Research Of Electronic-Hydraulic Servo System Based On PWM Control

In this paper, study the Electronic-Hydraulic Servo System based on PWM control, which use the modem theory and simulation technology. And use the Strip Steel Rectifying Control System for reference model. Make optimize design and experiences for the system, bring some methods to improve the structure of the electromagnetic iron and the capability of the Electronic-Hydraulic System.Study the high speed on/off value which used in the Electronic-Hydraulic System based on PWM control, Because there are some requests of the digital valve such as magnetic force, it needs to redesign the structure of the electromagnetic iron which used in the digital valve. It is optimized through the finite element analysis. Study the PWM control theory, perform the Electronic-Hydraulic System simulation, found some relationship between the rectifying precision and duty cycle frequency of the PWM signal magnetic force.Too much or too less of the duty cycle will cause the decrease of the rectifying precision; If the frequency of the PWM signal increase, the rectifying precision will also increase. But there exist a critical point. If past this point, the response time will increase. Similar to frequency of the PWM signal, the Strip Steel Rectifying Control System have particular need with the magnetic force. But when the magnetic force value is strong enough, increased of the force value will useless for improvement of the system.In practice, confirm the results of the analysis and simulation through experiences. Compared with the Rectifying Control System using servo value, it is better for the Rectifying Control System using digital value. High response stabilities anti-pollution and lower prices, will make this new kind of Electronic-Hydraulic System using PWM control more and more popular.