Smart-grid technologies are a key element of upgrades being undertaken by the New York Power Authority (NYPA) at its high-voltage transmission facilities, including those in Northern, Western and Central New York.
The new technologies are consistent with the priorities of Governor Cuomo’s Reforming the Energy Vision initiative to make the state’s electric power system more customer-oriented, versatile and robust. Heightened “situational awareness” of transmission line conditions from the smart-grid design features is a key facet. This will also contribute to enhanced control of power flow and increased ability to deliver additional amounts of clean surplus electricity from upstate power sources to the downstate region.
Among the smart-grid projects that NYPA is pursuing are the following:
Substation Automation Modernization and Controls (SAMAC): NYPA’s St. Lawrence-Franklin D. Roosevelt Power Project is the site for one of the most advanced transmission interconnection systems in North America that will put the hydroelectric facility in the vanguard of smart-grid technology use.
The significance of the SAMAC improvements lays with the enhanced perception of conditions at the plant’s Robert Moses switchyard and on interconnected high-voltage 115-kV and 230-kV transmission lines and substations. The system, which is being installed in a recently constructed electrical-relay building at the switchyard, is designed to instantaneously detect fast-changing conditions before they potentially deteriorate and become a reliability issue.
Begun in the spring of 2014, the smart-grid measures at the Moses switchyard will continue over the next few years. Although ongoing, the SAMAC upgrades are already providing enhanced awareness of transmission conditions.
Marcy-South Series Compensation Project (MSSCP): The MSSC project will help relieve transmission congestion from Central New York to the Catskills without having to build new power lines.
The $54-million project, which is being undertaken by NYPA and New York State Electric and Gas Corp., will increase power flows by up to 440 MWs, making possible the cost-effective transmittal of additional amounts of clean surplus upstate power along two existing 345-kV transmission lines.
A centerpiece of the MSSC project will be three capacitor banks that will make possible greater control and coordination of voltage in support of increased electricity transmission to the downstate region. The capacitors—each about 30 feet wide, 60 feet long and two stories high—utilize smart-grid technology to measure electrical current flowing through transmission lines, with data instantaneously conveyed via fiber optics to a computer-based protection system.
It is expected that the MSSC project will be in service by June 2016.
Dynamic Line Ratings (DLR): DLR technology, consisting of advanced field instrumentation and software, helps track transmission capacity of power lines, as influenced by local weather conditions, such as ambient temperature, wind speed, solar radiation, and humidity. Such real-time information, relayed to a central computer, can be used to dynamically adjust the conductor thermal capacity, resulting in a potential five-to-15 percent increase beyond the rated capacity of a particular line.
This “hidden capacity” can be used to optimize power flows across the grid, contributing to lowering energy costs and greater transmission efficiency without compromising power-line reliability.
Particularly in regions where increased wind generation and other renewable energy sources are limited by transmission constraints, DLR technology, when applied on a wider scale, could have a significant impact on the performance of the state’s transmission lines and their ability to integrate additional amounts of wind power.
NYPA is applying dynamic ratings technologies along three major transmission corridors near its large hydroelectric plants: the 345-kV Niagara-Rochester line, in the area near the Niagara Power Project; the 345-kV Gilboa-Fraser line, in the area near the Blenheim-Gilboa Pumped Storage Power Project; and the 230-kV Moses-Willis-Plattsburgh line, in an area near the St. Lawrence project.
Phasor Measurement Units (PMUs): Another key smart-grid tool for enhanced operation and control of the power grid are phasor measurement units (PMUs) that utilize GPS-synchronized information on power-grid voltages and currents for assessing conditions at specific transmission locations.
NYPA is operating 15 PMU systems at locations that include its Marcy Substation, near Utica, the Niagara project, and the Blenheim-Gilboa project. Installation of new units is also ongoing at various locations like St. Lawrence project and the Authority’s Richard M. Flynn Power Plant, on Long Island.