modeling for the smarter grid–transcare software provides probabilistic trans reliability current...
TRANSCRIPT
© 2016 Electric Power Research Institute, Inc. All rights reserved.
Roger C. Dugan Sr. Technical Executive
EPRI, Knoxville, TN
Presented at
“Tools for the Smart Grid”
BNL/ISGAN Workshop on Modeling Simulation and More
April 14-15, 2016
Modeling for the
Smarter Grid
2 © 2016 Electric Power Research Institute, Inc. All rights reserved.
EPRI is at the Forefront of Advancing Computer Tools
and Methods for Supporting Utility Grid Planners
Utility grid planners require improved computer tools
– To assess benefits and impacts of solar PV, storage and other DER
There have been advancements in commercially-available
tools within the last decade but gaps remain
– For both transmission grid tools and distribution system analysis tools
– Combined simulation of transmission and distribution
This presentation gives and overview of recent and
continuing research
3 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Topics Addressed in this Presentation
Transmission grid performance with renewables
Probabilistic approaches to planning
– Planners are accustomed to static, deterministic analysis
– Utility planners are often uncomfortable with probabilistic methods
Renewable DER naturally requires probabilistic approaches
Modeling Storage for distribution planning
Quasi-static time series analysis
PV system modeling
DMS modeling
Dynamics analysis for microgrids
4 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Transmission Grid Tool Research
5 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Overview: Distributed Resources & Renewables
Integration to the Bulk System
DOE SUNRISE
Dist PV Integration Assessment
Resource Reliability Capability
Integrated Grid Framework
Forecast Value & Integration
Reserve Determination
System Flexibility Adequacy
Feeder Hosting Capacity
Models for Reliability Analysis & Composite Load Levels
Production Simulation
Model Development
& Testing
Flexibility Analysis/ Adequacy
Utility Threat Identification
Feeder Clustering & Characteri-
zation
Strategic Plan Development
Operational Simulation Tools & Analysis
6 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Issue: Maintain bulk system operational reliability with large
penetration of non-synchronous resources
Key Recent EPRI R&D Results
– DER Ride-Through Req. White Paper / IEEE P1547 Facilitation
– Reliability Contributions White Paper
– Analysis of voltage and frequency performance of BES with DER
– Comparison of various modeling approaches for DER in bulk system studies
Current Work
– DER modeling in BES studies
– Transmission ‘hosting capacity’
– Frequency response with high levels of variable generation
Value
• Understanding implications of
high penetrations of distributed PV
• Bases for planning strategies for high
penetration futures
PV Systems Equivalent Representation
PV Systems Equivalent Representation
Various approaches to model
active distribution systems
• Minimum level of modeling detail
• Data needs
• Automation of creation of
equivalent models
PV Systems Equivalent Representation
Various approaches to model
active distribution systems
• Minimum level of modeling detail
• Data needs
• Automation of creation of
equivalent models
Representative active distribution system (ADS) data
1. Bottom-up construction of
detailed ADS
2. Bottom-up construction of
equivalent ADS by clustering of DERs
5. Change of equivalent
impedance in equivalent ADS
4. Satisfactoryvalidation of equivalent
ADS performance?
Validated equivalent ADS with multiple
voltage levels
No
6. Highestvoltage level of unmeshed ADS
reached?
Yes
No
Equivalent ADS of certain voltage level(s)
Yes
7. Connect equivalent ADS to
detailed ADS of next higher voltage level
3. RMS simulation of detailed and equivalent
ADS and comparison of results
HV
MV
eHV
Load
MV
Load LVRT
PF100
LV
LV
Load
PF100
aRCI NEW
NEW
LVRT
NEW
PF100 LVRT
PF095 NEW
PF100 aRCI
NEW
PF100
PFPOW
PF100
NEW
HV
HV
HV HV
eHV
Load
HV
CHP / Bio
Wind
Photovoltaic
Class
Class specifies
the fault behviour
Primary voltage active distribution system equivalent
Secondary voltage
active distribution
system equivalent
n
2
3
4
Measurement
location
1
Fvl
vrrecov
FvhVt3Vt2Vt1Vt0
Fvl
frrecov
FvhVt3Vt2Vt1Vt0
:
:
Pext
Pref
Pdrp
Vt
It
Qref
Freq_ref
Freq
Ddn Pdrp
11 + sTg
11 + sTg
FvhFfh
FvlFfl
+
++
+
+
+
+N
N
D
D
Ipmax
0
Iqmax
Iqmin
XC
fdbd
0.01
QmxQref
QmnV0 V1
Dqdv
Ipcmd
Iqcmd
Ip
Iq
It = Ip + j Iq
Q Priority (Pqflag =0)Ipmax = ImaxIqmin = -IqmaxIpmax = (Imax2-Iqcmd2)1/2
P Priority (Pqflag =1)Ipmax = ImaxIqmax = (Imax2-Ipcmd2)½
Iqmin = -Iqmax
-
+
7 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Evaluation of DER Impacts
on Transmission Performance
• DER aggregation for bulk system
studies and modeling guidelines
• Interconnection Recommendations
based on system studies
Distributed Energy Resource Impacts on Transmission
PV Systems Equivalent Representation
DOE SUNRISE Strategic
Planning for Distributed PV
• Strategic plan & operational impact
analysis tools for integrating PV
• Southern Company & TVA
• Voltage, Frequency, Flexibility, and
Operating Reserve Impacts
Feeder Hosting Capacity
Models for Reliability Analysis & Composite Load Levels
Production Simulation
Model Development
& Testing
Flexibility Analysis/ Adequacy
Utility Threat Identification
Feeder Clustering & Characteri-
zation
Strategic Plan Development
Operational Simulation Tools & Analysis
8 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Transmission Performance Impacts of Distributed PV
Impact on Voltages :
Delay in voltage recovery
Degradation of load power factor
Change in Active/Reactive
Power Margins
Impact on Frequency:
Reduction in system inertia due
to change in generation mix
PV drop out due to large voltage
disturbance (as per IEEE 1547)
9 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Risk Based Planning
Recent EPRI R&D Results
– Load, Dispatch, & Outage
Uncertainty tool provides Planning
case /probabilities
– TransCARE software provides
probabilistic Trans reliability
Current Work
– Develop grid resiliency
assessment framework
Risk-based planning tools treat
uncertainties to ensure reliability
and economic investment
Illuminate value of transmission
Risk-Based Planning
• TransCARE analysis software
• Load, Dispatch, & Outage uncertainty
model for setting planning cases
• EISPC Risk-Based Planning primer,
application, & R&D gaps whitepaper 7
,250
8,0
00
8,7
50
9,5
00
10
,25
0
11
,00
0
11,7
50
12,5
00
13,2
50
14,0
00
14,7
50
15,5
00
16,2
50
17
,00
0
17,7
50
18,5
00
19,2
50
20,0
00
20,7
50
21,5
00
1
10
100
1000
0
800
1,600
2,400
3,200
4,000
4,800
5,600
6,400
Region Load (MW)
Frequency of Occurence
Renewable Output (MW)
100-1000
10-100
1-10
HILF
Events
Average
System
Conditions
HILF
Events
10 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Scenario Builder Tool to Determine Trans. Planning Cases
across Uncertainties
Gen. & Trans.
Outage Data
Load Variation
(Weather)
Load Variation
(Economic)
Wind & Solar
Variability
Hydro Variability
Demand
Response
Network Model,
Gen. Merit Order &
Dispatch Price
Various Load/Gen.
Dispacth Scenarios
(with probability)
Monte Carlo Draw
Gen. & Trans.
Outages
11 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Integration of Wind/PV
Forecasts into Operations
• Evaluation of Wind/PV Forecast
accuracy and value in operations
• Methods to integrate forecasts into
key operations functions
• Use of Probabilistic Forecasts
Managing Uncertainty in Operations with high VG
Applications of Stochastic
Optimal Power Flow
• Determine operating reserves based
on uncertainty in wind/solar forecasts
• Advanced operational simulation tools
to investigate system operations
• Applying at CAISO and engaging
vendors
0
1000
2000
3000
4000
7/2/20 0:00 7/2/20 12:00 7/3/20 0:00 7/3/20 12:00 7/4/20 0:00
MW
Comparison of Load Following Up Requirements
Dynamic LFU(Load+Wind&Solar) Static LFD LFU_Load Dynamic LFU-Wind+Solar
0
500
1000
1500
2000
2500
3000
3500
7/2/20 0:00 7/2/20 12:00 7/3/20 0:00 7/3/20 12:00 7/4/20 0:00
MW
Comparison of Load Following Down Requirements
Dynamic LFD(Load+Wind &Solar) Static LFD LFD_Load Dynamic LFD-Wind+Solar
12 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Planning Challenges of Renewable Integration
Minimum Load Requirements Base load, non-flexible capacity
Ramping Requirements Continuous ramping
or trough-to- peak shapeable capacity,
including ramping needs in above
normal weather conditions
Flexibility Requirements regulation, load following
capability for forecast uncertainty
and intra-hour variability
Contingency Reserve Frequency responsive,
spin/non-spin capability
1-in-2 peak
demand
forecast
Source: CAISO, Resource Adequacy Flexibility Workshop
12
Future procurement must satisfy operating flexibility in addition to
traditional capacity requirements
13 © 2016 Electric Power Research Institute, Inc. All rights reserved.
EPRI Flexible System Planning R&D
Flexibility Assessment
Software Tool
• Flexibility metrics
• Screening analysis
• Detailed flexibility evaluation
Resource and Transmission
Flexibility
• Resource adequacy considering flexibility
• Transmission and flexibility
• New resource types
Utility/ISO Flexibility
Case Studies
• Insights as to time horizons concerns
• Order of magnitude of possible risk
14 © 2016 Electric Power Research Institute, Inc. All rights reserved.
EPRI flexibility metrics for system planning
Multi-Level Approach – Levels 1 and 2 screening
– Levels 3 and 4 detailed metrics
– Post-processed metrics based on
simulated or historical data
Three detailed metrics: – Periods of Flexibility Deficit
– Expected Unserved Ramping
– Insufficient Ramping Resource
Expectation
Currently benchmarking
various systems – White paper available on epri.com
Level 1
• Variability Analysis & Flexibility Requirement
Level2
• Resource Flexibility Calculation
Level 3
• System Flexibility Metrics
Level 4
• Transmission and Fuel Constrained Flexibility
15 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Situational Awareness
Synchrophasor Applications
Alarm Management Processes
Ops Visualization/Awareness
• Tools to identify most critical Op Limit
and recommendations for Op action
• Operator visualization/awareness of
equipment health & protection status
Improved Operator Awareness &
Decision Making
Improved Real-Time Assessment
16 © 2016 Electric Power Research Institute, Inc. All rights reserved.
R&D effort to examine linking tools across different
domains
System is expected to change at a
faster pace than before
Also greater change in resource
mix – Variable Generation,
Demand Response, Energy
Storage
Consider impact of resource mix
changes on reliability and impact
of reliability constraints on
resource mix buildout
Gaps in long term economics
– Resource adequacy
– Flexibility
– Ancillary services
– Reliable transmission
– Distribution modeling
How to pass relevant info between high level to detailed results??
17 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Distribution System Tool Research
18 © 2016 Electric Power Research Institute, Inc. All rights reserved.
18
Impact of Smart Grid on Distribution System Analysis
(DSA)?
What DSA framework is needed to support all features of the
SG?
Will there be a need for DSA if everything is monitored
thoroughly?
What could we do if we know more about the system?
How will merging of planning, monitoring and DSE change
DSA tools?
19 © 2016 Electric Power Research Institute, Inc. All rights reserved.
19
Key Smart Grid Features
Distributed Resources
– Generation
– Renewable Generation
Variable sources
– Energy Storage
– Demand Response
– Microgrids for Resilience
Communications and Control
– DMS dynamically managing resources, voltage control, etc.
– AMI deployed throughout the system
– High-speed communications to Metering and Controls
– State Estimation
20 © 2016 Electric Power Research Institute, Inc. All rights reserved.
20
DSA State of the Art
Full 3-phase analysis
– Some can do more than 3 phases
Primarily peak demand capacity problem
– A few perform QSTS simulations
Tools designed for uniprocessors
– Mostly satisfactory for now
Support for many SG features is still in embryonic stage
– Inverter modeling
– Storage modeling
– Probabilistic/Stochasting planning
– Dynamics analysis is not common
– LV system ignored
21 © 2016 Electric Power Research Institute, Inc. All rights reserved.
QSTS Simulations
Particularly useful for Solar PV analysis
22 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Inverter Modeling
Short circuit contribution and open-circuit overvoltages
remain an concern for distribution planners
R
R
De
P, Q, I
P, Q, I
V
P, Q, I, V P, Q, I, V
De
De
De
De
De
De
De
De
De
De
De
I I I II I
Quasi-static Time Series Simulator (OpenDSS)
Norton Equivalent
Thevenin Equivalent
Non-linear Time-varying Model in C-Language DLL
Electric Power System
Inverter
University of Pittsburgh testing
and modeling results
23 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Storage Modeling
% Eff. Charge/DischargeIdle | Discharge | Charge
Idling Losses
kW, kvar
kWh STORED
Other Key Properties
% ReservekWhRatedkWhStored%StoredkWRated
etc.
Storage
Controller
Storage “Fleet”Substation
V, IComm Link
-500
0
500
1000
1500
2000
0
1000
2000
3000
4000
5000
6000
7000
8000
1 1441
Demand_wPV+Storage
Demand_wPV
Storage Ouput
PV Output
De
ma
nd
(k
W)
PV
an
d S
otr
ag
eO
utp
ut
(kW
)
Minutes
Charging
Discharging
24 © 2016 Electric Power Research Institute, Inc. All rights reserved.
EPRI vision
Planning and DMS will converge into one set of tools
– (Real time monitoring/control and planning will merge)
– Emphasis of new EPRI research program
Current research into modeling DMS algorithms …
25 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Modeling DMS with Python-based “Sandbox”
Distribution Management System
(Python Script) _
Measurements - voltage at end of each feeder
- voltage at regulators
- regulator taps, capacitor states
Sandbox Module
• Interfaces with simulated
circuit model in OpenDSS
• Monitors control actions
and can restore circuit to
original state after DMS
trial simulations
• Simulates both field
circuit and test cases
• Tracks and records
results to output file over a
time-based simulation
PV var settings
Capacitor override
Regulator voltage setting
OpenDSS
Engine Script
Parameters: relative importance
of each objective
Identify possible
remedies
to simulate
Evaluate
conformity to
objectives
Trial Solutions
26 © 2016 Electric Power Research Institute, Inc. All rights reserved.
Together…Shaping the Future of Electricity