Transient Performance and Operational Insights of Hybrid 380 kV AC Transmission Systems

Many hybrid Extra High Voltage (EHV) AC transmission systems comprising of a combination of overhead line and underground cable sections are already in operation in Germany with others being in planning or construction phase. Transmission systems are inherently complex structures, involving apart from overhead transmission lines and cables a multitude of additional components, such as cable transition stations with or without shunt reactors for reactive power compensation to ensure stable and efficient operation. Each transmission system is uniquely designed and optimized to meet specific operational requirements and to minimize system losses, resulting in distinct operational characteristics to manage reactive power and maintain voltage stability.