PREPA goes Mobile – Field Crew Enlightenment

PREPA goes Mobile – Field Crew Enlightenment

José A. López Rivera
Puerto Rico Electric Power Authority
Email: jalopez@prepa.com

Francisco Maria Sarmento Intergraph Public Safety Email: fmsarmen@ingr.com

Abstract
PREPA, Puerto Rico Electric Power Authority, is an electric utility company that faces all normal operational problems and in addition has to deal with major disruptions due to violent hurricanes that wreak havoc on the entire island of Puerto Rico.

Once a hurricane or other natural disaster hits the island, PREPA must prepare estimates of the damaged facilities in the first 24 hours after the disaster. After reports are complete, it is necessary to evaluate the cost to repair the damages, availability of repair crews, and to allocate appropriate money to pay for the damage. These requirements led PREPA to implement the AIRe project (Integrated Resource Management System).

Focusing on the mobile application that distributes the data and tools available in the office to the field crews, this paper addresses the business requirements that led PREPA to define the AIRe architecture, the solution implemented, and the benefits expected and achieved.

PREPA Background Information
PREPA * is an electric utility owned by the government of Puerto Rico. It is responsible for generation, transmission and distribution and is the only electric utility in Puerto Rico.

The following table describes some statistics regarding PREPA’s service territory:

Table 1: PREPA’s Statistics
The central portion of Puerto Rico is very mountainous, with peaks up to 4,390 feet, and many small winding roads. A yearly hurricane season – June through November – is a constant challenge in Puerto Rico. In 1996, Hurricane Hortense cost PREPA $22 million in electric facility repairs. In 1998, Hurricane Georges, the worst hurricane in recent history, caused $226 million in damages to PREPA’s electric network with a loss of electrical services lasting from days to months throughout the island.

PREPA’s transmission and distribution responsibilities are divided into seven regions containing twenty-seven districts. PREPA has 450 two or three man crews to construct, operate and maintain all transmission, and distribution assets.

Since 1999, PREPA has been implementing the AIRe project, which integrates several corporate systems, including Work Management, Customer Information, AM/FM/GIS, Financial, Human Resources, Electrical Analysis, SCADA, and Outage Management. Integration of these systems to seamlessly provide information to management, engineering, administration, and field crews to support accurate assessment, smart decisions and rapid deployment is the objective of the AIRe system.

Field Work
PREPA’s fieldwork can be organized as three major activities, as represented in the following diagram:

Figure 1: PREPA’s most common activities performed in the field.
Each one of these groups has different characteristics, however, some functions may overlap.

Normal Operations. Includes scheduled work, such as, construction, capital improvements, meter installation, planned switching, tree trimming, pole inspections, etc.
Emergency Operations. Includes “routine” non-scheduled work dealing primarily with customer outages.
Natural Disaster Operations. When a hurricane or natural disaster hits and damages large portion of the electrical network, crews of all types, including office personnel, retired personnel, and sometimes crews from other utilities, are pressed into emergency services to restore service as quickly as possible. The number of field personnel may be increased by 20 to 30 percent when allocating these resources to the fieldwork.

All crews are managed at a district level. Some of the construction crews may be managed at a regional level. For Normal Operations, prior to AIRe, crews received daily assignments at their offices early in the morning from District Engineers. A District Engineer is responsible to manually maintaining the Daily Report, which tracks each individual on the crew, his work performed, his time spent in the field, etc. The AIRe systems are now handling many of the tasks that were formally performed manually by the District Engineers and their staff.

Figure 2: PREPA has 7 Regions, 27 Districts, and 430 crews to work under Normal and Emergency Operations. The available crews can grow during Natural Disaster Operations.
Natural Disaster Operations
Although AIRe is being implemented to support all three major fieldwork activities, this paper will focus on natural disaster operations. The work performed after a hurricane is almost the same as that performed under normal and emergency operations – the major difference is the amount of work and stress imposed on PREPA employees.

Hurricane Georges
On September 20-22, 1998 Hurricane Georges crossed Puerto Rico. By September 24 the entire commonwealth of Puerto Rico was declared a disaster area requiring emergency and permanent public assistance for all categories. The Federal Emergency Management Agency (FEMA) provided assistance to relieve cash flow problems experienced by PREPA, due to the high expenses incurred during that period.

Table 2: Hurricane Georges (The values are expressed in Millions)
During the first five days of the storm, PREPA did not deliver energy to customers. Although the generation and transmission systems did not suffer major damages, the distribution system was badly affected, causing major revenue losses from non-delivered energy. To repair the network, PREPA had to utilize crews from other utility companies, transport transmission structures to rural areas by helicopter, provide ice to some critical customers, hire local contractors, build temporary roads to access assets in rural areas, in addition to other extraordinary activities. On the administrative side, one of PREPA’s major challenges was to ensure that all the work related to network restoration was properly accounted for in order to justify the costs to FEMA. The second major challenge was to prove to FEMA what facilities existed in the ground before the hurricane. Without accurate and reliable information that could be validated by FEMA inspectors, FEMA would not reimburse PREPA for the repair costs.

Pre-hurricane work
Prior to the hurricane hitting the island, PREPA has only a couple of days to prepare. There is not much fieldwork to be done during this period but, administratively, PREPA prepares for the hurricane according to its existing Emergency Plan. This plan is elaborated by district and considers the need to create Temporary Operation Centers, critical customers who need to be restored quickly, materials to stock upfront, people to alert, and the creation of appropriate charge accounts, among other preparatory activities. District Engineers are responsible for the execution of the Emergency Plan within each district.

Post-hurricane work
During the first 24 hours after the hurricane, PREPA must provide to the commonwealth governor and all affected municipalities, a damage estimate and the number of disconnected customers. This estimate is high level and based on information gained from:

Helicopter assessment along the transmission lines to detect damages;
Tripped breakers identified by the SCADA system;
Tripped breakers identified by field crews after visits to all substations;
Customer outage calls.

At the same time, crews start repairing the network according to the Emergency Plan – initially they restore critical customers. As the emergency repair progresses, other crews inspect by walking the entire network. As information is collected, permanent repair work is designed and implemented. The permanent repair work, in some cases, undoes the emergency repair work that restored critical customers.

Mitigation / Preventive work
Part of the post-hurricane work, is the mitigation work. During this phase, the damage is analyzed and PREPA designs and implements changes to the network to minimize the future impact of a hurricane.

So, how can taking the information to the field improve the natural disaster work?
As mentioned before there are two major tasks to be performed by the field crews: emergency repair work and detailed inspection of the damage. These crews need to have similar information to perform their tasks – electrical network data. Repair crews need to know how the network looked before so they can restore it as close as possible to the original. The inspection crews need to know where the network was supposed to be in order to understand and identify where the damage occurred.

Giving access to this information to crews in the field will speed the work and reduce the amount of radio communication needed for clarification and decisions between field crews and district engineers – note that the radio infrastructure may have been damaged as well, leaving the crew almost isolated in the field. The first requirement is for the crew to be able to locate itself on the digital map (with the use of a GPS coordinate or by locating a landmark, street address, street intersection, etc. on the map) and display the network that used to exist on that location (with all tabular information required, such as wire size, transformer size, fuse information, pole height and class, etc.).

Figure 3: The field crews can locate the working location on the map and review network information as it existed before the hurricane. Complementing the graphic information, field crews access the non-graphic network information.
Having this information available in the field is only half the benefit. The other half is being able to enter information from the field and use it back in the office. For instance, this data might consist of the changes made to the network (i.e., it may be that a specific wooden pole is no longer available and the repair crew had to install a concrete pole). Inspection data is also collected in the field and integrated with the AM/FM/GIS data:

Figure 4: Inspection crews can enter detailed inspection information on the feature while in the field and use it later in the office to prepare reports and to plan the permanent repair work.
Entering information in the field reduces errors and ensures that all required data is captured, avoiding subsequent trips to the field to complement information collected on a piece of paper. In order to take full advantage of the ability to add and edit the information in the field, it is necessary to be able to incorporate it into the corporate database in the office without re-renter the data. Once the information is integrated into the corporate database, reports can be easily extracted, permanent repairs can be designed, and the information necessary to design the mitigation work will be available to engineers.

Figure 5: A corporate database serves data and is updated from several different systems. PREPA expects to reduce the number of days and amount of administrative work that is necessary to produce the FEMA reports, which took 154 calendar days (including field inspection) for Hurricane Georges.
Implementation Strategy
PREPA is currently undergoing the huge task of field inventory and data conversion. Even though not all network data is available, PREPA is currently using the mobile units for:

Field Inventory and Data Conversion QC
Design network modifications
Routine Pole Inspection
Capture of new construction As-Builts
Data Maintenance

These are basically the same tasks that will be performed under the Natural Disaster conditions, however, without the volume or stress typically encountered during storms.

The flexibility of this implementation is such that AIRe provides for the use of paper maps in situations where crews do not have access to field computers or have not yet been trained on the new technology. In these cases, collected field information will be entered into the corporate database from the paper maps.