Make better use of Real-Time Energy Information to improve service reliability
Outage Management
The following discussions explore how OMS can analyze the data acquired by AMR and put it to
use to improve the customer response and service restoration processes. While few utilities have
actually implemented the outage monitoring functions of AMR, many are considering them
(Brown, 2000). AMR is not a substitute for OMS, and vice versa. AMR provides valuable input
to OMS with automated outage notifications and confirmations of service restoration. OMS
supports the management of restoration resources (crews and materials needed and where they
are needed), customer communication (why the lights are out, and more important, when the
lights will be back on), emergency switching design, and reliability analysis and reporting.
Outage Notification
AMR can let the utility know if services have been interrupted before customers call. Of
particular importance is that the utility is notified without the customer being on the premises.
Practical considerations in implementing the outage notification function include the latency and
reliability in the transmission of the real-time data and the filtering of momentary service
interruptions.
Data Latency — Depending on the number of customer interruptions and the bandwidth of the
data network, there may be a delay of as much as thirty minutes between the time when a meter
detects a service interruption and the time when the utility operation and dispatch center receives
the notification. Still, the meter data will most likely help the utility diagnose outage locations
faster and more accurately because many customers will not call the utility to report an outage
within the thirty-minute window. Moreover, most utility customers would see the automated
outage notification as a value-added service — it protects them from spoiled food in the freezer,
for example, even when they are not on the premises when the outage occurs.
Reliability of Data Transmission — Common AMR meters do not include batteries, so outage
notification relies on the last gasp signal sent by the meter when loss of power is detected. Due to
the nature of wireless communications, the signal sometimes may not reach the utility operation
and dispatch center. With the advanced trouble analysis methods in OMS products today, the
percentage of customer interruption messages that actually get through is generally adequate to
determine the possible outage locations in the distribution network accurately. On the other hand,
the lack of data transmission robustness means that the utility will still need to rely on customer
calls to determine secondary service outages to some extent.
Momentary Interruptions — To reduce the data network traffic and the workload of outage
dispatchers, the utility may want to filter momentary from sustained interruptions by letting the
AMR system or the AMR/OMS interface wait one to five minutes to determine whether the
service is restored before sending the interruption event to OMS. (The IEEE guideline for
defining sustained outages is five minutes.)
Outage Confirmation
When processing a customer trouble call, before logging the trouble call, the utility should first
confirm whether the customer premises is part of a known outage in OMS and if not, query
AMR to check if the premises has service, in that order.
Checking with the OMS database — When a customer calls to report an outage, he or she
mostly wants to know if the utility knows about the outage and when service will be restored.
This information is contained in an OMS. OMS not only has possible outages estimated based on
other calls and AMR notifications, but also confirmed outages based on operational events from
SCADA, the estimated time of restoration and current work status from field crews, etc.
Querying the AMR server — If the customer premises is not part of a known or possible outage
already determined by OMS, in cases of the customer call coming before AMR notification due
to data latency or data communication problems on the AMR network, the utility should
combine the call information with other customer calls or AMR outage notifications already
received to help determine the more likely outage location. To confirm if the outage is on the
distribution system before dispatching a trouble investigator to the premises, the utility should
check the AMR system to determine if the meter is still energized during the customer call. If
AMR shows a good likelihood of an energized meter, the call agent should then follow a script to
direct the customer to check the house circuit breaker before sending the trouble call to OMS.
Workflow Recommendation — The author recommends that the trouble call entry process
query OMS before querying AMR because (1) OMS contains more information and (2) OMS
typically provides faster response than AMR. In fact, when call volume is high, the utility may
want to skip AMR verification to speed up the call entry process because it is more likely that the
call is already part of a known outage. In the extreme case of very high call volumes during
major system events or storms, the utility may want to skip both OMS and AMR verifications as
part of the overflow call entry process.
