NYPA proposes substation work to provide voltage control

 The New York Power Authority (NYPA) is requesting a minor change to the environmental management and construction plan (EM&CP) for the Marcy South 345-kV transmission facilities to install a shunt reactor and associated equipment at the Coopers Corners substation to provide voltage control.

The New York State Public Service Commission (PSC) in January 1985 issued an opinion and order granting a certificate of environmental compatibility and public need for the transmission facilities, which consist of about 207 miles of 345-kV transmission lines, the expansion of six existing substations and the construction of one new substation.

Currently, the transmission system near the Coopers Corners substation, located in Sullivan County, N.Y., and surrounding areas experience low load, high voltage conditions during the off-peak months, NYPA added in its Nov. 14 filing with the PSC.

To alleviate the high voltage condition, the New York ISO (NYISO) has periodically ordered NYPA to operate its Blenheim-Gilboa pumped storage power project’s units in “speed-no-load” and “spin-pump” mode, potentially damaging those units, or to perform manual transmission line switching, which is a labor intensive activity, NYPA added.

In the System Impact Study (SIS), NYISO Interconnection Queue #373, it was determined that the installation of a 200 MVAR, 345-kV shunt reactor at the Coopers Corners substation would reduce the high voltage problem, NYPA said, adding that the NYISO Operating Committee has approved the SIS.

According to the company ABB (NYSE:ABB), which focuses on power and automation technologies, a shunt reactor is an absorber of reactive power, thus increasing the system’s energy efficiency, and it is the most compact device commonly used for reactive power compensation in long high-voltage transmission lines and in cable systems.

NYPA said in its filing that it has proposed a 2014 commercial operation date in the NYISO interconnection queue.

NYPA’s current schedule requires about four months for project installation, NYPA said, adding that the ground clearing and foundation work is scheduled to begin in January 2014.

New York State Electric & Gas (NYSEG) owns the Coopers Corners substation, including the land, and there are seven transmission lines – 115-kV and 345-kV – and additional smaller, distribution lines entering and exiting that substation.

NYPA also noted that NYSEG is supportive of the project as its transmission lines coming into and out of the substation experience the same high voltage problems as the NYPA lines. The installation of the shunt reactor will provide voltage control at the substation, as well as other area substations, NYPA added.

The equipment to be installed includes the shunt reactor, disconnect switches, extension of the existing 345-kV bus, extension of the existing ground grid and station service transformer.

NYPA further noted that the existing control building will be expanded and two NYSEG-owned existing 115-kV circuits within the existing substation will be re-routed. Those 115-kV circuits do not have existing Article VII certificates, NYPA said, adding that NYSEG has applied for a building permit to expand the control house.

Among other things, NYPA said that the installation of the shunt reactor meets the minor change criteria set forth in the opinion and order as it will have only a minor environmental impact, mainly during construction, and a review of the hearing record for the opinion and order, as well as the record supporting the EM&CP order approving the EM&CP, shows that the proposed changes to the Coopers Corners substation were not contested during the proceeding.

NYSEG is a subsidiary of Iberdrola USA, which is a subsidiary of Iberdrola S.A.

About Corina Rivera-Linares 2807 Articles
Corina Rivera-Linares, chief editor for TransmissionHub, has covered the U.S. power industry for the past 13 years. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial. She has also covered such topics as health, politics and education for weekly newspapers and national magazines. She can be reached at corinar@pennwell.com.