Design Of Drive Power System Of Dual-ultrasonic Vibrator Compression Based On FPGA

As a kind of new energy, Cellulose fuel can be obtained by crushed and compressed crops straw, alleviating the crisis of the strain of China’s energy. Therefore cellulose fuel can not only meet the demand of the development of today’s society, but also can greatly reduce the air pollution index in our country. Due to imperfect traditional compression molding technologies, the size of compressed biomass briquette is too big, leading to high cost of transportation and storage, in order to solve this problem, this paper will install a synchronous vibration double ultrasonic oscillator compression system to minimize the volume of briquetting, using an ultrasonic power to drive two ultrasonic vibrators of the same or similar parameters at the same time, one of the ultrasonic vibrator can be moved, another ultrasonic oscillator is fixed on the workbench. The research of this system mainly includes the following contents:After analyzing the working principle of ultrasonic power, the scheme of the driving power supply of the double ultrasonic vibrator compression system is designed by using FPGA as the control core, and every modules of the power supply will be introduced in detail along with the corresponding circuit principle diagram. The double ultrasonic oscillator frequency tracking method of compressed drive power supply is the current and phase frequency tracking method.Then determining the matching of ultrasonic power supply network and giving detailed instructions of the matching network, designing the power of high frequency transformer and dynamic inductance parameter, and making high frequency transformer according to the designed parameters.Finally this system uses the current maximum frequency sweep variable step length and principle of phase difference as the method of frequency automatic tracking. What’s more, the A/D sampling module and the output power control module based on FPGA hardware and the human-computer interaction interface module including man-machine interface and communication protocol are designed. On the basis of secondary development of the FPGA core plate, this system also creates the Nios Ⅱ soft core and the SOPC system, making communication between FPGA and the touch screen more easy. After designing the PCB of drive power supply based on above modules and packing them, this paper test the power supply through the compression device under several experimental conditions:1, getting and comparing the volume of biomass briquette size under the conditions of no ultrasonic,single ultrasound and double ultrasound with different compression time;2, Analyzing the effect of double ultrasonic on the volume of briquetting under the different compression time and the input voltage and the process parameters using Orthogonal experimental analysis. The result of experiments proves that the double ultrasound is of great effect to reduce the volume of biomass briquette and also confirms that a ultrasonic power can drive two ultrasonic oscillator with good running state and frequency automatic tracking effect. So the system designed in paper meets the requirement of this subject well.