| Multilevel inverters are very suitable for high-voltage and high-power conversion applications, for they have the advantages such as low voltage stresses for power devices and absence of voltage evenness of power devices compared with the topology of series connection. And the space voltage vector control of induction motors has been widely used in recent years because of its simple methods and high stable/transient performance.This thesis comprehensively describes the development future and the present development condition of multilevel inverter. And then present the development of space voltage vector control algorithms for induction motors fed by three-level diode-clamped inverter (neutral-point clamped, NPC) .On the basis of theory of vector control, this thesis systemeticly analyses the inherent property of three-level inner vetors. and then introduce the application of unified voltage modulation thechnique in two-level inverter. After the application of the thechnique in two-level inverter is translated into in three-level inverter. SVPWM algorithm of three-level inverter is educed. Based on the algorithm,a neutral point balancing and narrow pulse elimination algorithm with dead time compensation is proposed.Finally, this thesis simulates algorithm proposed with MATLAB. TMS320LF2812DSP is choosed as the main controller to complete system software. With the algorithm ,waveform, which verify the proposed algorithm, was achieved on three-level inverter. |
