Optimized Zero Vector Selection in Space Vector Pulse Density Modulation Schemes for Two-Level Inverter Fed Induction Motor Drive

Abstract

Space Vector Pulse Density Modulation (SVPDM) schemes for adjustable speed drives are digital modulation scheme with less computational overhead. The SVPDM based drives provide better spectral features and reduced acoustic noise in motor than Space Vector Pulse Width Modulation (SVPWM) drives. The discontinuous nature of SVPDM scheme is investigated in this article to find optimized zero vector selection in SVPDM schemes for adjustable speed control of induction motor. Five types of Discontinuous SVPDM (DSVPDM) schemes for two-level inverter are proposed in this paper based on selection of zero vectors. Analysis is carried out to find the optimized zero vector selection. Performances of the proposed DSVPDM schemes are compared with existing SVPDM and popular space vector based Discontinuous Pulse Width Modulation schemes. The DSVPDM schemes are validated for a 11.5 kVA two-level inverter driving a 3-HP three-phase induction motor using dSpace DS1104 real time interface platform.

Keywords

• induction motor
• inverter
• sigma delta modulator
• total harmonic distortion
• vector quantization