Research Project Summary Information
Development of Practical Reliability for Electric Power Distribution :Development of Practial Reliablity for Electirc Power Distribution (ST10677-1)
The opinion that reliability and momentary power quality events need to be considered simultaneously is both newly emerging and controversial. The modern electric power distribution system is facing multiple changes - new reliability requirements and incentives, more stringent customer needs that require a higher level of power quality, and advanced technologies that capitalize on new design options. All of these changes mean that the distribution system designer is facing a much wider range of considerations when approaching upgrades to the system. While the distribution system designer is often aware of these changes individually, there is no unified design procedure for incorporating all of these changes into a particular design and evaluating competing options.
The project investigates the resources for providing a distribution system designer with; reliability based performance incentives or penalties, new technologies available related to SmartGrid ties, and selection criteria for most effective system upgrades to meet reliability as related to distributed generation influence to the grid. The design criteria indices used to measure the reliability of the utility will be examined in detail, with suggestive possible improvements. These indices being:
System Average Interruption Frequency Index (SAIFI),
System Average Interruption Duration Index (SAIDI).
Customer Average Interruption Duration Index (CAIDI)
The project utilized a decision-making tool called “Analytical Hierarchy Process” (AHP), which aids in decision making when choosing between several similar alternatives. Testing this tool against multiple fault data sets provided by two (2) NY utilities, provided realistic outcome scenarios for designing to reliability standards. The project enabled the communication among utilities within NY State, culminated by a one day meeting at National Grid (Albany, NY), in which five of the major utilities sent representation from their distribution design departments to view the project results/findings and engage in common dialog. This is a key step in helping utilities discover that they encounter similar issues and circumstances among their profession and can resort to collaboration to solve these very issues. Benefits from others and their experiences will go far in promoting this technique.
Contributions to the following four (4) areas were made from the project findings:
- Development of a formal decision-making tool for evaluating and selecting new equipment
- Advanced analysis of utility fault data to determine fault causes and establish historical fault rate data sets
- Development of consistent design metrics for evaluating competing options based on existing reliability and power quality indices
- Analyzed the relationship between extreme weather and distribution line fault rates
The Contractor used distribution fault data records from two (2) NY Utilities to exercise the AHP decision making process, with evaluated outcomes on the design process. Two (2) new reliability/power quality indices suitable for use in the distribution system design process emerged; Sustained Momentary Average Interruption Frequency (SMAIF) and Average Annual Effective Interruption Time (AvAeT). Case studies were presented for both of these indices that illustrated their use and demonstrated applicability in providing a consistent basis for comparison of design options.
Attn: Comptroller's Office Po Box 5546
Potsdam, NY 13699
NYSERDA Contact Information
R&D -Transport & Power Systems