Electrical energy system, its supervising and control.

Previous sections have described the processing in heavy industri, especially in pulp-and paper industri.

Electrical energy demand within those industries require electrical power about 60 MW for one big papermachine.
This is about 500 GWh in a process operating time of 8400 houres a year.

The total industrial elecrical energy demand in Sweden year 2002 was about 50 - 55 TWh of the total demand of 150 TWh.

Such demands need to be supplied from the Swedich main line net in 380 or 130 KV.
The transmission level is reduced to 10 KV and then down to the operating voltage of  500 / 380 V.

The system consisting of transformers and distributed system to the processes should be supervised to ensure that sufficient power is available when needed and with the highest availability.

A monitoring control system for the electrical energy system will indicate and report disturbances, interruptions, and the need for fast repairs in the internal electrical system.
Disturbances from external main line net shall be analyzed and repaired in cooperation with responsible for the internal system.

It is necessary to control the switches and steps switching on transformers in high voltage systems and follow-up the power and the need of electrical energy instantaneously and continuously in the processes as well as information from all electrical units condition as well in level as in function.

KWh = Kilowatt-hours = 1000 Wh
MWh = Megawatt-hours = 1000 KWh
GWh = Gigawatt-hours = 1000 MWh
TWH = Terawatt-hours = 1000 GWh