"基于PLC和变频器的桥式起重机控制系统改进设计"

The improved design of bridge crane control system based on PLC and frequency converter is discussed in this paper. The practical applications of AC bridge cranes and the determination of PLC in the transformation scheme are elaborated, and the selection of equipment in the transformation process is also involved. Taking Siemens S7-200 series PLC as an example, this paper describes the control scheme of PLC in the transformation of AC bridge crane. Compared with traditional control schemes, bridge cranes controlled by PLC can simplify complex equipment and make the control more safe and reliable. From the perspective of economic and environmental benefits, although this design requires a certain amount of capital investment to purchase PLC and frequency converter equipment, the long-term maintenance cost of the system after operation is much lower than that of the original system, and the energy saving can reach about 30%. In the design, the frequency converter is controlled by PLC without contact, which makes the equipment operation more accurate and reduces the labor intensity of personnel, thus improving work efficiency. Keywords: bridge crane, frequency converter, PLC control system