Transformer Technology Seminar GIC Capability of Power Transformers

Transcription

1 Pomona CA, May 24-25, 2016 Transformer Technology Seminar GIC Capability of Power Transformers Siemens AG Transformers siemens.com/answers

2 Geo-magnetic Induced Current GIC resistant Transformers page 2

3 Why highlight Geomagnetic Induced Currents Geomagnetic induced currents (GIC s) are caused by recurrent solar magnetic disturbances Significant GIC events 1859 solar super-storm ( Carrington Event ) 1989 collapse caused in Quebec SIEMENS provides specially adapted design and test measures to respond to GIC events Committees and publications on GIC NERC, CIGRE Latest data about GIC presented at the CIGRE colloquium in Zürich, 2013 Contribution in the IEEE WG PC on Thermal response of transformers to GIC Page 3

4 Current practice and development GIC effects on the power grid Transmission lines and transformers are linked to geomagnetic field changes Moderate GIC levels are able to last for several days Adverse impacts to the transformer Page 4 Increased loss of life due to higher hotspots and gassing Worst case Black out of the power grid Affects on transformer performance GICs affect many areas of a transformer s performance Increased temperatures Higher noise levels Additional tank vibrations Higher Reactive power consumption Regarding GIC cases, our know-how is unique due to knowledge gained from extended test series during FAT (back-to-back tests with DC injection). Measures against critical heating Usage of non-magnetic steel GIC safe transformers Extra DC capability, up to 200 Amps

5 Clamping plates Tank Tie bars nearby core Cross section of transformer (upper half) GIC effects on transformers Critical eddy loss heating in metallic parts Tie bars nearby the core are most vulnerable Additional noise increase and tank vibrations Five-limb and single-phase cores are more sensitive Increased currents in the windings Backlash effects from transformer to grid High magnetization current Higher current harmonics Increased reactive power consumption Can cause voltage instability of the total network Page 5

6 Detailed thermo-hydraulic simulation models Simulate critical transformer components Simulate transient hotspot behavior during solar storms Detailed electromagnetic simulation models Different types of models Simulate hotspot behavior during solar storms Nonlinear FEM3D and magnetic network models Eddy loss computation in metallic parts Simulation of back effects on the grid Magnetization currents with harmonics Reactive power consumption Page 6

7 Reference list of GIC studies Customer Limbs PhasesMVA kv Long time emergency condition Short time emergency condition US //345 +/ Amps/phase US Single phase core // 115 // Amps/phase 200 Amps/phase for max. 8 min US //141.5// Amps/phase US //141//23 50 Amps/phase 200 Amps/phase for max. 13 min Reference list of GIC tested transformers Customer Limbs Phases MVA kv Long time emergency condition Short time emergency condition US //345 +/ Amps/phase US Single phase core // 115 // Amps/phase 200 Amps/phase for max. 8 min CA Single phase core // Amps/phase Factory test Page 7

8 GIC Hot Spots Around The World Page 8

9 We can offer: Detailed studies of the transformer behavior during a solar storm can be performed on request Special test arrangements in laboratories can be used to verify the GIC strength of power transformers GIC risk evaluation with only a few transformer design parameters can be performed Page 9

10 Siemens AG - Transformers Contact Martin Stössl Head Global Technology Centre E T TR LPT GTC Elingasse Weiz Austria Phone: +43 (51707) Mobile: +43 (664) martin.stoessl@siemens.com Siemens.com/transformers Page 10