Analysis of partial discharge and lightning impulse strength properties of nano silica modified corn oil for high voltage insulation applications

Abstract

Increasing Demand For Electricity Has Led To The Design Of High Power Density Transformers With Superior Insulation. Transformer Industries Concentrate More On Improving The Dielectric Properties Of Liquid Insulation, Since 75% Of The Transformer Failures Are Due To Insulation Problems. Recent Technological Advancements Have Shown Path To The Development Of Natural Ester Based Transformer Oils Considering Its Advantages Over Conventional Mineral Oil. Many Research Works Have Shown That The Dielectric Properties, Thermal Properties And Partial Discharge Characteristics Of Natural Ester Oils Are Better Than Conventional Mineral Oil. Corn Oil Is Also Considered As A Suitable Alternate Candidate For Mineral Oil And Results Are Shown In Many Earlier Works. Recent Technological Advancements In Nanotechnology Made It Possible To Develop Nanofluids For Transformer Insulation Applications. Nanofluids Prepared With Mineral Oil As A Base Fluid Shows Enhanced Dielectric Properties. In Similar Line, Researchers Are Also Developing Nanofluids With Vegetable Oils As A Base Fluid And It Is The Hot Research Topic Nowadays. In Order To Qualify Nano Modified Natural Ester Insulating Fluids For Transformer Applications And Also To Have A Common Dielectric Clearance Design, It Should Have Similar Partial Discharge (Pd), Lightning Impulse (Li) And Power Frequency Breakdown Voltage (Bdv) Characteristics Comparable With Mineral Oil. It Is Important To Understand The Polarity Effect Of Lightning Impulse Waveform As Per Iec Standard At Different Electrode Geometry Such As Needle/Plane And Needle/Sphere. It Is Also Vital To Evaluate The Pd Inception Characteristics Of Nano Modified Oils With Respect To Presence Of Void In Pressboard, Presence Of Metal Particles And Bubbles And At Different Electrode Geometry. Collection Of Such Data Will Be Useful For Electrical Utilities To Develop Efficient Condition Monitoring Systems For Prevention Of Insulation Failure And Breakdown Of Expensive Equipment. In Addition, The Influence Of Concentra