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Delta Person CC Project

VIEWS: 4 PAGES: 6

									    Delta-Person Generation
       Expansion Project

  (OASIS #IA-PNM-2007-02)

Interconnection Facilities Study


           Final Report
            April 2008


            Prepared by:
Public Service Company of New Mexico




                            Electric Services
                       Transmission Operations
                                     Foreword
This report was prepared for PNM Resource Planning and Technical Analysis by the
Transmission Operations Department at the Public Service Company of New Mexico
(“PNM”). Any correspondence concerning this document, including technical and
commercial questions should be referred to:

                                  Gregory C. Miller
                       Lead Director of Transmission Operations
                       Public Service Company of New Mexico
                              Alvarado Square MS-0604
                               Albuquerque, NM 87158
                               Phone: (505) 241-4570
                                Fax: (505) 241-4363




IA-PNM-2007-02 Facilities Study Report   Delta-Person Generation Expansion Project   i
1. Introduction
On March 2, 2007, PNM Resource Planning and Technical Analysis Department
(“Interconnection Customer”) perfected a request to interconnect an A10 steam turbine with 95
MW net output (“Project”) to the Public Service Company of New Mexico’s (“PNM”)
transmission system. This Project would operate as a combined cycle plant with the existing
Delta Person combustion turbine. The Project’s proposed in-service date is March 2010.
Consistent with previous interconnection studies, it was assumed that the Project would be
interconnected at the existing Delta-Person unit 115 kV tie line, as shown in Figure 1.

                West Mesa                                                         KAFB
                 115 kV                        46 kV                             115 kV
                                               System



                         Person 115 kV
                                                                                   Existing Delta-

                                               SP 115 kV
                                                                           ~       Person CT

                                              Line (radial)
                                                                   ~
                      Tome                                    Proposed Project
                     115 kV                                    (ST Addition)

                            Figure 1: One-Line Diagram with Proposed Project

In response to the above request, PNM Transmission Operations (“PNM”) conducted a Facilities
Study (“Study”) to provide cost and construction schedule estimates for the required
transmission upgrades identified in the corresponding System Impact Study 1 (“SIS”). The SIS
identified the following Facilities Study Components:

      a. Address the Person – Prosperity – KAFB 115 kV (PS) line overload. Power flow
         studies showed that this overload is caused by the Sandia 345/115 kV transformer
         contingency. The SIS indicated that PNM planned to increase the rating of the PS line to
         240 MVA by December 2011, and that the Project’s in-service date could be met if the
         planned PS line upgrade project were accelerated.

      b. Address possible impact to breakers at West Mesa and Person 115 kV stations. A
         preliminary short circuit analysis indicated that the interconnection of the Project could
         impact breakers at West Mesa 115 kV and Person 115 kV switching stations. If system
         reinforcements are required as a result of the interconnection of the Project, PNM
         indicated that a series reactor could be installed on the bus tie connecting the West Mesa
         1 and West Mesa 2 switching stations.

1
    Delta Person Expansion Interconnection System Impact Study, Final Report, August 2007.


IA-PNM-2007-02 Facilities Study Report           Delta-Person Generation Expansion Project           1
2. Facilities Study Results
   a. Person – Lomas 115 kV (PS) Line Overload
Upon more detailed analysis, PNM has determined that the PS line overload is a pre-existing
condition. The detailed analyses took into account the fact that the Pajarito/Prosperity system
upgrades, as well as the Lomas – Person 115 kV line, have been delayed beyond the ten year
planning horizon. Taking this into account, and assuming that the existing Valencia, Delta
Person and Reeves generating facilities are at full output, the PS line loading would be 8% above
the existing rating of 156 MVA, as a result of the Sandia 345/115 kV transformer contingency.
With the Project in service, the overload increases to approximately 17%. Reducing Reeves
generation increases the PS line overload. Reducing Delta-Person and Valencia Energy Facility
generation would reduce the overload.

To address this pre-existing condition, PNM plans to upgrade the PS line by Summer 2013 to
achieve a rating of 240 MVA. This rating would be sufficient to prevent overloads with the
Project in service. Until the PS lie is upgraded, PNM plans to address this overload by re-
dispatching load-side generation. The same approach could be used after the Project is
interconnected. However, due to the higher overload magnitudes with the Project in service,
advancing the PS line upgrade may be required, depending on the actual Project in-service date
and other factors. Advancement cost associated with the PS line upgrade, if required, will be
addressed in the Interconnection Agreement.

   b. Short Circuit Duty at West Mesa and Person 115 kV Switching Stations
Based on more detailed analysis, PNM has determined that the present short circuit duty at West
Mesa 1, West Mesa 2, West Mesa 3 and Person 115 kV switching stations exceed the rating of
several breakers. To address this pre-existing condition, PNM proposes to install a series reactor
on the West Mesa 1 – West Mesa 2 bus tie summer 2010. Short circuit analyses indicate that,
with the series reactor installed, the addition of the Project does not exceed the capability of
breakers at West Mesa or Delta Person (see Appendix B).

   c. Interconnection Configuration
The SIS assumed that the Project would interconnect to the existing Person 115 kV station at the
same bay as the existing Delta-Person unit. Therefore, modifications to the existing Person 115
kV station are not required to interconnect the Project. However, a 115kV breaker at the
Customer’s side of the Point of Interconnection would be required to allow for synchronization
of the steam unit (Figure 2).




IA-PNM-2007-02 Facilities Study Report   Delta-Person Generation Expansion Project       2
          Figure 2: Preliminary Proposed Interconnection to the Person 115kV Station




3. Conclusion

The Study determined that the PS line overload identified during the SIS is a pre-existing
condition. The pre-existing overload condition will be addressed by re-dispatching load-side
generation until the PS line is upgraded, and the same approach could be applied after the Project
is interconnected. Due to the higher overload magnitudes with the Project in service, advancing
the PS line upgrade may be required, depending on the actual Project in-service date and other
factors. Advancement cost associated with the PS line upgrade, if required, will be addressed in
the Interconnection Agreement.

The Study also determined that the installation of a series reactor at West Mesa is required to
address a pre-existing need. Assuming that the series reactor is installed, the interconnection of
the Project would not cause additional short-circuit impacts.

Interconnection Customer is required to install a breaker to allow for synchronization of the
proposed steam turbine addition, as shown in Figure 2.




IA-PNM-2007-02 Facilities Study Report    Delta-Person Generation Expansion Project        3
Exhibit A

______________________________________________
From:           Conrad, Stephen
Sent:           Friday, March 07, 2008 3:46 PM
To:             Ellis, Abraham; Mechenbier, Jeff
Cc:             Petersen, Rahn D.
Subject:        Person Generation Expansion - Fault Study

We have studied the proposed expansion of the simple cycle to combined cycle generation at Person to
determine if this project addition will negatively impact Person Station breaker interrupting capacity.
Using the detailed model of the breakers and the ASPEN Breaker module, we find that the Person
expansion will not exceed the existing breakers interrupting capacity.


S.P. Conrad, P.E.
System Protection-System Engineering
Public Service Co of NM
505 241-2672 Ofc
505 241-2363 FAX




IA-PNM-2007-02 Facilities Study Report            Delta-Person Generation Expansion Project    4

								
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