Load shedding

Softeco contributes to the implementation of the control system of the National Transmission Network, providing Terna SpA skills and products for the development and evolutionary maintenance of the SCADA/EMS control system, the Electric Transport Network Defense System, the Wide Area Measurement system, the UPDM remote control devices.

As part of the Italian Electric Transport Network Defense System, the load shedding service allows Terna SpA to reserve an amount of interruptible power (in the 2011-13 period  have been put out for bids 3.800MW shares), that can be used to fast reserve recovery and real time balancing, reducing the risk of blackout events. Softeco has been engaged in the implementation and evolutionary maintenance of the central system management of Load Shedding and Electricity Network Defence system since its conception.

The basic functions that enable and ensure the safety of the RTN are:

  • Centralized analysis of the Power Grid state and countermeasures planning (control actions that shall be issued to load shedding users or generation groups).
  • Continuous and real-time monitoring of the Electricity Network critical sections and broadcast communication of potentially dangerous events.
  • Implementation of load shedding actions (disconnection of loads) or production shedding actions (production reduction by remote disconnection of generation units).

The Central SCADA System, a Linux based architecture, consists of two servers nodes in master/slave hot standby. This architecture allows to have a central system with fully redundant capabilities and man-machine interface. The system has been designed, built and tested to acquire data from 2000 RTUs, corresponding to a minimum set of SCADA objects of 40000 remote signals, 30000 remote commands  and 10000 remote measurements, for a total “up to speed” of at least 80000 SCADA objects, with A3 class availability (greater than 99.95%). The project has been developed according to a quality certified project management model based on a waterfall process template system derived from the ESA standard.

The basic requirement is the time between the the potentially dangerous event onset and corrective action implementation. This is determined through offline studies under static and dynamic conditions and depends from the whole network characteristics and specific critical sections. This parameter is between 100ms and 300ms.

Softeco also provides support and solutions to energy managers of the companies involved in the load shedding service, following them around the path that starts with the feasibility study technical analysis, continues with the interaction towards Terna SpA management offices in charge of issuing the bids and is completed with new users activations.