1 Real Time Digital Simulation RTDS ® Power Systems Simulation in Real Time.
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Transcript of 1 Real Time Digital Simulation RTDS ® Power Systems Simulation in Real Time.
1
Real Time Digital Simulation
RTDS®
Power Systems Simulation in
Real Time
2
RTDS Technologies Inc.Company:
• Based in Winnipeg, Canada
• Established in 1994
- 40 °C
3
History:
• Manitoba HVDC Research Centre (1980s)
• Funding from Manitoba Hydro
• World’s 1st real time digital simulator
• 1st commercial installation in 1993
• Created a independent company - RTDS Technologies in 1994
RTDS Technologies Inc.
4
RTDS Technologies:
• over 100 installations• over 400 units• 23 countries• clients include leading …
– electrical power utilities– electrical equipment
manufacturers– research and learning
institutions
RTDS Technologies Inc.
5
RTDS Technologies Inc.RTDS Simulator Users:
Electrical power utilities
Electrical equipment manufacturers
Research and learning institutions
% of Clients per Sector
32.38%
37.14%
30.48% % manufacturers
% research
% utility
% Racks per Sector
33%
27%
40% manufacturer
research
utility
6
Real Time Digital Simulation
• Electromagnetic transient solution (EMTP type simulation)
• Based on the Dommel algorithm• Trapezoidal rule of integration• New solution produced each timestep
• Continuous hard real-time response must be achieved and sustained if physical control and protection equipment is to be included in the simulation study
• Dedicated high speed processing and signal communication required to achieve real-time
• The RTDS Simulator• A combination of specially designed parallel
processing hardware and detailed, efficient solution algorithms
RTDS Technologies Inc.
Page 7
Time scales of power system phenomena
10-7 10-5 10-3 10-1 101 103 105
Lightning
Switching
Subsynchronous resonance
Transient stability
Long term dynamics
Tie-line regulation
Daily load variation
Timescale (seconds)
HVDC, FACTS, etc.
Generator control
Protection
Prime mover control
LFC
Operator actions
1 cycle 1 sec 1 min 1 hr 1 day
Impulsive transients
Oscillatory transients
Short-duration variations
Long-duration variations
Imbalance, harmonics, inter-harmonics, notching, noise
Voltage fluctuations
Frequency variations
Electromagnetic transient modeling and simulationElectromagnetic transient modeling and simulation
8
RTDS Technologies Inc.Simulation Techniques:
Loadflow & Short Circuit50/60 Hz only
Transient Stabilitysimulation cannot
capturesubsynchronous
phenomena.
~0 Hz
Electromagnetic Transients - EMTP/EMTDC/ATP
Special Models andSmaller Timesteps
Region often neglected by non-real timeelectromagnetic transient simulations
(short duration simulations)
Frequency
Real Time Electromagnetic Transients - RTDS
0 Hz to 2-3 kHz (dt = 50 us)
Continuous real time simulationscover the entire frequency range
?
0 Hz to 2-3 kHz (dt = 50 us)
~50/60 Hz
RRLBRK
BRK
0.1 [H]
1.0 [uF]
0.1 [H]
1.0 [uF]
Capbank : Graphs
0.100 0.150 0.200 0.250 0.300 0.350 0.400 0.450 0.500 ... ... ...
-300
-200
-100
0
100
200
300
kV
Vcap
-2.00
-1.50
-1.00
-0.50
0.00
0.50
1.00
1.50
2.00
kA
RLIa RLIb RLIc
Transients and Steady State
• Transient solution
– Harmonics– Non-linear effects– Frequency
dependent effects
• Steady state solution
– RMS Value
• Transient – High frequency
– Damped (short duration)
RRLBRK
BRK
0.1 [H]
1.0 [uF]
0.1 [H]
1.0 [uF]
Capbank : Graphs
0.190 0.200 0.210 0.220 0.230 0.240 0.250 0.260 ... ... ...
-300
-200
-100
0
100
200
300
kV
Vcap
-2.00
-1.50
-1.00
-0.50
0.00
0.50
1.00
1.50
2.00
kA
RLIa RLIb RLIc
Transients and Steady State
Transients and Steady State
1 unit 80 MVA
1 unit = 150 MVA
#1 #2
VTIT 3
IfEfEf0
Vref
Exciter (ST3A)
Vref0
Ef0
W2
S2M
S / Hinhold
out
TM01
1.0D -
F
+
W2
*13.333
G1 + sTD -
F
+
G1 + sT
S / Hinhold
outTM01
L2N
P+jQ
#1 #2
Ia
L2N
TM0
S / Hinhold
out
G1 + sTD -
F
+
G1 + sT
*13.333
W
D -
F
+
#1 #2
Neuclear plant : Con...
P1
25.4618
Q1
66.1229S
Te
3
AV
Tm
Tm0
Ef0
Tmw
Ef If
1.0
TM0
S / Hinhold
out
S2M
TIME
TIME
S2M
L2N
W
Ef
P = 25.46Q = 66.12V = 1.004
VA
E132
Ef0
VTIT 3
IfEfEf0
Vref
Exciter (ST3A)
Vref0
Ea
TLine_01
P = 143.8Q = 76.1
V = 1.003
VA
STe
3
AV
Tm
Tm0
Ef0
Tmw
Ef If
ABC->G
TimedFaultLogic
TLine_02
BR
KB
RK
OOS Investigation
x 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 ... ... ...
0.970
0.980
0.990
1.000
1.010
1.020
1.030
1.040
1.050
1.060
1.070 W W2
-150
-100
-50
0
50
100
150
200
250
300 P1 P2
-1.50
-1.00
-0.50
0.00
0.50
1.00
1.50 E132
Transient stability problem• Fault / clearance
• Slow Transients (electro-mechanical)
• Electrical transient occurs when there is a rapid exchange or flow of energy from one element to another
– Interaction of energy stored in electric fields of capacitances and magnetic fields of inductances in electrical power systems
– Initiated by a change to the network topology (connections)
• Switching Events
– Opening and closing
• Faults
– Inception and clearance
• Lightning
• Others
Electromagnetic transients
RRLBRK1
0.001 [H]
3
BRK
#1 #2TLine1
T
Ea Eb
#1 #2
OpenMain : Graphs
0.170 0.190 0.210 0.230 0.250 0.270 ... ... ...
-300
-200
-100
0
100
200
300
y
Ea
Main : Graphs
0.170 0.190 0.210 0.230 0.250 0.270 ... ... ...
-300
-200
-100
0
100
200
300
y
Eb
Electromagnetic transients
Basic R-L-C networks
0.005 3BRK 1
RL
10.0
1/[2(pi).SQRT(LC)] =1.299 kHz
0.1950 0.1975 0.2000 0.2025 0.2050 0.2075 0.2100 0.2125 0.2150 ... ... ...
-4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0
Ic
-300
-200
-100
0
100
200
300 Ec
Oscillatory transients:
• Both L and C involved
• Damping is due to resistance
• System losses• Loads
Load Flow / Transient Stability • Each solution based on
phasor calculations
Electro-Magnetic Transients
• Direct time domain solution of Differential Equations
Transient vs. Steady State
R L
I
R=
0 V
• Period of natural frequency is about 1.5 ms• Period of natural frequency is about 1.5 ms
Time StepTime Step
HL 0.11 000,1001R FC 05.02 005.012R
e v1 v2
L1
R1
R12
C2
i2
i1
• Time step of 1.0 ms• Time step of 1.0 ms
Time StepTime Step
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
0 0.01 0.02 0.03 0.04 0.05
Time (s)
• Time step of 5 micro-seconds• Time step of 5 micro-seconds
Time StepTime Step
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
0 0.007 0.014 0.021 0.028 0.035 0.042 0.049
Time (s)
• Time step of 70 micro-seconds• Time step of 70 micro-seconds
Time StepTime Step
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
0 0.007 0.014 0.021 0.028 0.035 0.042 0.049
Time (s)
20
Simulation:
Non Real Time:• Simulation of the system’s response over 1 second may require several
seconds or even minutes of computer time
• Wide range of available non real-time programs (PSCAD, EMTP, etc.)
• Solution speed is not hard real-time, hence interpolation can be used in large closely connected networks with numerous switches
Real Time:• Simulation of the system’s response over 1 second must be completed in
exactly 1 second.
• Hard real-time provides equidistant updates from each timestep
Non Real Time vs. Real Time
21
实时仿真Real Time Simulation
• 实时:仿真系统中完成一个物理现象的时间与电力系统中完成该现象的时间完全一样;
• 时间域中的电磁暂态分析;• 实时仿真应在所仿真的整个系统,而不是在部分的仿真系统进行;• 实时仿真应能连续地长时间进行;• 实时仿真装置应能与实际的电力系统元件(例如与控制保护系统)相连
接来完成闭环试验或是能在电力系统中运行;• Real Time:The time to complete a physical phenomena should be exactly the
same as it happened in a real power system;
• It is in time domain, electromagnetic transient analysis;
• The real time simulation is in full simulated system, not in part of the simulated system;
• The real time simulation can operate continuously;
• The real time simulation can connect to the real power system equipments ( e.g. relay or control system) for a close loop test or can operate in the power system;
22
动模与数模仿真Analog and Digital Real Time Simulations
• 两种实时仿真:– 动模与数模
• 三个时间里程碑:– 1880 年代, 1970 年代, 1989 年
• 动模在世界上已有百年的历史,在国内至少有 50 年历史 ;• 实时数字仿真只有 19 年历史 ;• 目前实时数字仿真的安装地点约为动模的一倍 ; 仿真规模在数十倍以上;• Two Kinds of Real Time Simulation:
• Analog and Digital • Three Milestone Years:
• 1880’ 1970’ 1989• Analog Real Time Simulation Has 100 year’s History worldwide and more than 50
Year’s History in China• Real Time Digital Simulation Has only 19 year’s History • Digital/Analog : The Location Number: 2 , Simulated Scale: Tens Times
23
国外实时数字仿真的里程碑(供讨论)Milestone of Real Time Simulation (for
discussion)• 美国国家专利 2323588, Waldo E. Enns 交流网络仿真装置,申请 1940.11.6. 批准
1943.7.6 ;• IEEE 论文 Hermann W. Dommel 教授 ,1969.4.4.
– 单相和多相网络中电磁暂态的数字仿真
• 世界上第一台实时数字仿真装置诞生: 1989 年, Manitoba HVDC 研究中心( RTDS 技术公司) ; Dennis Woodford, Rick Kuffel, Rudi Wiercks, Trevor Maguire, James Giesbrecht
• US Patent 2323588, Waldo E. Enns, Applied 1940.11.6 , Approval 1943.7.6
– Apparatus for A.C. Network Analysis
• IEEE Paper April 4, 1969, Hermann W. Dommel
– Digital Computer Simulation of Electromagnetic Transient in Single-and Multiphase Networks
• Manitoba HVDC Research Center (RTDS Tchnologies Inc), 1989, Dennis Woodford, Rick Kuffel, Rudi Wiercks, Trevor Maguire, James Giesbrecht
– The Birth Day of First Power System Real Time Digital Simulator Worldwide
24
经验与教训(一)What We Learned from the History Review (1)
• 电力工业的发展是实时仿真的主要推动力 ;
• 科技的进步是实时仿真的基础(电工理论基础,电力系统理论和技术以及计算机技术) ;
• 正确的技术路线和市场化 ;
• 坚持不懈的研究与开发 ;
• The Real Time Simulation Is Driven by The Development of Electric Power Industry;
• Science & Technology’s Progresses are the Base of the Real Time Simulation (Theories & Technologies of Electric and Computer);
• Right Technical Plan/Path and Marketing;
• Continue R&D;
25
经验与教训(二)What We Learned from the History Review (2)
• 如同任何其它历史(经济,技术,政治等等)实时仿真的历史也有历史的创造者,推动者和见证者– - 今天每一个人都可以为自己参与了这个实时仿真的技术发展史而自豪
• 回顾历史可以让我们知道自己从何而来,现在何处,以及将要去往何处。– - 实时仿真技术从发展至今尚处成长期,它值得我们为其努力。
• As Other Histories (Economy, Technical etc), Real Time Simulation Technology Has Its History Creators, Promoters and Witnesses. – Every Body in This Room Can Proud For His Involving In This History
• Review History Let Us Know Where We Are From, Where We Are and Where We To Go:– Real Time Simulation Technologies Are Still Growing. It Is Worth For Us to
Continue Work For It.
26
对未来应用的建议Suggestions For The Applications in Near Future
• 继续为交直流大电力系统服务仍是一段时期内实时仿真的主要方向 ;• 重视实时仿真在再生能源和负荷管理的应用 ;• Continue Work for the AC/DC Power Systems• Put Attention to Renewable Energy and Demand Management
27
RTDS
Simulation
Hardware
28
RTDS Hardware:
• Custom parallel processing computer
• Hardware is modular, allowing users to increase computing capability as required
• Main interface with the hardware is through user-friendly software
• Ample, convenient input and output allowing connection of physical devices
Simulation Hardware
29
A Rack:
A unit of hardware is called a ‘Rack’ and typically includes:• 1~6 RISC Processor Cards (GPC)• 1 Inter-Rack Communication Card (IRC)• 1 Workstation InterFace Card (WIF)
Simulation Hardware
30
Parallel Processing – Sharing the burden of calculation:
Simulation Hardware
> t
31
Small Scale Simulations:• Reduced # of processors• Transportable to site
Large Scale RTDS Simulations:• Large scale studies• Complex simulation case• One large or several smaller
simultaneous simulations
Simulation Hardware
32
Simulation HardwareModular Hardware:
• Easy expansion• Maximum availability• Easy maintenance• Full Compatibility
Processing power
GPC
33
Simulation HardwareCustomer Driven Development:
Giga Processor Card - GPC:
• Introduced January 2005
• Additional Power utilizing two IBM 750GX Power PC’s each running at 1 GHz
• Multiple timestep operation supported
3PC RPC GPCProcessor ADSP 21062 IBM PPC750CXe IBM PPC750GXPrecision 40-bit 64-bit 64-bitProcessors per card 3 2 2
MFLOPS per processor 80 600 1000MFLOPS per card 240 1200 2000( MFLOPS = millions of floating-point operations per second )
34
Simulation HardwareRISC Processor Card (GPC):
• GPC Network Solution– 1 GPC processor handles 54 nodes
in a single lumped circuit, as well as 12 embedded valve groups
– presently dimensioned for 56 single-phase switches (i.e. breakers and/or faults)
TPC 3PC GPC27 6 0.5
No. of cards required to perform solution of 54 node network
35
36
37
Workstation InterFace Card - WIF:
• Each rack contains a single WIF with its own unique Ethernet Address
• Connects to workstation via standard Ethernet LAN
• Provides timestep clock
• Provides communications to load, start and stop simulation case
• Enables user interaction with simulation
• Provides data exchange coordination and data record capability
Simulation Hardware
38
Workstation InterFace Card - WIF:
• 50 MHz MPC860T/DT processor
• 10/100 Base TX Ethernet interface
• 1 million point plot memory
• Bus logic to control local rack simulation
• Global bus for Multi-rack simulation
• RS-232C Diagnostic/Configuration Port
• LED display on the faceplate to show configuration information
Simulation Hardware
39
Inter-Rack Communication Card - IRC:
• Connection via RJ-45 jack
• Connection paths which mimic the power system
• No need to change connections
• High speed communication between racks
• Direct connection to six other racks
Simulation Hardware
40
Flexible and Expandable I/O for the GPC:
•GTAI (12 channel, isolated 16-bit analogue input card)
•GTAO (12 channel, isolated 16-bit analogue output card)
•GTDI (64 channel, isolated digital input card)
•GTDO (64 channel, isolated digital output card)
•GTFPI (interface to digital and high voltage interface panels)
•GTNET (Ethernet Interface System)
The GT family of I/O cards can be daisy chain connected to a single GPC fiber port (fewer GPC cards needed to accommodate I/O connection).
Simulation Hardware
41
High Precision Analogue Output Card - GTAO:
• Twelve (12) synchronized 16-bit output signals per card
• Output range +/- 10 volts peak (0.3 mV resolution)
• Fully compatible for 12 channel update of small timestep (~ 2μs) simulation signals
• Connects to GPC via fiber optic connection – daisy chain connection allowed to other GTIO cards
• Rail mounted with access from rear of cubicle
• Signal selection and scaling in Draft
Simulation Hardware
42
High Precision Analogue Input Card -GTAI:
• 12 channel input card with 16 bit A-to-D converters
• Provides optical isolation of input signals from external devices to the RTDS
• Interfaces to GPC via fiber optic connection
• +/- 10 V true differential analog input
• Connects to GPC via fiber optic connection – daisy chain connection allowed to other GTIO cards
• Rail mounted with access from rear of cubicle
• Signal selection and scaling in Draft
Simulation Hardware
43
GPC Digital Input - GTDI:
• Required for digital input to small timestep simulations
• 64 digital input signals per card
• Connects to GPC via fiber optic connection – daisy chain connection allowed to other GTIO cards
• Rail mounted with access from rear of cubicle
• Signal selection in Draft
Simulation Hardware
44
GPC Digital Output - GTDO:
• Required for digital output to small timestep simulations
• 64 digital output signals per card
• Connects to GPC via fiber optic connection – daisy chain connection allowed to other GTIO cards
• Rail mounted with access from rear of cubicle
• Signal selection in Draft
Simulation Hardware
45
GPC Front and High Voltage Panel Interface - GTFPI:
• Interface to 16 digital input and 16 digital output low voltage channels
• Interface to 16 dry contacts
• Connects to GPC via fiber optic connection – daisy chain connection allowed to other GTIO cards
• Rail mounted with access from rear of cubicle
• Signal selection in Draft
Simulation Hardware
装置开关输出回路接线图
开关量输出回路
47
GPC Network Communication - GTNET:
• GTNET – GSE IEC 61850 binary messaging
• GTNET – SV IEC 61850-9-2 sampled values
• GTNET – Playback very large data playback
• GTNET – DNP DNP SCADA interface
Simulation Hardware
48
Digital Interface Panel:
• Interconnect signals between the RTDS external equipment
• 16 digital input and 16 digital output via 4mm banana plug adapters mounted on front of the cubicle
• Signals from the GPC connect to the digital interface panel via the GTFPI card
Simulation Hardware
49
High Voltage Interface Panel:
• 16 solid state contacts rated for up to 250 Vdc
• Used to send status signals from the RTDS Simulator to external equipment at station level voltage (max. 250 Vdc)
Simulation Hardware
50
Amplifiers:
• External amplifiers are used to provide secondary level voltages and currents
• Amplifiers are connected in the test loop between the RTDS Simulator and the equipment under test
• Various amplifiers solutions have been used (Omicron, Analogue Associates/Techron/Crown, Doble, etc.)
Simulation Hardware
51
RTDS
Simulation
Software
RTDS Technologies Inc.
52
RTDS Software:
Graphical User Interface • RSCAD
Power and Control System
Software• Component Model Libraries &
Compiler
Simulation Software
53
RSCAD Graphical User Interface:
FILEMAN TLINE RUNTIME
DRAFT CABLE MULTIPLOT
Simulation Software
54
RSCAD Graphical User Interface Software:
• JAVA Based• Runs on PC under Windows and on
Sun Workstation under Unix• Single line diagram drawing format• Hierarchy structure for circuit layout• Integrated Load Flow• Software can be installed on any
number of customer computers• PSS/E conversion function
Simulation Software
55
Circuit Construction in RSCAD / DRAFT:
• Circuit assembly
• Data entry
3 phase drawing models single line drawing mode
Simulation Software
56
Component Editing:
Simulation Software
57
Running the Simulation in RSCAD / RUNTIME:
• True real time performance provides ability to operate the simulated power system interactively
• Simulator control
• Monitoring
• Data acquisition
• Manual mode
• Automatic mode
Simulation Software
58
Automated Batch Mode Testing:
• Script file– High level programming language with
C like structure– adaptive via if, for, and while statements– user-defined subroutines– customize reporting of result analysis– automated plot printing
• Efficient means of running numerous cases
Simulation Software
59
Comprehensive library of component models available:
Power System Control System
Component Model Library Component Model Library
Simulation Software
Machine Models
• The simplest model is that of a constant speed ( frequency) machine consisting of an ideal voltage source behind an appropriate impedance. For an electromagnetic transient study this would most likely be the machine subtransient reactance.
E`` X``
This type of machine model would be appropriate in a study
where the transmission line being protected was represented
by lumped impedances and the time scale of interest was several cycles. The relay bandwidth would be restricted to 50/60Hz and dc offset components. e.g.
jXE``
jX``R
Machine
jx
Trans. Line Infinite BB
RRelay
For longer time periods involving possible power swings then the transient reactance would replace the subtransient reactance and the machine inertia would have to be represented by at least a single equivalent mass. The moment of inertia, J, is for both the turbine generator and exciter combined.
X`
E`
Inertia, JTm
Te
Swing Example
Here is a study involving a full dqo machine model with single
mass inertia and a single pole open and reclose feature at the relay
location R. There are two 100km distributed parameter lines
with a single phase fault half way along one of the lines.
Multi-mass machine models
• Single mass inertia models are probably OK for hydro turbine sets.
• Steam turbines on the other hand have multiple stages (HP, IP, LP) plus the generator and exciter and may be much larger than the hydro sets.
• Shafts have been damaged by mechanical resonances excited by sub-synchronous frequencies on the electrical network.
AVR’s, governors & PSS’s
• In studies where the inertia of the set is relevant then we need to also include other devices which produce effects in the time window of interest.
• Governors are in general very slow except in cases of “fast valving” on a steam set.
• Automatic voltage regulators and Power Sytem Stabilisers will certainly be in play during power swing conditions.
Conclusions
• Choose a model which suits the time scale of interest.
• Where possible, compare any simulation results with recordings to check for model validity.
• Models for internal faults are not generally available and are actively being researched at the present time.
Transformer Models
• Can be modeled in RTDS in three fundamental ways– The Ideal transformer model– The Linear transformer model– The built-in saturable transformer model
Ideal Transformer Model• Ideal Transformer
– Ignores leakage flux• Assumes flux is confined in the core
– Neglects Magnetizing Currents• Assumes no core reluctance
Simple Transformer
+
-
+
-
i1
Ac
V1
i2
V2
N1
N2
Ideal Transformer Equations
V Nd
dt1 1
V Nd
dt2 2
V
V
N
N1
2
1
2
I
I
N
N1
2
2
1
Linear Transformer Model
• In this case the magnetizing branch is included in the model as an inductive branch.
Saturable Transformer Model
• Uses a star-circuit representation
• User could include saturation data
Transformer ModelTransformer Model
n:1n:1IdealIdeal
TransformerTransformer
LsLsRpRp LpLpLmLm RsRs
Volt
ag
eV
olt
ag
e
CurrentCurrent
Operating pointOperating pointfor for current transformerscurrent transformers
Linear regionLinear region
Non-Linear regionNon-Linear region
V-I curve knee pointV-I curve knee point
Transformer V-I Curve CharacteristicTransformer V-I Curve Characteristic
More in Section 10More in Section 10
Saturation voltageSaturation voltage
Operating pointOperating pointfor for voltage transformersvoltage transformers
ii LL
((tt ))
((t -t - t)t)
iiLL(t- (t- t) t)
slopeslope
knkn
Non-linear Element Represented as Non-linear Element Represented as
Piece-Wise Linear Piece-Wise Linear -i-i Function Function
tttttitik LLn iiLL(t)(t)
Saturable Transformer Model
• The model requires as a minimum the following data– The voltage rating of each winding– The leakage impedance of each winding– The transformer connectivity information
Transmission Line Models
• RTDS users must know– What kind of models are available– Applicability of the various models for steady
state or transient studies– Advantages and disadvantages of each model
EMTP Line Models for Steady State Studies
• Line models for steady state studies– Exact-pi model– Nominal-pi model
Exact-Pi Model
• Exact-pi model– It is a lumped-parameter model– The model includes hyperbolic corrections– Frequency independent– Best model for steady state studies
1/Y series
Y shunt /2 Y shunt /2
Exact-Pi Models
• It is a multi-phase line model and it takes into account– Skin effect and– Circuits in the same right-of-way
• Not good for transient studies
Nominal-Pi Model
• Derived from the exact-pi model – Ignores hyperbolic corrections
• Takes into account– Skin effect and
Nominal-Pi Model
• Multi-phase line model
• Frequency Independent
• No time step limitations
• Not good for transient Studies– Could be used if multiple Nominal-pi sections
are cascaded together
Nominal-Pi Model
• Model Limitations– Cannot be Used for “Electrically Long Lines” – Limited to lines with length < 150 Km at 60 Hz– Limited to lines with length < 5 Km at 2 kHz
RTDS Line Models for Transient Studies
• Line models for transient studies– Nominal-pi model– Frequency independent distributed parameter
line model– Frequency dependent distributed parameter line
model
RTDS Line Models for Transient Studies
• Nominal-pi– Not recommended for transient studies– Produces reflections at the cascading points– Computationally expensive– Sections must be kept very short { 5-10 km for
frequencies up to about 2 kHz}
RTDS Line Models for Transient Studies
• Constant parameter distributed line model– Bergeron model– Model assumes that R’, L’, & C’ are constant– L’ & C’ are distributed and the losses R’*l are
lumped in three places– Shunt losses are ignored
RTDS Line Models for Transient Studies
• Frequency dependent transmission line model– Represents accurately the distributed nature of all line
parameters– Frequency Dependent – Transformation matrix is real and constant– Most accurate for use in transient studies
RTDS Line Models for Transient Studies
• The DP and FD models– Use traveling wave solutions and are valid over a
wider frequency range– Require transformations between phase and modal
domain– Keep track of modal waves traveling at different
speeds– When the modal propagation time ( or “travel time” )
of a line is less than the chosen simulation time−step Δt, the line cannot be represented using these general travelling wave models.
Conclusions
• Use pi-exact model for steady state studies
• Use fd-line models for lines of main interest in your study
• Use cp-line models for lines of secondary interest
Section 10 Section 10
Relay Input SourcesRelay Input Sources
npnp CT loadCT load(burden)(burden)
nsns
ipip
isis
BurdenMagnetizingBranch
ip Rp Lp LsRs is
IdealCT
ip’ Rp Lp LsRs isEs
im
imr imx
LmRmRl
ip’ isEs
im
LmRb
Currentsource
1010
100100
10001000
CT ratio error [%]
600/5 A, C100 CTwith 1.5 total load resistance
Ideal CT
10 100 1000
CT Primary Current [A] (referred to the secondary)
CT
Sec
ond
ary
Cu
rren
t [A
]C
T S
econ
dar
y C
urr
ent
[A]
CT Saturation for Symmetric Fault CurrentsCT Saturation for Symmetric Fault Currents
0.1 1 10 10010
100
Exciting Current [A]
Vol
tage
[V
]
1523
3548
7
LmLm is nonlinear inductor, is nonlinear inductor, specified in piecewise linear form specified in piecewise linear form
-I-I data points are not readily available data points are not readily available
ATPATP provides a routine provides a routine SATURATIONSATURATION to to
convert convert VVrmsrms-I-Irmsrms characteristics characteristics
into into -I-I set set
9.2 9.2 Digital Models of Digital Models of
Coupling Capacitor Voltage TransformersCoupling Capacitor Voltage TransformersCCVTCCVT
A CCVT Circuit ConnectionA CCVT Circuit Connection
HV
C
C1
2
L
R
GG C
R RLL
R
G RC
LR
C
L
y
y
R
y
Z
1
2d1
d1
d1
1
2
ps
p
r
2
s
3
b
h
T
F
FF3
a
a
Cp
d1 C C p
p
R
C
L
Cs
s
x
x
x
R
1
3
138kV
5kV/115V/66.4V
SW1
A 138 kV CCVT DesignA 138 kV CCVT Design
Voltage Transformer Voltage Transformer Digital ModelsDigital Models
n:1n:1IdealIdeal
TransformerTransformer
LsLsRpRp LpLp
CpCp
RmRm LmLm RsRs
103
Component Builder:
Simulation Software
104
Applications
RTDS Technologies Inc.
105
Closed-loop testing of protection systems:
Applications
106
Applications
Protection systems test methods:• Synthetic testing
– Typical of test set used for routine testing– No true power system signals used– “Synthetic” waveforms are often unrealistic and in
some cases misrepresent how a relay will function in service
107
Applications
Protection systems test methods:• Playback testing
– Uses recorded or simulated power system signals– Waveforms only valid until the relay trips– Only one relay can be tested
108
Applications
Protection systems test methods:• Closed loop testing
– Requires a real time simulator to provide realistic power system signals
– Closed loop response allows complete interaction between the relay and the simulated power system
– Multiple devices (relays and/or controllers) can be tested as if connected to an actual power system
109
ApplicationsClosed-loop testing of protection systems:
Standard electrical connection
Digital to AnalogueConverters
V VII
Relay #2Relay #1
125 Vdc
Digital I/O Digital I/O
PowerAmps
125 Vdc
PowerAmps
110
ApplicationsClosed-loop testing of protection systems:
Interconnection via IEC 61850 GOOSE and Sampled Values
GTNET - SV
Relay #1
GTNET - GSE
GTNET - SV
Relay #2
STATIONBUS
PROCESS BUS
111
Closed-loop testing of protection systems:
• Proven power system representation
• Advanced instrument transformer models
• Script files for automated testing and customized reporting
• Hardware interface
• Interaction studies providing a true test for multiple relays and other devices
• Suitable for low level testing of single relays and multiple relays
• Flexible amplifier solutions
Applications
........
........
R
Real-Time Digital SimulatorRTDS
DIGITAL INPUT / OUTPUT CHANNELS
1 10 11 12 13 14 15 16
DIGITAL INPUT / OUTPUT CHANNELS
2 543 6 7 8 9
1 10 11 12 13 14 15 162 543 6 7 8 9
RTDS Simulator
Voltage and Current
Amplifiers
Protective Relay(s)
Interfacing to Protective Relays
Amplified Voltages and Currents (Sec. Levels)
Trip and Reclose Signals
Voltage and Current Signals (low level)
112
Closed-loop testing of protection systems:• Manufacturers
• ABB Automation – Sweden • Dong Fang - China• AREVA T&D – England • SiFang - China• Basler Electric – USA • Guodian Nanjing Automation - China• GE Multilin – Canada • LGIS – South Korea• Siemens AG – Germany • NxtPhase T&D - Canada• SEL – USA• TMT&D - Japan
• Utilities• REE – Spain • Guangxi EPRI - China• PG&E –USA • East China EPRI - China• KEPCO – Korea • Fujian EPRI – China• FURNAS – Brazil • Sichuan EPRI – China• CCGroup – China • North China EPRI - China• SEC – Saudi Arabia
• Universities / Research & Test Institutes• China EPRI – China • CPRI – India• Kinectrics – Canada • NTU – Singapore• University of Bath – England • University of Western Ontario – Canada• Wuhan University – China • Xuchang Relay Institute - China
Applications
113
Closed-loop testing of control systems:
Applications
114
ApplicationsTesting of Excitation Controllers:
Static Exciter Test Circuit
MainGenerator
590 MVA22 kV
Per unit conversion8.2 V = 1 p.u.
ControlledRectifier
50 km22 kV : 230 kV
MainGrid22 kV : 560 V
DECS300
V
I
AUX. POWER
AMPS
Low Voltage+/- 10 Vpk.
25 V / V5 A / V
RTDS Simulator
Omicron
Static Exciter
Low Voltage< 24 Vdc.
RTDS Analogue Output
RTDS DigitalInput
115
Closed-loop testing of control systems:
• True real time required
• Large amount of data exchange – 100’s of digital and analogue I/O
channels needed
• Improved firing for power electronics
• Real time network solution – more breakers
• Switched filter component – more breakers with fewer nodes
Applications
From RTDS to Controls
From Controls to RTDS
-commutating bus voltages-dc current & voltage-winding currents-breaker status
-firing pulses-block/bypass signals-control variable monitoring
Interfacing to HVDC Controls
Digital and AnalogueSignals
Digital and AnalogueSignals
116
Commercial Control System Studies:
• HVDC (High Voltage Direct Current)
• SVC (Static Var Compensator)
• TCSC (Thyristor Switched
Series Cap.)
• Generator (Exciter, Governor, PSS)
• STATCOM (3-level, PWM ~1200 Hz)
Applications
117
Closed-loop testing of control systems:• Manufacturers
• ABB Power Systems – Sweden • Fuji - Japan• AREVA T&D – England • Hitachi - Japan• Basler Electric – USA • Kinkei - Japan• Siemens AG – Germany • Medensia – Japan• Nokian Capacitors – Finnland • XJ Corporation
• Utilities• KEPCO – Korea • Fujian EPRI – China• FURNAS – Brazil • South Central Power China - China• Manitoba Hydro – Canada • TNB - Malaysia
• Universities / Research & Test Institutes• CPRI – India • Kinectrics - Canada• BDCC – China • Xian High Voltage Apparatus Research Institute - China
Applications
118
• efficiency of real time• frequency response
from 0-3kHz with one tool• detailed control - power
system interaction investigation
• Ongoing R & D to combine two types of equivalence techniques
ApplicationsGeneral Power System Studies & Education:
119
General Power System Studies & Education :• Utilities
• KEPCO – Korea • Chugoku EPCo – Japan• Kansai EPCo – Japan • Takaoka EPCo – Japan• Tohoku EPCo – Japan • Manitoba Hydro – Canada• BC Hydro – Canada • LADWP - USA
• Universities / Research & Test Institutes• CPRI – India • ChangWon University – South Korea• Clemson University – USA • Florida State University (CAPS) – USA• J Power – Japan • TU Delft / TU Eindhoven – The Netherlands• University of Manitoba – Canada • University of Western Ontario – Canada• University of Wyoming – USA • University of Missouri-Rolla – USA• University of Cassino – Italy • University of Durban – South Africa
Applications
120
RTDS Technologies Inc.
Validation
121
Validation:
• In-house
• Independent validation by customers
• Commercial studies
• Industry benchmark cases Electromagnetic Transient Electromechanical Transient Transient Stability Load Flow / Steady State
Validation
122
Comparisons between RTDS and various references:
• EMTDC, EMTP, and Netomac
Non real time electromagnetic transient simulation
• PSS/E, Y-Method, Netomac, and BPA
Transient stability
• PSS/E, Netomac, and BPA
Load flow
• CIGRE and IEEE
Benchmark cases
• Actual power system measurements
Validation
123
Commercial Studies:
AC DCBus Split Filters
Loads
220 kV
Songo
GMPC+
EC f P
PLC SignalTransmission
GPS
BrakingResistorsCahora Bassa
Mozambique
533 kV DC
South Africa
330 kV AC
1500 km
400 kV AC
Matimba Apollo
InterconnectedGrids Signal Processing
for Control andProtection
Bindura
Zimbabwe
PAC
PDC
0
0
1.5
1.5
0
1.5
RTDS
FieldTest
HVDC Current ( kA )
0
1.5
Siemens
Grid Master Power Controller
ESKOM, South Africa
Validation
Analog Graph
x 0.150 0.175 0.200 0.225 0.250 0.275 0.300 0.325 0.350 ... ... ...
-800.000k
-600.000k
-400.000k
-200.000k
0.000
200.000k
400.000k
600.000k
bus
volta
ge
MV1 EA Vas5
-600.000k
-400.000k
-200.000k
0.000
200.000k
400.000k
600.000k
bus
vol
tage
MV1 EB Vcs5
-600.000k
-400.000k
-200.000k
0.000
200.000k
400.000k
600.000k
bus
volta
ge
MV1 EC Vbs5
Advanced Graph Frame
x 0.150 0.175 0.200 0.225 0.250 0.275 0.300 0.325 0.350 ... ... ...
-3.0k
-2.0k
-1.0k
0.0
1.0k
2.0k
3.0k
4.0k
lin
e #
2
DM2 IA Ias4
-2.0k
-1.5k
-1.0k
-0.5k
0.0
0.5k
1.0k
1.5k
lin
e #
2
DM2 IB Ics4
-2.0k
-1.5k
-1.0k
-0.5k
0.0
0.5k
1.0k
1.5k
line #
2
DM2 IC Ibs4
Voltages Currents
Near the fault bus
Fault recordings
Model validation
125
Recent
Developments
RTDS Technologies Inc.
126
Recent Developments
Requirements:
more accurate power system modelling
Resources:
more powerful processors
Led to
Further developments in RTDS real time simulation
Continued development in both hardware and softwareContinued development in both hardware and software
Aimed at meeting changing needs of power system Aimed at meeting changing needs of power system engineers and of the power system itselfengineers and of the power system itself
127
Recent DevelopmentsRecently developed models for GPC card:
Phase Domain Transmission Lines
UMEC Transformer
Voltage Source Converters
128
Simulation:Simulation:
Non Real Time:
• Solution process is not hard real-time, hence interpolation can be used even in large closely connected networks with numerous switches
Real Time:
• Hard real-time required, hence interpolation cannot be applied in large closely connected networks with many switches
• VSC Bridge; Adequate valve firing resolution provided by small time-steps
• Main Network; simulation is more efficient with larger time-steps
• Conflicting requirements
• Multiple timestep approach chosen
Recent Developments
Challenge of VSC modellingChallenge of VSC modelling
The main network ---
Requires a normal time step of approximately 50 μs
The VSC model ---
Requires a firing resolution of a few microseconds
129
Recent DevelopmentsVSC Sub-Network
• Efficient EMT simulation programs often utilize the concept of sub-networks
• Individual sub-networks can be solved in parallel
• Taking this approach we map VSC bridges into individual sub-networks
• The VSC sub-network interfaces with the main circuit
• The interface is similar to well known “hybrid” analogue/digital real-time simulation methods
• VSC interface is fully digital and eliminates difficulties with D/A and A/D conversions as well as amplifiers used in the hybrid simulator
• Small time-step solution in the VSC sub-network is interfaced to large time-step solution of the main network
V
VoltageAmplifier
D/A
A/D
I
CurrentMeasurement
V
RTDSSimulator
Main Network(50 us)
STATCOM
Analog VSC Model(continuous solution)
I
CurrentMeasurement
V
RTDSSimulator
Main Network(50 us)
STATCOMRTDSSimulator
+-
Discrete Time-StepVSC Model
(1.4 to 2.0 us)
130
Recent DevelopmentsExample Simulation Test Case
Small time-step execution time minimized by linking pre-created machine language modules
Doubly fed induction machine with saturation
Six-pulse two-level bridge (two units)
Three-phase high pass filter bank
Three-phase RL branch
Capacitor branch
Three-phase interface transformer
Network solution equations
= 0.4 sec
= 0.22 sec (per unit)
= 0.09 sec
= 0.05 sec
= 0.025 sec
= 0.11 sec
= 0.2 sec
Total small time-step execution time
~ 1.32 sec
Small time-step used in example case
~1.67 sec
131
Recent DevelopmentsExample Simulation Test Case
Validation of real-time results against PSCAD non real-time simulation with 50 sec time-step
RTDS PSCAD
132
Recent DevelopmentsMore Recent Work
Real Time Simulation of 3-level STATCOM with 36 valves
133
RTDS Technologies Inc.
Conclusion
134
ConclusionImpact of Real Time Digital Simulation Techniques:
Real time digital simulation: • represents an important advancement in the understanding of power system
operation and performance
• allows more organizations to establish affordable and manageable in-house simulation facilities
• combines the accuracy of digital models with the real time response of traditional analogue simulators
• provides a mechanism to rigorously study and test the performance of new and existing protection and control devices prior to installation in the actual power system
• provides detailed knowledge of power system performance before, during, and after an event
• increases confidence and reliability in the design, implementation and operation of the electrical network and its complex components
135
Additional Information:
• Our website
www.rtds.com
• Technical publications– Multiple volumes of published papers available dating back to 1991
• Technical documentation and tutorials– Including on-line reference
RTDS Technologies welcomes any questions or comments. Please do not hesitate before, during and after installation to contact us.
RTDS Technologies Inc.
136
Generator ControlsGeneric controls:• Controllers based on PSS/E models
Stabilizers Exciters
EXAC1AVREXAC1AAVREXAC2AVREXAC3AVREXAC4AVREXDC2AVR
EXST1AVREXST1AAVREXST2(A)AVREXST3AVREXPIC1AVR
IEE2STPSSIEEESTPSSPSS2A
Governor / Turbine
GASTGOVHYGOVGOVIEESGOGOVIEEEG1GOVIEEEG2GOVIEEEG3GOVTGOV1GOV
137
Generator ControlsDetailed exciter simulation:• Static exciter with detailed rectifier circuit
138
Generator ControlsDetailed exciter simulation:• Automatic voltage regulator
139
Generator ControlsDetailed exciter simulation:• Protection
Under ExcitationLimiter
Stator Current Limiter
Volts per HertzLimiter
Over ExcitationLimiter