Real Time Digital Simulation RTDS® Power Systems Simulation in Real Time

RTDS Technologies Inc. Company: Based in Winnipeg, Canada Established in 1994 - 40 °C

RTDS Technologies Inc. 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. 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. RTDS Simulator Users: Electrical power utilities Electrical equipment manufacturers Research and learning institutions 19 countries: North America: Canada(5) , USA(6) Asia: China(20), Japan(11), South Korea(10), Malaysia(1), Singapore(1) Europe: England (4), Finland(1), Germany(1), Greece(1), Italy(1), Netherlands(1), Spain(1), Sweden(1) Other: Brazil (1) , South Africa(1), India(1), New Zealand(1) =69 clients Counting alstom as 2 Counting hitachi kokbu & research as 1 Counting kepco & kepsac as 1 Counting beckwith as 1 – not an installation

RTDS Technologies Inc. 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

Time scales of power system phenomena Presentation title April-19-17 Time scales of power system phenomena Electromagnetic transient modeling and simulation HVDC, FACTS, etc. Generator control Protection Prime mover control LFC Operator actions Frequency variations Lightning Switching Subsynchronous resonance Transient stability Long term dynamics Tie-line regulation Daily load variation Short-duration variations Long-duration variations Impulsive transients Oscillatory transients Voltage fluctuations Imbalance, harmonics, inter-harmonics, notching, noise 10-7 10-5 10-3 10-1 101 103 105 Timescale (seconds) 1 cycle 1 sec 1 min 1 hr 1 day Location

RTDS Technologies Inc. Simulation Techniques:

Transients and Steady State Transient solution Harmonics Non-linear effects Frequency dependent effects Steady state solution RMS Value

Transients and Steady State High frequency Damped (short duration)

Transients and Steady State Transient stability problem Fault / clearance Slow Transients (electro-mechanical)

Electromagnetic transients 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 Open

Basic R-L-C networks Oscillatory transients: Both L and C involved Damping is due to resistance System losses Loads

Transient vs. Steady State Presentation title April-19-17 Transient vs. Steady State Load Flow / Transient Stability Each solution based on phasor calculations Electro-Magnetic Transients Direct time domain solution of Differential Equations Location

Time Step Period of natural frequency is about 1.5 ms 2

Time Step Time step of 1.0 ms 2

Time Step Time step of 5 micro-seconds 2

Time Step Time step of 70 micro-seconds 2

Non Real Time vs. Real Time 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

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;

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

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

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;

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.

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

RTDS Simulation Hardware

Simulation Hardware Custom parallel processing computer 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 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 Parallel Processing – Sharing the burden of calculation: Processor IRC  > t Rack 1 Rack 2 Backplane WIF Computer LAN

Simulation Hardware 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 Modular Hardware: Easy expansion Maximum availability Easy maintenance Full Compatibility Processing power GPC

Simulation Hardware Customer 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

Simulation Hardware RISC 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)

Simulation Hardware 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 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 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 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 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 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 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 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 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

开关量输出回路 装置开关输出回路接线图

Simulation Hardware 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 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 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 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.)

RTDS Technologies Inc. RTDS Simulation Software

Simulation Software RTDS Software: Graphical User Interface RSCAD Power and Control System Software Component Model Libraries & Compiler

Simulation Software RSCAD Graphical User Interface: FILEMAN TLINE RUNTIME DRAFT CABLE MULTIPLOT

Simulation Software 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 Circuit Construction in RSCAD / DRAFT: Circuit assembly Data entry 3 phase drawing models single line drawing mode

Simulation Software Component Editing:

Simulation Software 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 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 Comprehensive library of component models available: Power System Control System Component Model Library Component Model Library

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``

jX`` 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. jX E`` jX`` R Machine jx Trans. Line Infinite BB Relay

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` Tm Inertia, J 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 Ignores leakage flux Assumes flux is confined in the core Neglects Magnetizing Currents Assumes no core reluctance

Simple Transformer

Ideal Transformer Equations

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 Model Rp Lp Rs Ls Lm n:1 Ideal Transformer

Transformer V-I Curve Characteristic Non-Linear region V-I curve knee point Saturation voltage Operating point for voltage transformers Voltage Linear region Operating point for current transformers Current More in Section 10

Non-linear Element Represented as Piece-Wise Linear -i Function  ( t ) ( t - t) slope kn i L iL(t-  t) iL(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 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

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 Takes into account 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 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 Relay Input Sources

np CT load (burden) ns ip is

Burden Magnetizing Branch ip Rp Lp Ls Rs is Ideal CT

ip’ Rp Lp Ls Rs is Es im imr imx Lm Rm Rl

ip’ is Es im Lm Rb Current source

CT Saturation for Symmetric Fault Currents 10 100 1000 CT ratio error [%] 600/5 A, C100 CT with 1.5 W total load resistance Ideal CT CT Primary Current [A] (referred to the secondary) CT Secondary Current [A] CT Saturation for Symmetric Fault Currents 0.1 1 Exciting Current [A] Voltage [V] 15 23 35 48 7

Lm is nonlinear inductor, specified in piecewise linear form -I data points are not readily available ATP provides a routine SATURATION to convert Vrms-Irms characteristics into -I set

Coupling Capacitor Voltage Transformers 9.2 Digital Models of Coupling Capacitor Voltage Transformers CCVT

A CCVT Circuit Connection

A 138 kV CCVT Design HV 138kV C ps C 1 L d1 R R L d1 L C C p R p L s R x 1 C G 2 2 G 3 C C p C L T x s F F L R r 2 d1 G R Z 1 C a Cp b F SW1 R R a d1 x 3 y 1 5kV/115V/66.4V y 2 R h y 3

Voltage Transformer Digital Models

n:1 Ideal Transformer Ls Rp Lp Cp Rm Lm Rs

Simulation Software Component Builder:

RTDS Technologies Inc. Applications

Applications Closed-loop testing of protection systems:

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

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

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

Applications Closed-loop testing of protection systems: Standard electrical connection

Applications Closed-loop testing of protection systems: Interconnection via IEC 61850 GOOSE and Sampled Values

Applications 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 Voltage and Current Signals (low level) Amplified Voltages and Currents (Sec. Levels) Trip and Reclose Signals RTDS Simulator Voltage and Current Amplifiers Protective Relay(s) Interfacing to Protective Relays

Applications 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 Closed-loop testing of control systems:

Applications Testing of Excitation Controllers:

Interfacing to HVDC Controls Applications 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 Digital and Analogue Signals From RTDS to Controls commutating bus voltages dc current & voltage winding currents -breaker status Digital and Analogue Signals From Controls to RTDS firing pulses block/bypass signals control variable monitoring Interfacing to HVDC Controls

Applications 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 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 General Power System Studies & Education: 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

Applications 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

RTDS Technologies Inc. Validation

Validation Validation: In-house Independent validation by customers Commercial studies Industry benchmark cases Electromagnetic Transient Electromechanical Transient Transient Stability Load Flow / Steady State

Validation 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

Grid Master Power Controller Validation Commercial Studies: Siemens Grid Master Power Controller ESKOM, South Africa

Model validation Fault recordings Near the fault bus Voltages Currents

RTDS Technologies Inc. Recent Developments

Recent Developments Requirements: Resources: Continued development in both hardware and software Aimed at meeting changing needs of power system engineers and of the power system itself Requirements: more accurate power system modelling Resources: more powerful processors Led to Further developments in RTDS real time simulation

Recent Developments Recently developed models for GPC card: Phase Domain Transmission Lines UMEC Transformer Voltage Source Converters

Recent Developments Simulation: Challenge of VSC modelling 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 Challenge 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

Recent Developments VSC 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

Recent Developments Example 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 msec = 0.22 msec (per unit) = 0.09 msec = 0.05 msec = 0.025 msec = 0.11 msec = 0.2 msec Total small time-step execution time ~ 1.32 msec Small time-step used in example case ~1.67 msec

Recent Developments Example Simulation Test Case Validation of real-time results against PSCAD non real-time simulation with 50 msec time-step RTDS PSCAD

Recent Developments More Recent Work Real Time Simulation of 3-level STATCOM with 36 valves

RTDS Technologies Inc. Conclusion

Conclusion Impact of Real Time Digital Simulation Techniques: 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

RTDS Technologies welcomes any questions or comments. RTDS Technologies Inc. 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.

Generator Controls Generic controls: Controllers based on PSS/E models Stabilizers Exciters EXAC1AVR EXAC1AAVR EXAC2AVR EXAC3AVR EXAC4AVR EXDC2AVR EXST1AVR EXST1AAVR EXST2(A)AVR EXST3AVR EXPIC1AVR IEE2STPSS IEEESTPSS PSS2A Governor / Turbine GASTGOV HYGOVGOV IEESGOGOV IEEEG1GOV IEEEG2GOV IEEEG3GOV TGOV1GOV

Generator Controls Detailed exciter simulation: Static exciter with detailed rectifier circuit

Generator Controls Detailed exciter simulation: Automatic voltage regulator

Generator Controls Detailed exciter simulation: Protection Under Excitation Limiter Stator Current Limiter Volts per Hertz Limiter Over Excitation Limiter