Electricity + Control May 2018

CYBER SECURITY

Harmonised PLC Use Through Single Interface Increases Plant Performance

Dirk Mottmann, IS and Process Manager at Umeå Energi.

Dirk Mottmann, IS and Process Manager at Umeå Energi

Umeå Energi integrates Siemens PLCs with ABB Ability System 800xA across its district heat- ing plants to lower operator risk while minimising running and maintenance costs.

A n improved and simplified single operator interface, that gives greater insights into the performance of district heating plants, is re- alised by Umeå Energi after it standardised on ABB control technology. With fewer process screens leading to lower operator risk, the company has sig- nificantly improved monitoring and process control and operator effectiveness of its plants. Because the district heating network had ex- panded over time, the Swedish energy provider found itself using a mix of control systems, Hu- man-Machine-Interfaces (HMIs) and Programma- ble Logic Controllers (PLCs). This was the result of different departments working with various subcontractors employing their own automation solutions for the PLC control. There was no stand- ardisation. Umeå Energi’s ambition is for all its PLCs to be visible through the same HMI, so that the operator would have a familiar work environment, while min- imising risk, operating and maintenance costs. Hav- ing all information available in one single HMI gives the operators and maintenance staff new ways to proactively monitor processes more efficiently and maintain a high system and plant availability. At the heart of its distributed control system are three independent ABB Ability System 800xA platforms, each managing sections of the two dis- trict heating plants covering Umeå. In addition, the company uses 21 Siemens S7-300 PLCs to control

pumps in booster stations and sectioning cham- bers so that the correct pressure is maintained throughout the network. The PLCs were operated using two Siemens Simatic HMIs. However, these HMIs were outdated, making PLC operation increasingly difficult. This led to higher maintenance costs and increased risk. Fur- thermore, with only basic integration with the Abil- ity System 800xA, operators were forced to use different HMIs, each with its own look and feel, to manage different parts of the same plant. While modernising the Siemens HMIs would be the most obvious answer, it would not provide the single operator experience Umeå Energi de- sired. An alternative approach was sought that would integrate the 21 PLCs into ABB System 800xA, which would then act as the main HMI. The fast track way of integrating PLCs is to use ABB OPC Connect; a tool that connects PLC objects and its signals simultaneously, such that up to 50% of engineering time can be saved. This avoids the time-consuming manual integration of individual signals from each asset. Umeå Energi took the opportunity to standard- ise on the function blocks used within its PLCs, thereby removing the many different object types created for the same asset, such as pumps or valves. “We did a thorough work in standardising our function block library. I think it is absolutely necessary if you are planning to do this kind of

Take Note!

Umeå Energi has one common HMI that spans the entire system and its processes. This gives the operator a completely integrated plant and district heat- ing network experience. Furthermore, all pro- duction and distribution network process data are available in one common database.

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22 Electricity + Control

MAY 2018