Transient Analysis for Hybrid Electric Field in close proximity HVAC-HVDC operation of Northeast – Agra HVDC project

Close Proximity Operation of HVAC and HVDC transmission line is the recent trend for increase of power transmission capacity. Need for same is becoming vital day by day due to ever increasing power demand. Erection of HVAC lines has a requirement of high right of way (ROW) as compared to the HVDC lines. Also recent past has witnessed constraint in availability of ROW for many projects of Indian Power Grid. Raise in transmission voltage level of HVDC from Power Grid Corporation of India Limited (PGCIL) and its suitability to decentralized non-conventional grids has led to addition of many upcoming HVDC projects with the already existing ones. So the need of analysis for electric field distribution under this type of hybrid transmission corridor is necessary to meet the standards of engineering design, exposure limits to living beings and environmental protection. The present work shows a two dimensional modelling approach for estimation of hybrid electric field at ground surface with impulse excitation. A practical case of hybrid transmission corridor so formed in Northeast Agra HVDC project of PGCIL has been taken for this case. Effects of both standard and non-standard impulse waveform has been modelled and analysis of its effect on hybrid electric field is presented.