1
TRANSMISSION SYSTEM OVERVIEW TRANSMISSION SYSTEM OVERVIEW NETWORK OPERATING COMMITTEENETWORK OPERATING COMMITTEE
April 17, 2007April 17, 2007
New Mexico Transmission System New Mexico Transmission System OverviewOverview
2
Efficient Use of Existing Efficient Use of Existing Transmission SystemTransmission System
Long-term weather study (8 weather stations) Increased rating (18%) of transmission lines by using less
conservative wind speed assumptions
Real-time monitoring Installed monitoring equipment to allow for temporary
increase of emergency ratings based on actual (as opposed to worst-case) temperature and wind conditions
Traveling Wave Fault Recorders on all 230kV, 345kV line and key 115kV lines
Disturbance Monitors Bulk transformer online monitoring (oil, temperature, hot
spots)
Risk management (Video Sagometers) Several lines exposed to low-probability, short-duration
events have been rated for high-temperature operation
3
Efficient Use of Existing Efficient Use of Existing Transmission SystemTransmission System
4
Efficient Use of Existing Efficient Use of Existing Transmission SystemTransmission System
Reactive Compensation & Voltage Support Series compensation of 345 kV lines Shunt capacitors Albuquerque power factor control (RCCS)
Transmission Line Clearance Over 1500 miles of transmission lines have been phase-
raised to remove ground clearance limitations.
Emergency Procedures Automatic load shedding schemes, as safety net
measures, to handle deficiencies in transmission capability during peak usage during scheduled maintenance and forced repairs
Reactor contingency scheme
5
WECC/NERC CriteriaWECC/NERC Criteria
Planning and Operations CriteriaWECC/NERC Standards
Current System Capability with All Lines in Service (N-0)
All facilities within normal rating limits Voltage levels shall be within normal limits Network stability shall be maintained All customer demands shall be supplied and all firm transfers shall be maintained
Current System Capability with one line out of Service (N-1)
All facilities within emergency ratings No bus voltage drop greater than 5% 5% Real and Reactive Power Margins Transient voltage dip should not exceed 20% for longer than 0.33 sec Transient frequency dip should not exceed 59.6 Hz for longer than 0.1 sec
Current System Capability with two Lines out of Service (N-2)
All Facilities within emergency ratings No bus voltage drop greater than 10% 2.5% Real and Reactive Power Margins Transient voltage dip should not exceed 20% for longer than 0.67 sec Transient frequency dip should not exceed 59.0 Hz for longer than 0.1 sec
6
Generation InterconnectionsGeneration InterconnectionsA Few FactsA Few Facts
Received 50 generation interconnections since 2000 (42 direct interconnect and 8 are joint studies)
Signed 6 LGIA for a total of 768 MW 451 MW Wind 317 MW Gas and Bio Mass
Today’s Queue 5 Feasibility Studies 6 System Impacts Studies 4 Facility Studies
1562 MW Wind 1479 MW Gas and Combined Cycle
7
New Mexico Wind Energy New Mexico Wind Energy CenterCenter
Located in Eastern Located in Eastern New MexicoNew Mexico
204 MW capacity204 MW capacity Supplies up to 20% of Supplies up to 20% of
PNM’s total demand at PNM’s total demand at any given timeany given time
Supplies approximately Supplies approximately 3.5% on the average3.5% on the average
Installed in 2003, in Installed in 2003, in record time!record time!
Owned and operated Owned and operated by FPL Energy by FPL Energy
PNM purchases & PNM purchases & markets all the outputmarkets all the output
8
Technical SpecificationsTechnical Specifications
136 towers, each 210 feet tall Base circumference is > 40 feet! Wind Farm spread out over 15 miles
Three blades at top of each tower, each 110 feet in length
Facility feeds power onto nearby PNM high-voltage transmission line
9
How Wind Turbines Produce EnergyHow Wind Turbines Produce Energy
Blades rotate toward the wind Winds of 6 to 7 mph are enough to turn
blades Blades turn a shaft connected to the
rotor of an electric generator Mechanical components can withstand
winds of up to 55 mph
Person on top of rotor
10
NMWEC Power Output PatternNMWEC Power Output Pattern
PNM Load Pattern (08/03-PNM Load Pattern (08/03-08/04)08/04)
WinterPeak Load
Spring/FallLoad Valleys
Summer Peak Load
11
Questions?Questions?