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Daedalus was the mythical great architect and artificer of the classical world. Today, embedded intelligence is enabling the most profound changes in the way we create and use buildings since his day.

Building Intelligence meets the Intelligent Building. The Intelligent Building negotiates with the Intelligent Grid. How will this transform how we interact with the physical world?

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« Architecture in the Mist | ESIF and Security at the Edge of Smart Grids »
Sunday
Jun102018

Laminar Control and Transactive Energy

Laminar control is drawing a lot of attention from utilities today, and it may just clear the way be the basis for distributed transactive energy (TE).

The problem of smart grids boils down to adapting to intermittent power sources while reducing the operating margin. In power distribution, the operating margin is the amount of “extra” power available at any time. It is the operating margin that protects power delivery from unanticipated power consumption. This causes a volatility of power supply even while it reduces the ability of the traditional grid to adapt to consumers.

The intermittent power sources are distributed, meaning that they cannot supply any consumer not within the local distribution line unless that power travels between lines. For some users, these power sources will be local, and using them locally may not require permission from the grid. Some smart microgrids will not even be attached to the larger grid, so the model cannot rely on central control.

The power utilities have made heroic efforts to try to build a central control system that can manage this growing complexity and volatility with less margin for error. They still have little ability to provide an optimum solution to the knowledge problem of diverse technologies serving diverse purposes to support diverse activities. We are now seeing the beginning of a top-down re-architecting of the grid. 

Laminar Control manes an approach that layers the operation of power distribution. A lamina names a discrete adjacent layer, a term usually used for tissues in biology or for layers in rocks across a geological area. Laminar Control delegates decision-making to the Laminar Control Nodes within each lamina. Upper layers provide guidance based on strategic surveillance and offer situation awareness. Laminar Control nodes respond as best they can and provide telemetry up. Each node may itself have lamina underneath, with its own control nodes. At the lowest level, decision-making may use mechanisms such as traditional demand response (DR). This model pushes decision-making pushed down to the lowest layer, also referred to as the Edge. The Edge is where the local situation can be more clearly perceived and rapidly acted on. Even if there are disruptions in communications or power supplies from above, the elements at the edge can continue in semi-autonomy to complete the mission at hand.

Bottom-up re-architecting of the grid is getting to the same place. A FSGIM-aware facility is a facility ready to act as a Laminar Control Node. A FSGIM-aware node is also ready to negotiate with its peer nodes even in the absence of the higher lamina. A vehicle, then, acts as a mobile control node. Whether it is a peer node to the building systems, or it is a member of a lamina below the building or facility is an implementation decision.

Some early adopters of this edge-based decision-making are those interested in cybersecurity for their systems. For some, it is not enough to hide the internal mechanisms of their power generation and power management, but they want power cloaking as well. They have no interest in sharing any information of the internal workings of their FSGIM-aware facilities. They view the inside of a facility as a discrete security realm. The growing expectations are that a microgrid should cloak power signatures as well as controls. Clearly this model is not accepting of third party monitoring, let alone third party control.

Circling back to the electric vehicle, as a simple cartoon of these issues…

As a mobile control node it needs to understand, about itself, in information model conformant with FSGIM, or the CTS at least. As the EV drives around, it parks within different microgrids, which may opt to not share any information about this control node with the others. We can also imagine a charging station connected directly to the substation, allowing the car to act as a peer control node to the distribution microgrids.

Throughout, this car should be a car as any other. The V2B interactions and the V2G interactions should be the same. In either case, it should be laminar control node, acting autonomously with other nodes, to achieve directives from the lamina above….

The purpose of the Facility Smart Grid Information Model (FSGIM) (ASHRAE/NEMA/ANSI 201) is to prepare building-based systems to talk to the grid. Traditionally, such systems ignored power supply and demand, and simply assume it was there for them. It does not dictate what such a system does with that information. If could be merely to share its upcoming plans with its supplier, or it could negotiate changes to those plans.

The important part is the power *effects* of the activity, and not the details of the activity. There is far too much diversity in building systems and the business activities they support to expose direct control. One of the Regulated Environment facilities that Jim Butler’s company is known for could incur huge losses in dollars, and possible large health and safety risks by simply accepting a HVAC “nudge” from a far-away system operator.

This is exactly the information that an electric vehicle should have about itself. It should internally know those things that FSGIM describes, and use that information to share its upcoming plans with its supplier, or it could negotiate changes to those plans. That negotiation is properly with the facility it is plugged into, and we should not assume that is “the grid.” A car may be in an urban parking lot during the day a home at night, and at charging in an off-grid wilderness retreat on the weekend.

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