IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Chapter 6: Real-Time Digital Time-Varying Harmonics Modeling and Simulation Techniques Contributors: L-F. Pak, V. Dinavahi, G. Chang, M. Steurer, S. Suryanarayanan, P. Ribeiro Tutorial on Harmonics Modeling and Simulation

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Need for Sophisticated Tools for Power Quality (PQ) Studies  Proliferation of nonlinear and time-varying loads has led to significant power quality concerns.  Traditionally, time-varying harmonics were studies using statistical and probabilistic methods for periodic harmonics.  Cannot describe random characteristics  Cannot capture the reality of physical phenomena.  A time-dependent spectrum is needed to compute the local power-frequency distribution at each instant.  Significant advances in equipment for PQ monitoring, waveform generation, disturbance detection, and mitigation.  Digital signal processing is widely used.  Sophisticated power electronic controllers are used for PQ mitigation.  Need for testing and validation of such equipment.  Real-time digital simulation as an advanced tool for PQ analysis and mitigation.

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Real-Time Harmonic Modeling and Simulation Techniques  Wave Digital Filters  Discrete Wavelet Transform  Real-Time Electromagnetic Transient Network Solution  Real-Time Digital Simulators  RTDS  PC-Cluster Based Simulators  HYPERSIM  DSPACE

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Wave Digital Filters  Digital Signal Processing tool that transforms analog networks into topologically equivalent digital filters  Synthesis is based on wave network characterization  Designed to attain low-sensitivity structures to quantization errors in digital filter coefficients  Powerful technique for simulating power system harmonics and transients

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Discrete Wavelet Transform  Time-Frequency representation of time varying signals.  Wavelet analysis starts by adopting a prototype function. Time Analysis is done with a contracted high-frequency prototype. Frequency analysis is done using a dilated low- frequency prototype.  Operator representation theory is used to model electrical componenets in discrete wavelet domain

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, PC-Cluster Based Real-Time Digital Simulator  Real-Time eXperimental LABoratory (RTX-LAB) at the University of Alberta.

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8,  Fully Flexible and scalable  Fast FPGA based analog and digital I/O and high intra-node communication speed  Varity of synchronization options  Compatible with MATLAB/SIMULINK and other programming languages Features of the RTX-LAB Simulator

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8,  Two types of computers- Targets and Hosts  Targets are dual CPU based 3.0 GHZ Xeon, work as the main simulation engine and facilitates FPGA based I/Os  Hosts are 3.00 GHZ Pentium IV, used for model development, compilation and loading of the model to the cluster Hardware Architecture of the RTX-LAB Simulator

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Software Architecture of the RTX-LAB Simulator  Target OS- RedHawk Linux  Host OS- Windows XP  Model Development- MATLAB/SIMULINK Other programming Languages C, C++

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8,  InfiniBand Link Maximum Throughput- 10Gbps  Shared Memory bus speed – 2.67Gbps  Signal Wire Link Data Transfer rate-1.2Gbps  Gigabit Ethernet link Transfer Rate- Up to 1Gbps  I/O signals from real-hardware are connected through FPGA based I/Os  Xilinx Virtex-II Pro is used 100 MHZ operation speed Communication Links in the RTX-LAB Simulator

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Subsystems and Synchronization in the RTX- LAB Simulator

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 1: Time-Varying Harmonic Analysis on the RTX-LAB Real-Time Digital Simulator Single-line Diagram of the Arc Furnace Installation

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 1: Time-Varying Harmonic Analysis on the RTX-LAB Real-Time Digital Simulator Schematic of the Arc Furnace Model

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 1: Time-Varying Harmonic Analysis on the RTX-LAB Real-Time Digital Simulator Voltage and Current for the Arc Furnace

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 1: Time-Varying Harmonic Analysis on the RTX-LAB Real-Time Digital Simulator Voltage at the Primary Winding of the MV/LV Transformer

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 1: Time-Varying Harmonic Analysis on the RTX-LAB Real-Time Digital Simulator Current in the Primary Winding of the MV/LV Transformer

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Provides time domain solution in real time with typical time step sizes around 50 μs using the Dommel (EMTP) algorithm Features dual time step (<2 μs) capability for PE simulations Allows up to 54 electrical nodes per rack, but subsystems can be connected through cross-rack elements (transmission lines, etc.) Large library of power system and control component models (like EMTDC) > 350 parallel DSPs > 2500 analog outputs and over 200 digital inputs and outputs RPC – Network Solution IRC – Inter-rack Communication WIF – Workstation Interface 3PC – Controls, system dynamics GPC – Network solution, fast-switching converters RTDS at CAPS

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Largest RT simulator installation in any university worldwide Systems of up to 250 three-phase buses Sufficient high-speed I/O to enable realistic HIL and PHIL experiments 14 Rack RTDS Installation at CAPS

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, (Controller) hardware in loop (HIL) and power hardware in loop PHIL Simulated rest of system

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 2: Power Quality Sensitivity Study of a Controller on the RTDS Schematic of the Industrial Distribution System and Rectifier Load

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 2: Power Quality Sensitivity Study of a Controller on the RTDS Single-phase Voltage Sag (40% reduction, no phase shift) and its Impact on Rectifier DC Output

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 2: Power Quality Sensitivity Study of a Controller on the RTDS Phase-Shifted Single-phase Voltage Sag (40% reduction) and its Impact on Rectifier DC Output

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Voltage (kV) Case Study 3: Harmonic Distortion on the RTDS Shipboard Power System

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 4: A HIL Simulation for Studying the Transient Behavior of Wind DG

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Case Study 4: A HIL Simulation for Studying the Transient Behavior of Wind DG

IEEE PES General Meeting, Tampa FL June 24-28, 2007 Conferência Brasileira de Qualidade de Energia Santos, São Paulo, Agosto 5-8, Conclusions  With rising number of time-varying and nonlinear loads sophisticated harmonics modeling and simulation tools are needed.  A combination of fast topological methods and powerful real-time simulators can overcome limitations of off-line simulation tools.  A general review of current off-line harmonic modeling and simulation tools is presented.  Currently available real-time simulation techniques are discussed.  Two real-time case studies: arc furnace modeling and power quality sensitivity of a controller, are presented.