Basics of HVDC: AC compared to DC Dr. Ram Adapa Technical Executive, EPRI
[email protected] HVDC Lines and Cables Course June 12, 2017 © 2017 Electric Power Research Institute, Inc. All rights reserved. Increased Benefits of Long Distance Transmission .Carrying energy from cheap generation sources which are far away from the load centers. .Long distance transmission increases competition in new wholesale electricity markets . Long distance electricity trade could include across nations or multiple areas within a nation and allows arbitrage of price differences .Long distance transmission allows interconnection of networks and thus reducing the reserve margins across all networks. .More stable long distance transmission is needed to meet contractual obligations 2 © 2017 Electric Power Research Institute, Inc. All rights reserved. Transmitting Fuel versus Transmitting Energy .Load centers can be served by: – Long distance transmission with remote generation – Transmitting fuel to the local generation facilities .Bottom line is Economics to see which option is better .Depends on many factors – Type of fuel – coal can be transported, hydro can’t – Cost of transporting fuel to local generators – Availability of generation facilities close to load centers – Allowable pollution levels at the local gen. facilities 3 © 2017 Electric Power Research Institute, Inc. All rights reserved. Long Distance Transmission – AC versus DC .AC versus DC debate goes back to beginnings of Electricity – DC was first (Thomas Edison) – AC came later (Tesla / Westinghouse) .AC became popular due to transformers and other AC equipment .Long Distance Transmission – AC versus DC - based on economics and technical requirements 4 © 2017 Electric Power Research Institute, Inc. All rights reserved. 5 5 © 2017 Electric Power Research Institute, Inc.