Transformer Technology Seminar HV Collector (Power) Transformers

Transcription

1 Pomona, CA, May 24 & 25, 2016 Transformer Technology Seminar HV Collector (Power) Transformers siemens.com/answers

2 Substation for Wind Park Switch Yard HIS, Transformer & MV / Aux Building Page Page 2 09/2015 LiDT - JXN Keith Armstrong/ E T TR JXN

3 Restricted Siemens Energy 2013 All rights reserved.

4 High-level design steps for a windfarm 1. Select site: Wind resource, land availability, transmission availability 2. Select turbine placement on site Wind resource, constructability considerations 3. Select point of interconnection (POI)/collector sub Sites may be remote from nearest transmission Use collector sub, collector voltage to POI (transmission sub): low investment, high losses Use transmission sub as collector station: high investment, low losses Decision is NPV {investment cost + cost of losses} 4. Design collector system Turbine placement, POI/collector sub location, terrain, reliability, landowner requirements Decision is NPV {investment cost + cost of losses} 4 Page 4 09/2015 LiDT - JXN Keith Armstrong/ E T TR JXN

5 Topologies Usually radial feeder configuration with turbines connected in daisy-chain style Usually underground cables but can be overhead è UG is often chosen because it is out of the way from construction activities (crane travel), and ultimately of landowner activities (e.g., farming). A feeder string may have branch strings 5 Page 5 09/2015 LiDT - JXN Keith Armstrong/ E T TR JXN

6 Topologies The five 34.5 kv feeder systems range in length from a few hundred feet to several miles. 6 Page Source: 6 J. Feltes, 09/2015B. Fernandes, P. Keung, Case Studies LiDT - JXN of Wind Park Modeling, Proc. of Keith 2011 Armstrong/ IEEE PES E T General TR JXN

7 Collector System Design Page 7 09/2015 LiDT - JXN Keith Armstrong/ E T TR JXN

8 Minimum information needed Special Requirements Special operating conditions (e.g. restricted air flow, harmonics, etc.) Site conditions: ambient temperature or altitude in excess of ANSI/IEEE? seismic requirements? Overload (per ANSI/IEEE standards?) or excess/company reqm nts? Overexcitation specific overvoltage or underfrequency duty? Physical installation limitations, matching existing pad or unit, etc. System short-circuit capacities (ka or MVA) Step-up Operation only? Or step-up/step-down operation? Restricted Siemens Energy 2013 All rights reserved.

9 Grid Access for Massive Wind Park UG Cabling (MV + HV) & Grid Connection via AC or DC MV / HV Switchgear FACTS & HVDC Cabling MV / HV Grid Connection Page Page 9 09/2015 LiDT - JXN Keith Armstrong/ E T TR JXN

10 Collector System Design Page 10 09/2015 LiDT - JXN Keith Armstrong/ E T TR JXN

11 Collector System Design Page 11 09/2015 LiDT - JXN Keith Armstrong/ E T TR JXN

12 Minimum information needed Transformer Type (two-wdg, autotransformer, GSU) MVA for each winding, for each cooling stage Cooling type (OA/FOA, ONAN/ONAF/ONAF, ODAF, etc.) Temperature rise (65 C, 55/65 C, or other) Winding connections (grounded wye-delta? Wye-wye?) Taps required? Type (de-energized or on-load) Transformer Impedances Loss evaluation -$/kw for no-load loss, $/kw for load loss Location of jobsite (to check shipping limitations) Restricted Siemens Energy 2013 All rights reserved.

13 rating C , Table 10 GSU: Step-up operation, delta primary (generator), wye secondary HV BIL kv %IX LV = 480V %IX LV > 2400V 200 kv (35kV) 7.25% 7.0% 250 kv (69 kv) 7.75% 7.5% 350 kv (69/115kV) % 450 kv (115/138kV) % 550 kv (115/138kV) % 650 kv (138/161kV) % 750 kv (161/230kV) % Restricted Siemens Energy 2013 All rights reserved.

14 Minimum information needed Special Requirements Restricted Siemens Energy 2013 All rights reserved.

15 Collector transformers requirements. Collector transformer connections mostly are specified Y- or Y-Y. Harmonics & grounding system > Play a big role in collector system design Resonance impedance characteristics Background harmonic considerations. Operation of collector transtformers > cyclical nature Some users size their transformers based on loading guide C57.91 Site ambient temperature considerations critical for collector spec Want to go greener? Safer? What about esters? What about synthetic esters? Have you considered voltage regulation on the turbine? Restricted Siemens Energy 2013 All rights reserved.

16 Siemens US Transformers Contact James McIver Principal Application Engineer E T TR US 6860 Bermuda Road, STE 100 Las Vegas NV USA Mobile: (702) james.mciver@siemens.com siemens.com/transformers Page 16 Restricted Siemens Energy 2013 All rights reserved.