Networked Energy Management

Recent developments with the ODVA Energy Initiative are focused on a new power management object, which will enable better management of devices and subsystems to save on energy usage during non-operational periods.

Combined with initial work-targeting tools for energy awareness, the latest additions are fundamental first steps in enabling energy management using the Common Industrial Protocol (CIP) and Ethernet/IP. Now, the development challenge shifts to more of a comprehensive view of energy management, and closing control loops to potentially enable a greater level of energy optimization in plants.

By adding new objects and services to the Common Industrial Protocol, the overall strategy with this initiative is to use the power of industrial networking and Ethernet/IP to drive new levels of energy awareness and data sharing. Ultimately, the goal is to take industrial energy management to new levels of granularity, and potentially offer important information to the smart grid as those standards continue to evolve.

The ODVA Energy Initiative started with the release of the white paper in 2011, "Optimization of Energy Usage," which defined three use case types. Use Case 1 is to develop awareness of energy usage. Use Case 2 has been split into two phases, one being the recently developed power management object to send devices to a low power state during non-operational periods, and a second upcoming phase that will enable active power management during operational states. Use Case 3 is a targeted, future development that will focus on optimizing and "transacting energy" through the energy supply chain.

"Phase 2a is the power management object, which provides a standardized way for applications to request that devices go into a low power state during non-operational periods," Rich Morgan, leader of the Special Interest Group and an applications engineer for Rockwell Automation, told Design News. "These time periods might include lunch breaks, a maintenance shift, or the weekend. The object provides a standardized interface for applications to manage devices by putting them, for example, in a reduced power state or sleep mode."

Morgan said he went into the process of looking at power management a little bit skeptical of the value of putting a controller into a sleep state. His vision of most industrial applications was that the control equipment consumes a fraction of the total power of the process. But what they found with a demonstration conveyor system is that going from a fully operational state to a turned off state where everything is stopped -- but all of the controls are energized -- saved about 50 percent of the peak power.

"But if you actually put the controller to sleep by turning off the 24V power supply and waiting for a Wake on LAN signal, it can be reduced down to 15 percent of the overall power being consumed," Morgan told us.

Phase 2b is still in the conceptual stage until the next step in power management can be determined. One of the issues the group is looking at is an extension of the power management object to include control and reduction of power during machine or process states

Add new comment

By submitting this form, you accept the Mollom privacy policy.