The Research On Series Resonant Frequency Control System Based On DSP

Nowadays, with the rapid development of society, more and more attention has been paid to the reliability of electric power system. XLPE cables which require pressure testing of the cable field before put they into operation, in order to ensure safe operation. Large power supply and large transformer are needed to do isolation test for power cable if using 50Hz power supply. So other kinds of testers are researched to solve this problem. The series-resonant frequency technology which is most economic and easy to implement, recognized as the best choice.This thesis research is based on DSP digital control technology. First analyzed the DC voltage test and the traditional AC voltage withstand test in the power cable insulation testing in the advantages and disadvantages, and based on this, using the series-resonant frequency technology field AC voltage XLPE power cables can be realized. Through comparing the basic principle of each kind of SPWM, the unsymmetric rule sampling is chosen as the SPWM to output voltage and frequency that both can be regulated independently adjusted.According to the needs of the AC withstand voltage test, in this paper, design a hardware control system which used DSP and FPGA work together as the central processor. TMS320F2812 is used to make up the main controller in the control system. DSP is used to output SPWM which is used to control the inverter and voltage and frequency are both can be regulated independently. Also use the fault signal processing module to monitor the voltage and current signals all the time, protecting signals can be sent out while an abnormity being detected. The second part of the control system is HCI(human-computer interaction)control unit which use FPGA to make up for it. The HCI control is used for displayed test information on the LCD screen immediately and exchange information between DSP and FPGA. In this thesis shows a series-resonant frequency control system hardware design of each functional unit, finished the protracting of the whole principle chart and the facture of the PCB board. In the software part of the control system, described the preliminary design and software structure diagram, analyzes the working process of software.At last, analyzed and summarized the work, puts forward areas that need to improvement.