Design For PLC Control System On The Digital Testing Platform Of Motors And Transformers

Rapid progress in networking,computers and other digital technologies have profoundly impacted on industrial production,automation has become one of the hallmarks of modern industrial production.Extensive use of digital technologies in field of motor-testing have changed the mode of production in this field a lot.This paper describes the testing-system under an example of motor-testing,and can be used for transformer-testing.The paper briefly describes the technological developments in the field of motor-testing,according to the actual situation analysis of all possible programs,the overall framework of the finally selected program is introduced,and gives a brief description of role of each part in the framework.And then analysis detailed the design of PLC control system which is divided into two parts——hardware and software.The hardware part gives the reason of choosing Siemens CPU module as the processor of PLC control system,and then based on this CPU,selected other modules,including power module,I/O module,communication module and interface module,also determined inverters and DC motor speed-control-devices which directly control motors and constructed a single-master mode control network including these electrical equipment with Profibus-DP protocol. The software part including two parts——configuration and program.First describes the configuration on platform——STEP7,including setting parameters in for CPU and allocating I&Q addresses for all parts of control system in memory area of CPU and IDs for devices in the DP network.In program part,first describes the role of Edit Symbol table,and then to 400KW converter test as an example analyses in detail the software design process,including the power supply part,the output part,the parameters setting of inverters and parts of handling emergency.System debugging part is divided into hardware and software corresponding.Finally summarizing the useful guide to the actual work of this article,and prospecting for the development in the future.