| As the developing of people's physical lives, personal fitness equipment become more and more popular. Running Machine as it is easy to use and easy to get enough exercise, people like it most. Now most of Running Machines are electromotion Running Machines and the direct current motor was widely used in the speed-adjustable systems. Along with the development of power electronics technology, AC motor for its maintenance-friendly, simple structure and other characteristics of being used to Running Machine speed-adjustable systems. Be regarded as the controller of the AC speed-adjustable system, Frequency Inverter is gaining more and more attention.In this paper, we designed a low-cost Frequency Inverter for Running Machines. The core of the Frequency Inverter is motor control ASIC MC68HC908MR8 of MOTOROLA Company. The control method is open-loop U/F control. We choose Mitsubishi's Intelligent Power Module (EPM) PS26514 as the power device of the inverter circuit. The driving method of the Intelligent Power Module is SPWM waveform modulation. We bring in voltage compensation to the frequency convert system, together with the function of operation control, parameter settings and integrated function of protection. Making the Frequency Inverter not only has a better control performance, but also has integrated safety guarantee. The digital control box has being specially designed so that the Frequency Inverter can be used as an adjunct of Running Machines and it also can be direct used as a controller of the Running Machines.The frequency convert system we designed in this paper has a good human-machine interface. It has good security and nicer control function. The Frequency Inverter is simple, easy to use. It is one kind of operation simple and convenient AC motor controller. The circuit of the Frequency Inverter has a lower cost, but it has a high availability. The design in this paper has achieved the basal function of the Frequency Inverter. |
PDF Full Text Request