Development of an input power factor corrected variable speed motor drive system for the electric motor drives course

An active input power factor correction (IPFC) is introduced as a front-end converter for the variable speed induction motor drive (IMD) system. This paper provides the involvement of the system power quality which involves a high power factor (PF) and low total harmonic distortion (THD). The necessity for efficient utilization of generated electrical energy is growing in order to optimize the usage of utility power plant capacity. Moreover, awareness of minimizing harmonic contamination in the electric power line is rising due to the increased use of electronic equipment powered by an ac-to-dc bridge rectifier with large filter capacitors and/or a switchmode power supply (SMPS). The variable speed motor drive (VSMD) saves more electrical energy than the fixed motor drive under the assumption that both are operating on the same load factor. Almost all of the small VSMDs have no IPFC circuits to save their production costs. Emerging applications of fractional horsepower IMDs - such as compressors, appliances, blowers, hand tools, and heating, ventilating, and air-conditioning (HVAC) - invoke the urgency of studying the effects of the IPFC on the VSMDs. A three-phase inverter-fed IMD with a single-phase source and an active IPFC circuit is proposed in this paper to study the impact of IPFC circuit experimentally. The foremost subject in the study of an input PF corrected VSMD are the effects of an IPFC circuit on overall system efficiency and input PF. Empirical comparisons between the conventional bridge rectifier circuit and IPFC circuit in terms of PF and efficiency against motor speed are developed. The overall system performance with an IPFC circuit is better than the system performance without it in terms of harmonic contents and PF. The system efficiency, however, shows marginal inferiority with an IPFC circuit because the front-end IPFC circuit and the three-phase inverter are connected serially. It should be emphasized that the IMD with IPFC is desirable in utilizing the generated electrical energy effectively and minimizing the harmonic contamination. The developed system may be useful as a hands-on experiment for the Electric Drives course. In conclusion, various teaching components are defined with the developed IPFC-IMD system.