A novel three phase infinite level inverter (TILI) topology for induction motor drive application

Abstract

A novel structure of Three Phase Infinite Level Inverter (TILI) topology has been derived from elementary Single Phase ILI (SILI). The rudiment structure of this topology is a DC-to-DC Buck converter followed by a H-Bridge. Fully rectified SPWM (FrSPWM) technique is used as control logic for implementing sinusoidally varying duty ratio delta (d). The proposed topology is compared with traditional inverter topologies and it is proved that the new topology requires minimum amount of DC bus voltage (i.e. for generating 415V RMS value of fundamental line voltage, DC Bus voltage required is only 339V). Only three high-frequency switches are required to realize TILI. To validate the system capability of DC Bus utilization, SVPWM technique has been implemented by hardware in TILI topology (here for generating 415V RMS value of fundamental line voltage, DC Bus voltage required is only 293V). The performance of newly introduced TILI topology has been validated with different load conditions such as resistive load, Three Phase Induction Motor (TPIM) load and the compatibility of TILI is verified for above applications through hardware implementation and analysis. To verify the driving capability of the TILI, speed control experiments were conducted by V/f method and implemented through hardware and its dynamic performance of operations were validated.