POWER DELIVERY AUTOMATION

ATCO Electric Studies the Feasibility of Distribution automation

Distribution Automation (DA) is a set of technologies that enables an electric utility to remotely monitor, coordinate and operate distribution components in a real-time mode from remote locations.

General Strategy
The corporate objective of ATCO Electric is to balance long-term distribution costs with reliability and availability. How will DA contribute in maintaining or improving the reliability indices of the distribution system?

What are some of the business issues seen today:

• Operational flexibility has to increase. (i.e. do more with less field and support staff).
• Industry migration to performance based rates.
• Coordination of operational requirements with Independent Power Producers.
• Need more comprehensive outage data.
• Improve system operations by utilizing all monitoring, visibility and control systems.
• Centralizing the function of the Distribution Operator in charge to a centralized location.

Increase Worker Productivity
There is a need to strive for higher manpower efficiency in today's world. We are expected to do more with less. Although DA may not reduce the total manpower requirement, our goal should be to better utilize the existing work force.

• Efficiency is gained by remote control of some down stream feeder devices. Even though this results in manpower and cost savings it will not be enough to pay back the Rate of Return of DA.
• DA will reduce the manpower required to do field monitoring for engineering.
• DA will allow more monitoring and control of the distribution system which will make it easier to maintain acceptable levels of service.
• DA will change the level of technical expertise required in field operations as there will be a greater requirement for electrical and communication technicians.

• DA will reduce outage duration and allow better use of existing equipment.
• DA will also improve the ability for engineers to gather and analyze the data.
• An additional benefit is the ability to do distribution load curtailment on a more precise scale. This could be based on a frequency loadshed or could be peak shaving.

The financial impact of outages on customers is a concern. Some recent studies have quantified customer losses due to outages at about $10 per kWh not served. This cost may not be "hard" enough to dominate an internal business case, however customers will use such reliability numbers when selecting their energy supplier. As the preferred supplier it is important to retain existing loads and franchises.

Reduce Electrical Losses
Due to the inductive nature of long rural lines, there is a significant opportunity to reduce electric losses and improve the poor power factor of much of the connected loads with centralized VAR Dispatch. Voltage control on feeders will also be improved. Reducing electrical losses makes good business sense and it is recommended that a program be commenced with or without DA functionality. There are a variety of concerns and questions as to the economical benefits of reducing the electrical losses.

• How do we gather enough load and voltage data to have adequate design criteria?
• Are the details in our models close enough to the physical layout of the feeder?
• What are the variables under which the compensation has to react?
• How do we validate the actual savings in terms of demand, energy and reductions in the revenue requirement?
• How do we find the long-term resources to make sure the compensation continually performs and to recognize when it has to be adjusted or removed?
• What is the impact to capacitors and harmonics?

Reduce/Defer/Eliminate Capital Investment
The cost of adding DA can be very substantial depending on what, when and how it is implemented. Low cost can be achieved by using existing equipment and minimizing installation requirements. Once DA is implemented there should be a combined reduction in the Operation and Maintenance costs. DA can also lower the amount of capital improvements, which will have a positive effect on revenue requirements.

• The largest single cost of DA is adding SCADA and control of the distribution system at each appropriate substation. Normally, this has been a Transmission Substation cost.
• Adding DA to equipment on the distribution feeders will vary with desired operational benefits. This could range from $2,000.00 to $10,000.00. If equipment is not DA ready there could be an additional retrofit cost to upgrade.
• The use of a submaster device will keep communication costs reasonable if there are multiple controllers and remote terminal units in an area serving a number of automated substation functions.
• DA will provide improved monitoring so line performances will be maximized prior to costly upgrade solutions. Future upgrades will benefit from this experience, as results will be clarified by real time data.

• All new line switching devices installed on the critical sections of feeders will be capable of remote control or at least be easily adaptable.
• ATCO Electric will attempt to utilize as many standard systems as possible so that interfacing and integrating becomes much more practical. New systems and existing programs must be compatible in order for data and results to be shared.
• Communications protocol DNP 3.0 will become the ATCO Electric Standard and be included in all new equipment.

• ATCO Electric will continue to work towards the implementation of Distribution Automation justified on a project by project basis.
• Initiate some short term and long term steady state monitoring of voltage and amperage.
• Standardize operating practices and philosophies around sectionalizing and coordination of service restoration.
• Continue to improve on how we report and manage outage data.
• Develop and apply an application philosophy for drive-by fault indicators.
• Distribution Automation will not reduce outage frequency so the root cause of outages should be managed first.
• The Automatic Meter Reading system used by ATCO Electric is not a viable option as a Distribution Automation communications carrier.
• Continue to look at system improvements to improve system reliability prior to Distribution Automation.
• ATCO Electric will continue to proceed or accelerate the installation of SCADA for distribution breakers in all substations.