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Frankfurt (Germany), 6-9 June 2011 Economic assessment of PQ solutions Helge SELJESETH – Norway – RT 2b – Economic assessment of PQ solutions Frankfurt (Germany), 6-9 June 2011 Customer(s) complaint(s) Statistical PQ measurement Evaluation/ verification of complaint(s) (measurements) In compliance with nat.reg.(or int. std.) NO YES No action required NO May PQ mitigation/solutions be economic? YES Selecting the best eco./tech. compromise Frankfurt (Germany), 6-9 June 2011 Examples of PQ solutions Network reinforcements Thicker lines/cables Larger transformer Increased system voltage etc Voltage booster STATCOM Synchronized switches Petersen coils/Arc suppression coils Local production (may be both at problem and a solution) Grounding Surge arrestors Protection circuits and adjusting/tuning protection circuits Passive filters/Active filters Maintenance level Uninterruptible power supplies – UPS Soft starters and frequency converters Emergency generators ETC… Frankfurt (Germany), 6-9 June 2011 Considerations selecting PQ solution: Technical reasons Economic reasons (Environmental / Esthetic reasons) Frankfurt (Germany), 6-9 June 2011 Relative consequences of voltage disturbances for different customer categories in Norway (1993 – 2010) Infrastructure Large customers Industry (without ”Large customers”) Study on Estimation of Costs due to Electricity Interruptions and Voltage Disturbances Governmental services (without ”Infrastructure”) Households Commercial services (without ”Infrastructure”) REPORT for: Council of European Energy Regulators (CEER) Frequency of the supply voltage Low Medium Low High High Medium Supply voltage variations Medium Medium/high Medium/high Medium/high Medium/high Medium/high Voltage dip Medium Medium Medium Medium/high Medium/high Medium/high Voltage swells Medium/high Medium/high Medium/high Medium/high Medium/high Medium/high Rapid voltage change Low/medium Low/medium Low/medium Low/medium Low/medium Low Flicker Medium Medium Medium Medium Medium Low/medium Transient over-voltages High High High High High High Unbalance Low/medium Medium Medium Medium/high Medium/high Low/medium Harmonic voltage Medium Medium Medium Medium/high Medium/high Medium Interharmonic voltage Low Low Low Low/medium Low/medium Low Frankfurt (Germany), 6-9 June 2011 Results from customer surveys give a better foundation for optimisation of power quality Planning of power systems (expansions...) Operation and maintenance Guaranteed PQ levels, contracts, softened N-1 criterion etc. Monitoring PQ Cost-benefit of PQ improving measures, priorities for load shedding, contingency planning, preventive maintenance etc Policies, standards and criteria for PQ Basis for concession applications, justifications of investmens etc Actual levels vs standards, expectations etc PQ regulation (taking explicitly account of PQ costs) Incentive based regulation, penalty schemes etc. Frankfurt (Germany), 6-9 June 2011 Economic assessment of PQ solutions Frankfurt (Germany), 6-9 June 2011 Total costs VS customer costs (net costs) Total socio-economic costs of quality problems in electricity supply Non-monetary Net costs to rest of society - Direct - Indirect Monetary - Direct - Indirect Non-monetary Total socio-economic costs - Direct - Indirect Private customer costs (net costs) Monetary - Direct - Indirect Frankfurt (Germany), 6-9 June 2011 Real life experiences Some times quite easy decision Easy to see what is the economic solution Some times very difficult to make a decision purely on economic evaluation Difficult to specify the costs for low PQ (flicker, RVC) Frankfurt (Germany), 6-9 June 2011 Location 1 Location 2 Year (1) (2) (3) (1) (2) (3) 1990 91 40 5 94 35 4 1991 145 39 8 100 60 1 1992 106 84 4 101 27 5 1993 49 0 1 61 22 3 1994 75 0 5 61 15 2 1995 110 0 4 59 20 3 1996 203 0 7 100 245 1 1997 113 0 8 124 0 1 1998 156 1 0 110 0 0 1999 114 0 5 33 1 2 1 Temporary earth faults – self extinguishing faults. Temporary earth faults causing short interruption – auto reclosure. 3 Sustained earth faults. 4 Peterson coil in operation in location 1 from medio August 1992. 5 Peterson coil in operation in location 2 from ultimo August 1996. 2 Petersen coil 10 (Arc suppression coil) Frankfurt (Germany), 6-9 June 2011 Voltage booster Increase the voltage at the far end of distribution lines An alternative to distribution network reinforcements http://www.magtech.no/ Frankfurt (Germany), 6-9 June 2011 Frankfurt (Germany), 6-9 June 2011 Frankfurt (Germany), 6-9 June 2011 GAS treatment and export plant 2-side supply (ring) Interruptions do not often occur The plant trips several times per year due to network related events - mainly voltage dips. The events causing trip are mainly supplied through only one of the supplying lines -> single sided supply would have reduced the number of plant trip to less than half The reason for the events are to a significant extent the network configuration The most economic solution would be to supply the plant from one side only if only the available power was high enough Frankfurt (Germany), 6-9 June 2011 2 cases of flicker from harmonic voltages What is the cost of flicker? How bad must the conditions be before mitigation must be performed? In both these cases the limit value value for Plt of EN50160 and both Pst and Plt of the Norwegian PO regulations were not exceeded. Frankfurt (Germany), 6-9 June 2011 THANK YOU FOR YOUR ATTENTION!