Platt Perspective on Business and Technology

Online social networking and community when machines think – next generation SCADA systems as paradigm for next generation social networks

Posted in business and convergent technologies by Timothy Platt on May 8, 2010

One of the key points I have been developing in this series is that as soon as Web 3.0 and automated processing and use of data streams entered the infrastructure to social networking, that infrastructure entered the conversation in its own right too. I have written about this with a focus on the Turing test and its implications when it is met in Part 1 of this series and I brought in the concept of indeterminacy in Part 2. I mentioned in that posting that Part 3 of this series would focus on SCADA (Supervisory Control And Data Acquisition) systems as a working example and add that I have been thinking about writing a posting on these systems for well over a month now.

The specific type of SCADA system I want to focus on here is that of next generation electrical power grids and I start by outlining in brief summary a little as to how power grids are set up and run.

All electrical power transmission since Edison has run on alternating current. His initial efforts to build electrical power grids were based on direct current transmission, but direct current attenuates and is lost over a much shorter transmission distance than can be achieved with alternating current. One consequence of this is that power grids are more dangerous as it is alternating current that carries real danger of electrocution. Another consequence that is more important here is that alternating current-based grinds have to be maintained in a very particular type of dynamic balance. When a generator produces electrical power it generates a flow of electrons into the network represented as current, and this is propelled by an electromotive force (EMF), or voltage in the direction of that current. But that EMF is balanced by a counter-force called the counter-electromotive force (CEMF) or back-electromotive force that operates in a direction against the flow of current.

This is an important factor in the design and running of any alternating current power system but it becomes particularly important when networks are assembled that include more than just a single power generation source. The collective effect of these forces on geographically wide-ranging grids that include multiple power sources is that EMF and CEMF have to be kept in balance at all times, and as power demand and power levels generated rise and fall and at all points within this system.

SCADA systems are coordination systems and as such are sometimes compared to distributed control systems that more directly control each node. In this example, separate power plants are controlled locally but coordinated regionally to maintain this dynamic balance. And this can become tricky when there are unanticipated spikes in power demand. That can lead to events like rolling brownouts or blackouts when capacity to coordinate effectively in real-time to a rapidly changing flow of demands cannot keep up with shifts in power production and utilization throughout the system. A failure to maintain ongoing real-time systems-wide coordination can lead to rolling massive blackouts and to significant damage to power generators and other network components if one major power source suddenly and catastrophically goes off-line. That is when a significant part of the country suddenly experiences loss of electrical power and this can take significant time to fully recover from, and with ongoing repairs needed that continue way beyond initial restoration of power flow per se.

SCADA systems are often divided conceptually into a set of distinctive core component types and I will briefly outline a few of them here for further discussion. These systems are usually constructed out of a combination of:

1. A supervisory computer system that gathers information from remote sources throughout the system (the automated part of data acquisition) and that sends out commands in response (the automated part of control in these systems.)
2. Remote terminal units and programmable logic controllers that gather data at remote locations through out the system and that carry out the coordinating commands sent back to them.
3. A communication infrastructure connecting more central command and control, and more peripheral data collection and command execution components
4. A human-machine interface where direct human intervention enters in to monitor, manager and if need be over-ride automated processes and responses.
5. A quality assurance oriented events recorder and records-keeping database system for monitoring both individual events and long term trends.

The more data is required at any given time for effective real-time coordination and management of a system and the shorter the time frames that real-time positive control has to be carried out in, the more automated the system has to be to work effectively. So when only relatively small volumes of data need to be analyzed on an ongoing basis and when immediate coordinating response is not needed, there is less pressure to automate. When volumes and complexity of incoming data become overwhelming and ongoing response has to be made on a very rapid response basis, automation may be the only way.

And this is where the various threads of this series come together.

• Power grid networks generate very large volumes of digital, analog and mixed data and the volume of this data increases dramatically as the size and complexity of the network increases, in keeping all components and sub-systems in balance.
• Secure online systems with web interfaces for human oversight and management offers an effective approach for setting up these systems on existing infrastructure.
• The complex of data types, all converted to digital form when not starting out that way, fits very effectively into the capabilities of Web 3.0 database and data analysis systems, and this creates the types of quality assurance and records keeping system mentioned in point 5 above as an automatically included capability.
• These entire systems can be viewed as ongoing multiple-direction communications of data and processed information, and of coordinating commands and feedback.

Reliability is essential for developing that next generation electrical power grid that can more easily absorb potential disruptions, and even from sudden loss of key power generating nodes. This reliability will depend in very large part on data sharing and processing capabilities that can only come from automation and from bringing this increasingly intelligent infrastructure into the conversation.

That is not to say that human monitoring and intervention are not needed as they are still going to be essential. Any event or circumstance that has not been planned into the automated systems and their built-in business rules will require this. But day to day and ongoing operations will require more, and more effective automation – and more active networking participation.

And if the power flows effectively and without interruption and even when demand levels shift dramatically, it will not matter what part of this SCADA system is human-control based and what part is automated and intelligent infrastructure-based. They will both simply be contributing to the same ongoing conversations with effective power generation and distribution the result.

3 Responses

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  1. […] Platt on May 10, 2010 In the third part to this series on intelligent infrastructure networks: Next Generation SCADA Systems as Paradigm for Next Generation Social Networks I presented a case for developing a next generation SCADA (Supervisory Control And Data […]

  2. […] through on this foundational topic. I then turned to examine two specific test cases with a posting on next generation electrical power grids and a posting on financial instruments trading and exchanges. Both of these focused on SCADA […]

  3. […] simply reduce it to the state of a set of connected dumb networks such as we have with our current electrical power grids and our financial instruments trading systems – vulnerable to catastrophic […]

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