Transcript Helge Seljeseth

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
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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...)
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Operation and maintenance
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Guaranteed PQ levels, contracts, softened N-1 criterion etc.
Monitoring PQ

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Cost-benefit of PQ improving measures, priorities for load shedding,
contingency planning, preventive maintenance etc
Policies, standards and criteria for PQ

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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
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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
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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!