Power and Process Worlds Melding Thanks to Software

July 24, 2008
Talk about mergers and acquisitions! Once upon a time, the two technological realms of power automation and process automation were totally separate and entirely distinct. However, an elegant combination of Siemens Energy & Automation’s software and related equipment is beginning to bring Power Transmission and Distribution (PTD) functions within the orbit of the company’s familiar PCS 7 process automation software.

This evolution was described in detail by Bill Joss, regional business manager for PTD in Siemens’ Energy Management and Automation division, during his presentation, “Integrated Process and Power Automation,” this week at the 2008 Siemens Automation Summit in Chicago.

“The future is that power and process are merging, but Siemens is the only company that can do it for now because of PCS 7,” said Joss. “We’ve had Totally Integrated Automation (TIA), but now we have Totally Integrated Power (TIP) too.” The company also demonstrated its TIP efforts in a special demonstration in an 18-wheeler parked at Navy Pier.

Joss explained that TIP makes use of the IEC 61850 standard, which basically allows different substations to communicate with each other via Ethernet technology. This allows power data to be sent and displayed on the process automation side.

These operations are carried out by Siemens Control and Monitoring (SICAM) Power Automation System (PAS), which takes information from the data-acquisition level, such as low- and medium-voltage equipment information, and then sends it via an IEC 61850-enabled common bus up to the SCADA and visualization systems, and finally on to the analysis and decision-making level.

SICAM consists of a hardened server―an industrial PC running Power Automation System (PAS) visualized through WinCC and other related equipment. Remote connections can be made via intelligent electrical devices (IEDs) and the Web through the firewall in SICAM’s Diamond servers. SICAM also uses SoftPLC software to develop reusable function blocks to add new capabilities.

“We also support OPC via SIMATIC OPC Link to tie power systems into the process control system,” added Joss. “SICAM really is a bridge to the past and a bridge to the future. SICAM’s Power Automation software bolts onto PCS 7 and doesn’t require any separate hardware or software to seamlessly merge the process and power sides, which no one else is able to do.”

SICAM’s other technical features include:

  • Acquisition and transmission with real-time stamping on the place of origin at 1 millisecond resolution
  • Support of substation control functions and switching authority, bay blocking and telecontrol blocking
  • Fault recording of the protection devices via IEC 60870-5-103, Profibus FMS, IEC 61850 and ILSA protocols
  • Redundancy on the bay, station and HMI levels
  • Local visualization, archiving and logging with SICAM PAS Control Center (CC) and full-graphic visualization based on SIMATIC WinCC
  • Automation functions via CFC and Structured Text.

“The benefits of using SICAM PAS include efficient operation, clearly structured HMI display with SICAM PAS CC based on Windows technology, two-stage switching, security against unauthorized switching, safer working conditions via functions like switching authority and bay and/or station blocking, fast error detection and localization,” added Joss. “It also provides automation functions to optimize plant uptime and increase availability with power shedding, on-board tools for commissioning and testing and operations.”

In addition, IEC 61850 allows SICAM to communicate via Generic Object-Oriented Substation Event (GOOSE) messages. These are based on inter-relay communications, and Joss reported that they can significantly replace wiring by enabling functions such as interlocking, reverse blocking, relay coordination, load shedding and capacitor bank coordination.

For example, the municipal electric utility in Naperville, Ill., recently used SICAM and IEC 61850-enabled GOOSE messaging to communicate between bay-level IEDs. “The utility’s former engineering time for conventional substations was 10 man-days, but by using IEC 61850, that was reduced to three days, for a savings of seven days per substation. Naperville is now deploying its seventh substation using the 61850 architecture for a savings of 42 man-days or about $42,000 in total.”