Research And Design For Three-phase Three-level Inverter Based On DSP Control

With the rapid development of power electronic technology and control of the chipconstantly update, multilevel power converter has received the widespread attention invarious application fields, especially in high voltage high power and new energy powergeneration which areas need higher requirements to the control voltage precision.Because itsless harmonic content, low voltage stress, small switch loss and it can use low pressure powertube to realize high output voltage level three-level inverter received great attention.This paper studies the the present situation of the development about three-phasethree-level inverter at home and abroad, summarizes the three-level inverter developmentdirections, and analyzes the advantages and disadvantages about the different topology circuitand modulation method.This paper studies working principle of three-phase three-level NPCinverter, and then found that the new inverter can disperse loss of each power tube and savethe clamping diodes.Then improved space vector pulse width modulation algorithm, throughthe optimized algorithm which omitted a large number of trigonometry, it can save theresources of the processor.Then it analysis the partial pressure of capacitance voltage in thetwo kinds of inverter, and put forward a kind of by adjustment factor method to controlneutral voltage vector to maintain the stable operation of the inverter.In this paper, we respectively model the two kinds of inverter circuit with the improvedalgorithm, the results show that the algorithm is the feasibility in the two kinds of circuit.Then the method that add adjustment factor to control the neutral voltage are simulated, andprove the validity of the analysis, the simulation results proved that the theory is correct.The two kinds of inverter circuit and driver circuit also be designed in this paper, and thespace vector pulse width modulation algorithm is running in DSP, by comparing we found thenew special circuit topology greatly reduce drive power which saves the cost of the inverterand it is easy to design for heat dissipation.Finally the experimental results show that theoptimized pulse width modulation algorithm can perfect inverter in the two kinds of circuitwhich validate the theoretical research and hardware design are correct and reasonable.