© ABB Group August 7, 2015 | Slide 1 Variable Shunt Reactors Optimize Transmission Systems Dr. Claes Bengtsson, Global Product Manager, Reactors. PowerGen Europe June 2010

© ABB Group August 7, 2015 | Slide 2 Matured products ??  Is transformer- and shunt reactor technology matured?  Some basics around reactive power compensation  New opportunities in reactive power compensation  Applications and benefits

© ABB Group August 7, 2015 | Slide 3 P 2, Q 2 U2U2 U1U1 Q Voltage profile at no or low load (P 2 ),”Ferranti effect” U1U1 U2U2 1,0 pu Voltage at line end increases at low load

© ABB Group August 7, 2015 | Slide 4 P 2, Q 2 U2U2 U1U1 Q Voltage profile at no or low load (P 2 ), with connected SR U1U1 U2U2 1,0 pu The shunt reactor stabilize the system voltage The shunt reactor consumes reactive power generated by the transmission line

© ABB Group August 7, 2015 | Slide 5 P 2, Q 2 U2U2 U1U1 Q Voltage profile at no or low load (P 2 ), with connected SR U1U1 U2U2 1,0 pu The shunt reactor stabilize the system voltage Switching in the reactor gives a step change in the voltage on the transmission line

© ABB Group August 7, 2015 | Slide 6 P 2, Q 2 U2U2 U1U1 (R) + X Q Increased load (P 2 ), voltage profile with connected SR U1U1 U2U2 1,0 pu The voltage profile is load dependent

© ABB Group August 7, 2015 | Slide 7 Fundamental challenge  The is an optimum reactor rating at a certain load  Load varies with time  Seasonal variations  Daily variations  Shunt Reactors are by tradition fixed in rating  Switching fixed reactors in and out leads to  Voltage steps  Wear on breakers  Non-optimal compensation

© ABB Group August 7, 2015 | Slide 8 ABB is the world leader on HV shunt reactors  >1000 reactors delivered to >40 countries  Complete range  <800 kV, <300 Mvar  Full 3-phase testing capabilities  Outstanding performance  Field reliability  Low sound and vibrations  Leading the technology development  World’s largest 3-phase reactors (300 Mvar)  So why selling static reactors when the need of reactive power compensation is dynamic?

© ABB Group August 7, 2015 | Slide 9 There are new solutions today  A new product class: Variable Shunt Reactors  VSR provides dynamic compensation of reactive power  Regulation range around 100% (e.g Mvar)  Ratings up to 200 Mvar, 500 kV  ABB is the world leader for VSRs  So far 16 VSRs sold to US, Norway, Denmark, Sweden and Africa  The world’s largest VSR now in safe operation  Mvar, 400 kV

© ABB Group August 7, 2015 | Slide 10 VSR applications: Wind parks  Unpredictable and fluctuating active power exchange  The variations in reactive power consumption with varying wind-power production require control:  SVC  Regulated shunt reactor  Switched shunt reactor  Grid codes specify the amount of reactive power exchanged with the main grid

© ABB Group August 7, 2015 | Slide 11 VSR applications: Large and long cable networks  Large and long AC cable networks in EHV network systems, e.g. USA and Italy.  Extended use of cables put higher demand on reactive power compensation  Daily and season load variation in highly populated areas  Power quality is important

© ABB Group August 7, 2015 | Slide 12 VSR applications: Daily load variations in regular networks  Transmission systems with time variation of load, generation and power exchange with other networks  Interaction with other types of installations, e.g. SVCs, HVDC transmission links  Controllability of the system increase in importance or is uncertain  Increased demands on flexibility  Power quality is important

© ABB Group August 7, 2015 | Slide 13 Summary of VSR benefits  Reduced voltage jumps during switching operation  Voltage stability at varying loads  Flexibility for new future load conditions  Improved interaction with other equipment  Coarse tuning of SVC equipment for best dynamical operation  Reactive power compensation related to loading of HVDC links (a HVDC converter consumes reactive power)  No parallel fixed reactors, reduction of number of breakers, reduced footprint and maintenance  Flexible spare unit possibility and flexibility to move a VSR to other location

© ABB Group August 7, 2015 | Slide 14 Conclusions  Transmission networks have time varying loads  Transmission networks have time varying needs for compensation of reactive power  VSR is a new product type that provides this  Do we know the load- and generation patterns of tomorrow?  A shunt reactor with fixed rating have a life time of 30+ years...

© ABB Group August 7, 2015 | Slide 15 Gallery Mvar, 242 kV Dominion, USA Mvar, 400 kV Statnett, Norway Active part Mvar, 242 kV

© ABB Group August 7, 2015 | Slide 17 Why to be careful when buying a reactor?  It should withstand the load of 40 cars, applied 100 times per second for 30 years continuous without rattling and high noise  Long time field reliability is a key issue  Shunt reactors are difficult