A novel concept of secondary substation monitoring: Possibilities and challenges

Smart Grid concept substantially increases the measurement need in the future for efficient and flexible power delivery. Distribution network monitoring has been traditionally focused on primary substation (i.e., high voltage/medium voltage), whereas least attention has been given to secondary substation (i.e., medium voltage/low voltage). Distribution network operators are facing considerable network investments in the near future due to the renewal of aging cable networks in cities and renewal or replacement of overhead lines by underground cables in rural areas. To focus on the network renewals at the correct places to decrease the occurrence and duration of unplanned power interruptions and to maintain good power quality despite the proliferation of e.g. distributed generation and electronic loads, the need for proactive network monitoring is ever increasing. Secondary substation is an ideal location for data acquisition because both MV and LV network can be monitored. This paper proposes a novel cost-effective secondary substation monitoring concept for smart grids which can be installed permanently at secondary substation for partial discharge (PD) monitoring, power quality (PQ) monitoring and disturbance recording. No sensors having expensive high voltage insulations are needed, which makes the solution cost-effective and reliable.