VVVF Power Supply Designation Based On DSP

Nowadays Variable-Frequency Inverters which are being used in many fields play an important role in the life. The merits of digital control: simple hardware, no temperature drift, flexible control and easy to realize advanced arithmetic etc, make digital control technique to be used in power supply manufacture to let it be more credible and easier to realize in batches with lower costs. In the current it is popular to use digital control in power design.This thesis presents the total project to design the VWF power supply based on DSP. First it summarizes the control method of the inverter and the characteristics of the digital control. It discusses the two-order LC filter designation based on the distribution of the harmonics using SPWM and the influence of the different of LC filter parameter on the THD of the output and the current stress. In addition, the influence which is brought by the Dead-Time of the output have been discussed. In order to get good dynamic as well as static performance, multiple-loop control strategy with the average voltage outer loop and the instantaneous voltage inner loop is used in VWF inverter based on DSP TMS320F240. How to get the control parameters is analyzed in details. In the end the experimental results are displayed.