The Research On Variable Frequency Motor Driver With PC For CNC

This paper has a research on the theory of high-capability Variable Voltage Variable Frequency (VVVF), and an Application Specified Integrated Circuit (ASIC) SA4828, MCUAT89C51 and Intelligent Power Module (IPM) 7MBP75RA120 are adopted in this paper, which is a low-cost, high-capability VVVF motor drive.The applied characteristics of SA4828 IC are expounded in the paper, the circuit engendering warmform is easy to design, and it's convenient to program for control. And the Intelligent Power Module (IPM) 7MBP75RA120's characteristic and self-protection function are studied as well, credible and steady driving circuits for IPM have been designed. To adapt to the requirement of control with computer, the communication between transducer and computer is designed in this paper, so that the PC can conmunicate with the transducer. In order to design a credible andsteady system, the function of Over-voltage , Under-Voltage , Clip Current star-up , Over-Current and Over-Load protection have been designed in the paper; some methods of anti-disturbance from the aspect of hardware and software are expounded; the system's malfunction program is convenient to detect and solve problem. The design realizes the basic function, assistant function and special function of the transducer.The inverter's hardware and software is analyzed in detail, the circuit diagram and progress of software model are introduced.This system is controlled by SPWM controlling technology, furthermore ithas many operating and protecting functions. At the same time, it is very convenient to input parameters or change the drive's operating mode due to the advanced human-machine interface. The model power switch is adopted to decrease the malfunction and the cost of single transducer, moreover, the new integrated parts and well-rounded control arithmetic make the transducer cost less time to be developed and which has a very low cost, simple structure with stable operational capability.