Today's post is brought to us by our guest. He is Daryll Valdez, a student from the University of Mindanao, in the Philippines. Darryl is currently finishing his Bachelor's Degree in Electrical Engineering.
A Distribution Automation (DA) System enhances the efficiency and productivity of a utility. It also provides intangible benefits such as improved public image and market advantages. A utility should evaluate the benefits and costs of such a system before committing funds. The expenditure for distribution automation is economical when justified by the deferral of a capacity increase, a decrease in peak power demand, or a reduction in O&M requirements. Distribution Automation Systems have been defined by the Institute of Electrical and Electronic Engineers (IEEE) as systems that enable an electric utility to monitor, coordinate, and operate distribution components in a real-time mode from remote locations.
The DA System is modular and may be implemented in phases to include remote monitoring and control of substation, feeder and consumer devices, and loads. The overall goals of distribution automation are to reduce costs, improve service, reliability, provide better consumer service, and enhance government relations. The successful implementation of the DA System results in deferred capital expenditures, reduced operations and maintenance expenses, improved outage response and restoration, enhanced system efficiencies, enhanced consumer satisfaction, improved data and information, positive public Image.
Fundamentally, there are three components of a system-wide distribution automation system. These include control centre-based control and monitoring systems, including distribution SCADA or distribution management systems; the data communications infrastructure and methodology required to acquire and transmit operating data to and from various network points in addition to substations; and the various distribution automation field equipment, ranging from remote terminal units to intelligent electronic devices required to measure, monitor, control and meter power flow. Taken together, expenditures for this wide range of electric power grid distribution automation activity exceed $1 billion dollars each year.
Distribution Automation functions can provide both benefits and challenges. Often these benefits and the challenges are closely intertwined, with the real and complete benefits not achievable until some of the challenges (including the financial challenges) have been overcome. Yet waiting for these challenges to be overcome or ameliorated often means missing out on some of the benefits – not doing anything can often be worse than doing something. Therefore the key to distribution automation is assessing the balance of benefits versus challenges, including the “lost opportunity” risks of doing nothing.
The distribution automation functions can in general be divided into two main categories, namely customer level functions and system level functions. The customer level functions are those functions which require installation of some device with communication capability at the customers’ premises. These include load control, remote meter reading, time-of-use rates, and remote connect/disconnect the system level functions are those functions which relate to system operations. The control and communications devices for these functions are installed at different locations in the system, such as substations and feeders. These functions include fault detection and service restoration, feeder reconfiguration, voltage/var control etc. In addition to system operation type functions, digital protection of substations and feeders is considered part of distribution automation in some situations.