Multilevel inverters for motor drives and wireless power transfer applications

This paper focuses on the incorporation of multilevel inverters in motor drives and wireless power transfer (WPT) applications. The proposed topologies of multilevel inverters are analyzed along with their benefits in corresponding applications. In motor drive systems, the Neutral Point Clamped (NPC) or Diode Clamped topologies with Sinusoidal Pulse Width Modulation (SPWM) as well as Space Vector Pulse Width Modulation (SVPWM) techniques are considered to reduce the harmonic distortion of the output voltage. In addition, in WPT systems the Cascaded H-Bridge inverter (CHB) is considered and analytically described as means to reduce the dv/dt stresses on power switches and also to increase the total power level by exploiting independent generation units. A capacitance detuning method is introduced to achieve Zero Voltage Switching (ZVS) conditions and thus minimization of switching losses. Simulation and experimental results demonstrate the feasibility of the proposed schemes.