefore, in order to reduce power supply system caused by external factors, such as interference, we designed the PI control algorithm, we must consider using integral part of I to eliminate the accumulated error. Thus, a traction motor and traction motor 2 can be good for high precision synchronization and synchronization to ensure the stability of running organizations.
3 Control result Compiled PLC PC using VB Monitor Program, acquisition speed value and draw curves, data extraction time interval 15ms. Figure 4 is the speed of traction motor and traction motor 1, 2, the relationship between the speed curve. Curve with the car running in real time changes. In fact a traction motor and traction motor 2 speed is the same, but in order to reflect the traction motor 2, the tracking and volatility, we are conscious of their separation, the above is the traction motor speed curve 1, the following is the traction motor 2 speed curve .
The speed of a traction motor change, the traction motor 2 will be able to respond in a timely manner, tracked, and achieve stability soon. Experiments show that the PLC and inverter control method can achieve high synchronization requirements, fast response speed of less volatile.
4 Conclusion
This control scheme has been designed in the 40-ton gantry crane to get application. From the operation point of view, obvious effect car starting synchronization, run smooth, essentially overcoming the "climb-rail" phenomenon. With the variable frequency technology to expand the scope of the use of PLC technology to control, will better improve the transmission speed control on the reliability and flexibility. Comment Large In Small
Plc And Frequency Converter With Synchronous Control Crane Trolley
