Retrofit of HT Motor with LT Motor and VFD - An Energy Conservation Technique

摘要

Due to rapid industrialization globally, there is huge shortage of electrical energy, which calls for additions to the existing generating capacities. But the limited availability of natural resources, the immediate solution to the power crisis is “Energy Saving”. Most of the Industries use A.C. Induction motors whose utilization is more than 80% of energy generated globally. Variable Frequency Drives (VFDs) are being incorporated to the existing L.T. Motors (up to 480 Volts rating) which results in greater energy savings. In the present era of Fourth Industrial Revolution, there is a need to save power in H.T. Motor (3.3, 6.6 and 11 KV ratings) segment also. Due to circuit complexity, huge cost and space problems of HT VFDs, it is preferred to retrofit existing HT or HV (High Voltage) Motors (preferably up to 400 kW rating) with L.T. Motors which facilitates easy incorporation of VFDs. This paper deals with the requirements and modifications/alterations required for this type of retrofit work with a case study, taken from one of the continuous process chemical plant and the fruitful results obtained are highlighted.