A Novel Control Strategy Based On SVPWM For Three-Level Inverter

Recently, the research and design of three-level medium voltage frequency inverter has widely become the hotspot in the area of power drive. Three-level inverter makes a high-power voltage-source-inverter possible. Therefore, it is very important to study and design the three-level inverter both in the theory and in the practical application.This paper introduces work principle of two levels inverters principle of the voltage vector modulating technique, Based on this principle, the three-level inverters has been researched .In the same time, the basic principle of SVPWM of three-level inverter is studied and ameliorated. This paper introduces the estimation method of the big sector and the small triangle, and deducts the calculation method of this SVPWM in details. The advantage of the neutral-point balancing problem of the three-level neutral-point-clamped (NPC) inverter has received a large amount of attention in recent years. This paper mainly analysis the cause of the neutral-point balancing problem of the three-level neutral-point-clamped (NPC) inverter and contrives a new way of balancing the neutral-point voltage by analyzing conventional the neutral-point balancing techniques .At the same time, the new technique has been introduced in the over-modulation area, by this way, the SVPWM of three-level neutral-point-clamped (NPC) inverter can be controlled continuously, the voltage output of three-level inverter has been heightened. This control strategy based on SVPWM of three-level inverters has been simulated by MATLAB, and proved the correction of modulating means.What is more, the control and experimentation interface of three-level inverter has been designed where the TMS320F2407A DSP (TI) is the core, application procedure of this novel control strategy has been compiled. Finally, good result was achieved on three-level model inverter.