Smart Meters (Advanced Metering Infrastructure or AMI)
Risk Reduction Category
Technology Description
By 2023 most utilities are using Advanced Metering Infrastructure (AMI), replacing the spinning disk and monthly meter reading with solid state, multi-function, and two-way communicating smart meters. Besides benefits in streamlining the billing process, these meters provide benefits to utilities (and their customers) via increased system awareness. Most meters, regardless of manufacturer provide features such as counters, registers, and flags that can be used by utilities if their head end systems are configured to ingest and process these inputs.
Utilities can configure a smart meter installed at a residence or commercial building to detect momentary interruptions. The voltage threshold and time duration defining a momentary interruption varies according to utility policy and is programmed into the configuration file of the smart meter. After the threshold for a momentary interruption is exceeded, the smart meter increases the count within a local storage register. The cumulative value of the storage register is often referred to as the click count, where the word “click” represents a momentary interruption, and the value of click count corresponds to the number of momentary interruptions experienced by the end user. [1]
The click count from an individual meter is transmitted to a central repository and cleared from the register at some time interval determined by utility policy. Once received by the utility, the click count is time-stamped and placed within a database. Application software is used to analyze the data. With appropriate software, the combination of GIS information and the electric circuit model overlaid with information about momentary interruptions enables utility planners to identify areas for both vegetation management and inspection of conductors and equipment in the suspect area. Subsequent analysis of adjacent customers, data from the SCADA system, and other databases such as the past schedule for vegetation management are used to isolate and identify the source of the momentary interruption. [1] Mapping and analysis of momentary interruption data enable a utility to identify priority areas with a likelihood of future disruption of service and to flag those areas as high-priority candidates for preventive maintenance. [2] All of these benefits indirectly feed into a wildfire prevention strategy. Yet another use case is benchmarking performance of a wildfire mitigation investment before and after installation. For example, a utility may want to measure the fault reducing performance of covered conductor on a test circuit before committing to widespread use. Doing so could include analysis of historical AMI data from all customers on the test circuit compared with data from the same meters after installation of the covered conductor. Depending on the capabilities of the meters, they may include minor faults that are not otherwise captured by substation monitors or relay operations.
Technical Readiness (Commercial Availability)
While the overall system for such a momentary interruption analyzer application is complex, it builds upon the existing AMI investment and infrastructure. Custom queries, which can be considered a form of proprietary software, are needed that reside on top of existing software. In-house expertise is needed to design and perform the queries.
The following are well known manufacturers of AMI systems, each of which claims at least hardware support for detecting voltage sags (indicating that a fault occurred, but not necessarily with an accompanying interruption). These manufacturers make the data available for 3rd party developers to build custom applications.
General Electric
https://www.gegridsolutions.com/products/brochures/kv2-family_gea-12673.pdf
Eaton
Itron
Implementations / Deployments
While AMI is mature technology and widely deployed, specific use cases such as those described here may be provided either by in-house resources as a one-off analysis or by application extension by 3rd party developers who integrate software within an enterprise head-end system.
Innovations as of Mid 2023
Potential Enrichment Work Opportunity
References
[1] Application Readiness Guide Version 2: Assessment of AMI and DSCADA Applications with High Value Volume 2. EPRI, Palo Alto, CA: 2015. 3002007029.
[2] NEMA. “Smart Meters Can Reduce Power Outages and Restoration Time.” National Electrical Manufacturers Association. https://www.nema.org/Storm-Disaster-Recovery/Smart-Grid-Solutions/Pages/Smart-Meters-Can-Reduce-Power-Outages-and-Restoration-Time.aspx.