Exploring Multi Phase Transformer and Floating Voltage Source Inverter Based Induction Motor Drive System

The main technical challenge in the adjustable speed drive system is the harmonic injection by the operation of conventional power converters. These harmonic components are responsible for the violation of utility company standards by the industries, and compensations to this utility companies impose heavy penalty on the industrial users. However, the currents at grid side and drive side are evidently distorted by the large, injected components, while little research has been done to study and solve this problem. Therefore, phase shift technique based multi-pulse converter has gained attention in high-performance adjustable speed drives owing to their myriad advantages. Despite the converters demonstrate the improvements in the power quality performance, instead the utilization of this single technique is not beneficial because it gives acceptable performance with high number of DC source system. This paper introduces an multi pulse converter configuration with the hybrid technique (assignment of phase shift and multi-phase) to stacking large number pulse with few numbers of DC output sources. Hence, the transformer winding connection for 30-pulse AC-DC converter is designed in such a way so that five-phase output voltage is obtained from the secondary windings, whereas the primary windings are powered through the three-phase supply. Apart from this, floating voltage source inverter based four-level multi-level inverter configuration is introduced to attain the excellency in the response at the motor end. Hence, the presented configuration of the power converters is capable to efficient utilization of electricity, which is the main agenda at the global level. The presented configuration effectiveness is examined experimentally on a reduced scale experimental set up (7.5kW,415V, IM), as well as using simulation (2.7MW, 6.6kV, IM) results.