Research of Wavelet Modulation for Single-Phase Three-Level Inverter

The single-phase three-level voltage source inverter based on wavelet modulation (WM) is proposed. The WM technique is based on constructing a nondyadic-type multi-resolution analysis (MRA), which supports sampling continuous-time sinusoidal signals in a nonuniform recurrent manner, and then reconstructing it by using inverter switching actions. In order to further improve the output voltage waveform and reduce harmonic distortion, the wavelet modulation is used to three-level inverter. The high magnitude of fundamental component and significantly reduced harmonic contents of the inverter output voltage can be achieved by using WM in the single-phase three-level voltage source inverter. Furthermore, the WM algorithm is implemented by using only one element government (EV) in DSP. The simulated and experimental results prove the accuracy and feasibility of the WM scheme for single-phase three-level voltage source inverter.