Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
Advancements in Distributed Power
Flow Control
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
Agenda
• Chapter 1 – ENSURE
• Overview & Concept
• Test system and scenario setup
• Exemplary simulation results
• Violation of network restrictions
• Chapter 2 – IDEAL
• Motivation
• Agent based power flow control
• Laboratory setup
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
CROSS VOLTAGE LEVEL POWER FLOW
CONTROL
Chapter 1 | ENSURE
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
Control
Center
Transmission
Grid (TG)
Sub-
Transmission
Grid (STG)
Distribution
Grid (DG)
Sub-Transmission Grid
Control System (STG-CS)
Flexible
Load
! Line Overload
∆Pref
∆Pref
Pmeas
Pmeas
PP
P
P
P
P
∆Pref
∆Pref
!
50 Hz
f
Pref
Pref
Psched
∆Pref
Psched
∆Pref
Psched
•Shut-down of the conventional power plants
• Increase of volatile and distributed generation
Pmeas
•New strategies for system control are necessary
•Possible approach: Control power flowsbetween several voltage levels
•The STG-CS uses DERs connected to the STG and subordinated DG-CSs as actuators
•The DG-CSs uses DERs connected to the DG as actuators
Distribution Grid
Control System (DG-CS)
Conventional
Power Plant
Measurement
Setpoints (transfer rate in
the range of seconds)
Schedules (transfer
rate e.g 15 min)
Frequency
Deviation
Distributed Energy
Resources (DERs)
ENSURE | Overview & Concept
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
ENSURE | Test system and scenario setup
PL
• Dynamic simulations in Matlab-
Simulink to proof concept
• The System is in initial state at
t=0s
• In DG2 the load increases by
10 MW at t=1s
• Case I: DG2 is able to compensate
the change of load independently
• Case II: In DG2 is not enough
flexibility available to compensate the
loadstep independently
Feeder 1 of the CIGRE MV benchmark network
HV-CSSTG-CS
DG-CS
1
DG-CS
3
DG-CS
2
PFlex DG1
PFlex STG
PFlex DG2 + Loadstep
PFlex DG3
13 MW 13 MW
13 MW
10 MW
4 MW 4 MW
4 MW
7 MW
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
ENSURE | Exemplary simulation results – Case I
PL
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
ENSURE | Exemplary simulation results – Case II
PL
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
STG-CS
ENSURE | Violation of network restrictions
• The CS is blocked when
network restrictions are violated.
• The CS restarts operation when
problems are solved.
• How could congestions in future
electrical power supply system
be solved?
!Line Overload
DG-CS
1
DG-CS
3
DG-CS
2
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
Chapter 2 | IDEALAGENT BASED CURATIVE CONGESTION
MANAGEMENT
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | Motivation
• Curative congestion management:
• Operating lines closer to their capacity limit
• Enabling higher utilization of available transmission capacity
• Use of distributed power flow controllers and flexible infeed from active distribution networks
• Agent based approach:
• Distributed control algorithm
• Autonomous determination of countermeasures
• Support of control center staff
• Validation in laboratory setup:
• Testing interconnection between control center, communication system and power flow controller
• Implementation using commercially available products and industry standards
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
Qflex
PflexQflex
Pflex
Control
Center
Control
Center
Sub-
Transmission
Grid (STG)
Distribution
Grid (DG)
G
G
Distributed Power
Flow Controller
Smart Telecontrol
Unit in STGState Inform
Message
State Inform Message &
Negotiation of Actions
Measurements
& Setpoints
Information Flow & Decision MakingHardware Components
Flexible
Load
G Flexible
Generator
Agent
DPFC
Setpoint
G
G
!
!Line
Overload
Smart Telecontrol
Unit in DG
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | MAS information flow
State Inform Message:
- Contains:
- line loading,
- Impedance
- connected nodes
• Information is exchanged
periodically between
agents
• Distribution limited to
relevant agents
Current system state is
known for relevant area to
all agents
Qflex
PflexQflex
Pflex
G
G
Information
exchange
Monitoring and
Decision Making
Decision and
Control Action
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | MAS decision making
Qflex
PflexQflex
Pflex
G
G
Information
exchange
Monitoring and
Decision Making
Decision and
Control Action
!
!
Detection of line overload
Call for proposalResponsible Agent calls foravailable flexibility:- Flexibility of underlying grids- Available PFC flexibility
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | MAS decision making
Qflex
PflexQflex
Pflex
G
G
Information
exchange
Monitoring and
Decision Making
Decision and
Control Action
!
!
Line overload present
Choosing flexibility accordingly:- PFC flexibility before flexible
loads and generation- Highest sensitivity on
overloaded line first- No additional overloads are
created- DC sensitivities calculated
using information from State Inform Messages2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | MAS executing control actionOption 1: Propose control action to control center (semi-autonomous)
Qflex
PflexQflex
Pflex
G
G
Information
exchange
Monitoring and
Decision Making
Decision and
Control Action
- Send proposal to controlcenter
- Assessment of proposal bycontrol center staff
- Activation of flexibility bycontrol center
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | MAS executing control actionOption 2: Autonomous execution of control actions
Qflex
PflexQflex
Pflex
G
G
Information
exchange
Monitoring and
Decision Making
Decision and
Control Action
- Activation of control actionby agent
- Send information ofperformed control action to control center
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | Simulation setup: New England Test System
• Power Flow Controller installed
on line TL0415
• Active Distribution Network at
Node 5 and 15
• Line outage on TL0506 causes
overload on TL 0414
• Overload resolved by
countermeasures determined
by MAS
• Use of power flow controllers
and flexibilty from active
distribution networks
25
2
1
39
9
8
7
6
5
4
3
18
26
29
28
L05
L08
L07
L39
11
10
13
12
14
15 19
20
16
17
2427
2322
21
G
G08
G
G10
G
G01
G
G02
L03
L04
L25
L18
L26
G
G09
L29
L28
G
G03
L15
L20 G
G05
G
G04
G
G06
L21
L23 G
G07
L16
L12
L27
TL0414PFC
ADNADN
Qflex
Pflex
Qflex
Pflex
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | Exemplary Simulation resultsOutage of line TL0506 at t=5s
0
20
40
60
80
100
120
140
0 5 10 15 20
Lo
ad
ing
(%)
Time (s)
Loading of line TL0414
-120
-100
-80
-60
-40
-20
0
20
0 5 10 15 20
ΔP
(M
W)
Time (s)
ADN Flexibility
0
20
40
60
80
100
0 5 10 15 20
Lo
ad
ing
(%)
Time (s)
Loading of line TL0405
-100
-80
-60
-40
-20
0
20
0 5 10 15 20S
et
Po
int(
-)
Time (s)
Power Flow Controller
No Control MAS
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | Laboratory Setup: Real-time simulation and Power
hardware-in-the-loop
19
Real-time digital simulator OPAL RT
eMegasim simulation software
IEC 104 measurement transmission
Analog signal output
Power amplifiers
200 kVA
AC, DC operation
Voltage & Current mode
Internal measurement system (4 µs minimum delay)
Real-time Simulator 200 kVA Power Amplifiers
Busbar Cabinet SFP Communication SYSLaboratory2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
IDEAL | Laboratory Testbed
Control CenterPSI Control
Real-Time Simulator
Power Amplifier
Impedance ControllersSmart Wires Powerline Guardian
Control actions and measurements
Grid Model and MAS
PSI STUs (Agents)
Control actions and measurements
Simulated Elements
Hardware Elements
IEC 60870-5-104 Communication
Non-Standardized Communication Protocol
Conntroller Set Points
2nd FEPSET Champéry 2019
Prof. Dr.-Ing. Christian Rehtanz | Champéry, 08.02.2019
Conclusion and Outlook
Accomplishments:
• Distributed generation can be controlled to follow scheduled power flows at
interconnection points
• Multiagent Sytems can be implemented to use power flow controllers and flexible load and
generation for corrective congestion management
Next steps:
• Integration of agent based congestion management and control of distributed generation
Increased autonomous grid operation relieves grid operators and enables high shares of
renewable energies
• Consider real world and market conditions!
2nd FEPSET Champéry 2019