Decision Support Software
for Power System Planning
& Operations
By
Peter Roche, Consultant
CAREC
May 2011
1
Presenter’s Background

Analytical Engineer for HVDC Links

Power System Planning Engineer in Power Utility

Manager of Technical Computer Services in Utility

Consultant in Power System Operations &
Automation
– Responsible for Designing, Specifying & Supervising the
development of SCADA and Energy Management
Systems in over 20 utilities world-wide
CAREC
May 2011
2
Decision Consequences
Value
Generation
Developments
Transmission
Developments
Real-Time
Dispatch
Energy
Market
Time Scale
CAREC
May 2011
3
Generation Capacity Planning
Search for ‘Least Cost Investment Plan’, within

Load growth projections

Energy Constraints – hydro / hydrocarbon availability

Environmental constraints

Fuel diversity objectives

Regional interconnection plans
CAREC
May 2011
4
Load in Gw
Daily Demand Curve
Time of Day
CAREC
May 2011
5
Supply Side
Demand Side
Generator 3
• Econometric
model
• System demand
projection
• Load Duration
Curve
• Energy Growth
rate
• Discount rate
Repeated
Modelling of
Dispatch
No
Transmission
Evaluation
based on
LOLE or
VOLL
•Dates in
Generator
2 & out
•Capacity
•Dates
Generator
1in & out
•Fuel type
•Capacity
•Dates
in & out
•Construction
Cost
•Fuel
type
•Capacity
•OperatingCost
Cost
•Construction
•Fuel type
•Maintenance
•Operating
Cost
•Construction
Cost
Schedule
•Maintenance
•Operating
Cost Value
•Scrap
Schedule
•Maintenance
•Scrap Value
Schedule
•Scrap Value
CAREC
May 2011
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Criteria for Selecting Plan
 LOLE
/ LOLP Loss of Load
expectation
– N instances per annum
 VOLL
– Value of Lost Load
– Depends on state of economic
development
– Depends on estimated value of 1 MWhr
non-supplied
CAREC
May 2011
7
Output from Generation Plan
Subject to various stated constraints
Costed
plan over, say, 30 years
List of instances that exceed stated
acceptance criteria
Based
on user chosen schedule of
proposed generating plant with
– Years in and out of service
– Specified ratings
– Plant utilisation
CAREC
May 2011
8
WASP
Wien Automatic System Planning Package
(WASP) - now in V4
 Model for Analysis of Energy Demand
(MAED) helps in predicting demand
 Originally from TVA……. now available via
IAEA
 Very extensive & detailed models of
generation, demand, external factors

CAREC
May 2011
9
WASP offers
Various thermal plant types
 Various hydro plant & pumped storage
types
 Extensive parameters on plant costs
 Operational & availability plant parameters
 Emission constraints (e.g. GHG)
 Discount rates
 Energy constraints


Extensive Front-end & Back-end support
CAREC
May 2011
10
Other Generation Expansion
Software Models
 EGEAS
from EPRI (Electric
Generation Expansion Analysis
System)
– Accounts for US style energy market
models
 For
others see reference list at end
CAREC
May 2011
11
Decision Consequences
Value
Generation
Developments
Transmission
Developments
Real-Time
Dispatch
Energy
Market
Time Scale
CAREC
May 2011
12
Transmission System Planning
Issues to consider
 Points
of interconnection
 Type of link
 Link voltage
 Technical design parameters
CAREC
May 2011
13
Types of Link
AC or DC or AC + FACTS
AC Link
Cost
DC Link
Distance
CAREC
May 2011
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Voltage Level

110 kV
 75 MW

220 kV
 280 MW

400 kV
 900 MW

800 kV
 3500 MW
Based on approx Surge Impedance Loading
CAREC
May 2011
15
Technical Issues

Line Rating in conservative scenario

Fault currents arising from new lines & breaker
capacities

Stability
– Transient
– Voltage
– Oscillatory

Switching Overvoltages
CAREC
May 2011
16
Technical Issues
Load Flow

Line Rating in conservative scenario

Fault currents arising from new lines & breaker capacities
Short Circuit Analysis


Stability Stability
– Transient
– Voltage
– Oscillatory
Switching Overvoltages
CAREC
 EMTP
May 2011
17
Transmission Planning Scenarios
 Peak
Demand
 Conservative geographical separation
of demand & generation
 Critical dependency on outage type
– N-1
– N-2
– probabilistic
Investment to be minimised !!
CAREC
May 2011
18
Transient Stability
Power Transfer
Often arises when load & generation
are geographically separated
Unstable Zone
Stable Zone
Max Fault Duration
CAREC
May 2011
19
Schematic Connections of
Software Modules
Data Input
•Network data
•Fixed data
•Variable data
•Etc.
Load Flow
Short Circuit
Stability
RDBMS
Report
System
•Graphical O/P
•Sorted Lists
•File output
Harmonic Analysis
Output to PSSE, CIM,
IEEE Models etc.
EMTP
CAREC
May 2011
RDBMS
20
Typical Main Software Package
Features



Tabular or graphical data input
Network size up to 150,000 buses
Wide range of modules for
–
–
–
–




Load flow
Short circuit analysis
Dynamic analysis
Harmonic analysis
User defined / automated contingency analysis
with corrective actions
User defined software functions
Wide range of data exchange capabilities
Extensive data management & reporting
CAREC
May 2011
21
Deferred Design Matters
 Exact
route of line
 Environmental
 Conductor
 Line
considerations
design
mechanical characteristics
 Tower
type & design
CAREC
May 2011
22
Transmission Planning Packages
 Wide
range of similar packages
– Siemens (PTI) PSSE
– CYME
– Digsilent
– GE PSLF
– ERACS
– etc.
CAREC
May 2011
23
Decision Consequences
Value
Generation
Developments
Transmission
Developments
Real-Time
Dispatch
Energy
Market
Time Scale
CAREC
May 2011
24
Competitive Energy Market
 Many
types – no standard model
 Complex
 Minimum
and costly to establish
size needed for genuine
competition
 Competition
in generation and
customer supply
CAREC
May 2011
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Basic Market Model
GENCO 3
GENCO 2
GENCO 3
GENCO 2
Generation
GENCO 1
GENCO 1
Transmission
Transmission
Transmission
& Distribution
Distribution
Disco 1
Supply Co 1
Disco 2
Disco 3
CAREC
May 2011
Supply Co 2
Supply Co 3
26
Key Players in Market
 Competing
Gencos
 Wires
Company – Transmission (&
Distribution ?)
 Competing
 Market
Supply Companies
& System Operator
 Regulator
CAREC
May 2011
27
Market Activities
Generators
– Offer energy at chosen prices
– Supply energy
– Provide capacity
– Provide support services (spinning
reserve, MVar, frequency control…)
– Respond to System Operator
instructions
CAREC
May 2011
28
Market Activities
Supply Companies
– Procure energy at best rates
– Supply energy to customers
– Negotiate for ‘Top-up’ or ‘Spill’
CAREC
May 2011
29
Market Activities
‘Wires’ Company
– Maintain & operate transmission (&
distribution) system
– Construct new facilities as agreed with
Market Operator
CAREC
May 2011
30
Market Activities
Market Operator
– Forecast daily load (with Supply Companies)
– Conduct bidding process to derive generation
schedule for next period
– Acquire system support services
– Maintain security and reserve margins
– Set market prices for energy & capacity
– Inform Gencos of forthcoming schedule
– …………….
– Operate Settlement System
CAREC
May 2011
31
Market Activities
System Operator
– Accept generation schedule from Market
Operator
– manage operations in real-time, subject
to security, safety & economy
– Monitor and meter energy flows &
services provided
CAREC
May 2011
32
Schematic Market Operations
Offers
Initial
Demand
balance
Sched
of Gen
Settlement
Market Operator
System Operator
Real
Time
Dispatch
CAREC
May 2011
Meterin
g data
33
Decision Consequences
Value
Generation
Developments
Transmission
Developments
Real-Time
Dispatch
Energy
Market
Time Scale
CAREC
May 2011
34
Real-Time Software
 Known
as SCADA (Supervisory
Control & Data Acquisition)
 Employed by System Operator to
implement market allocation
decisions
 Supplemented by ‘Energy
Management System’ (EMS)
 Also used by Discos
CAREC
May 2011
35
Real-Time Software

Largely based in Control Centre

Data collection / command output
processors in each major
substation and generating station

Extensive IT network
CAREC
May 2011
36
SCADA Scheme
Control
Centre
Telecom
Network
S/S 1
RTU
S/S 2
RTU
S/S 3
RTU
S/S 4
RTU
Gen 1
RTU
Gen 2
RTU
RTU: Remote Terminal Unit
CAREC
May 2011
37
SCADA Functions
 Monitor
breaker status
 Monitor line amps & volts
 Supervise alarms in substation
 Control breakers
 Control tapchangers
 Control generator output levels
 Supervise telecoms network
CAREC
May 2011
38
IT Platforms and
Indicative Pricing
CAREC
May 2011
39
Hardware / Software Mixes
Package
Platform Hardware
Generation Planning
PC or shared server
Transmission Planning
PC or shared server
Market System
Complex IT network (some
hardware may be
independently sourced)
SCADA
Complex IT network (some
hardware may be
independently sourced)
CAREC
May 2011
40
Indicative Pricing
Generation Planning
– Annual License: WASP-IV is free
Transmission Planning
– Annual time-constrained license: $6,000+
per user
– Purchase: $18,000 - $40,000 per user
SCADA
– Purchase: $150,000 + hardware + RTUs +
telecoms
CAREC
May 2011
41
Transmission System Planning
Limited Feature / Capacity PSSE and CYME
available at approximately
$5,500 purchase
CAREC
May 2011
42
Thank you
Any questions ?
CAREC
May 2011
43
References
General
Generation
Planning
http://energy.plan.aau.dk/links.php#National_and_Region
al_Energy_System_Analysis_Models
WASP
http://www-pub.iaea.org/MTCD/publications/PDF/CMS-16.pdf
EGEAS
http://my.epri.com/portal
PSSE
http://www.energy.siemens.com/hq/en/services/powertransmission-distribution/power-technologiesinternational/software-solutions/
http://www.digsilent.de/Software/PowerFactory_Applications/Tran
smission/
http://www.gepower.com/prod_serv/products/utility_software/en/
downloads/pslf05.pdf
Digsilent
GE PSLF
CYME
http://www.cyme.com/
SCADA
http://www.energy.siemens.com/us/en/automation/power-transmissiondistribution/control-center-and-energy-management-solutions/spectrumpowercc-energy-control.htm
http://www.alstom.com/grid/fr/electricScada/
http://www.abb.com/industries/db0003db004333/c12573e7003305cbc12570
2600386176.aspx
http://www.gepower.com/prod_serv/products/scada_software/en/xa21.htm
CAREC
May 2011
44
List of Abbreviations
CIM CYME Digsilent Disco EMTP EMS EPRI ERACS FACTS Genco GHG HVDC IAEA IEEE LOLE LOLP MAED PSSE PTI RDBMS RTU SCADA S/S TVA VOLL WASP Common Information Model (IEC 61970) Software from Coopers Electric Software from Digsilent Distribution Company
Electro Magnetic Transient Programme
Energy Management System
Electric Power Research Institute
Software package from ERA (UK)
Flexible AC Transmission System Generating Company Green House Gases
High Voltage Direct Current
International Atomic Energy Agency Institution of Electrical & Electronic Engineers Loss of Load Expectation
Loss of Load Probability
Model for Analysis of Energy Demand – from IAEA Power System Simulation Engineering package from Siemens Original developer of PSSE
Relational Data Base Management System
Remote Terminal Unit Supervisory Control and Data Acquisition Substation Tennessee Valley Authority
Value of Lost Load
Wien Automatic System Planning – from IAEA CAREC
May 2011
45
Typical Market ..1 of 2
 Gencos
offer energy & capacity in 30
minute blocks
 Bilateral contracts between some
Gencos & some supply companies
 Some supply companies provide
energy to non-franchised customers
 Pool bidding scheme operates
between non-franchised customers
and Gencos
CAREC
May 2011
46
Typical Market ..2 of 2
Market Operator manages bidding process
for non-franchised demand
 Market Operator supervises security &
constraints for entire power system
 Market Operator informs Gencos of final
generations schedule
 ……….
 Market Operator manages Settlement
System

CAREC
May 2011
47