RT-LAB實時仿真技術(shù)

1、Proceedings of the Third International Conference on Modeling, Simulation and Applied OptimizationSharjah,U.A.E January 20-22 2009REAL-TIME PLATFORM FOR THE CONTROL PROTOTYPING ANDSIMULATION OF POWER ELECTRONICS AND MOTOR DRIVESSimon Abourida, Jean BelangerOpal-RT Technologies Inc.1751 Richardson #2

2、525Montreal, J4P 1G6, Quebec, CanadaSimon.abouridaopal-ICMSAO' 09-1Proceedings of the Third International Conference on Modeling, Simulation and Applied OptimizationSharjah,U.A.E January 20-22 2009ICMSAO' 09-#Proceedings of the Third International Conference on Modeling, Simulation and Appli

3、ed OptimizationSharjah,U.A.E January 20-22 2009ABSTRACTThe paper presents state-of-the-art technologies and platform for real-time simulation and control of motor drives, power converters and power systems.Through its support for Model-Based Design method with Simulink?, its powerful hardware (multi

4、-core processors and FPGAs), and its specialized model libraries and solvers, this realtime simulator (RT-LAB?) enables the engineer and researcher to efficiently implement advanced control strategies on embedded hardware, or to conduct extensive testing of complex power electronics and real-time tr

5、ansient simulation of large power systems.1. INTRODUCTIONOver the years, it has been increasingly acknowledged how important and essential the tools of real-time simulation and testing in all industries are. These tools are no longer a luxury in modern system design, especially in electric motor dri

6、ves and power electronics, whose applications are found in an ever increasing number in all sectors. As for power systems, it was the sector that pioneered the use of real-time simulators tens of years ago, starting with analog simulator, before the advent of computers and the development of hybrid

7、then fully digital realtime simulators.On other hand, commercial simulation packages such as MATLAB/Simulink? are now widely used in the industry, education, and research institutions alike. They have become the modeling tools of choice because the many advantages they offer: increase in engineering

8、 productivity and efficiency, and accelerated design cycle by relying on the Model Based Design (MBD) methodology, making it possible to go from concept to simulation without ever having to write code, and producing a working prototype very early in the design process.Because of its advantages, the

9、MBD approach has renewed the importance and interest in real-time simulation and its many applications and spread the usage of RT simulation to new fields, because it had greatly facilitated the development of real-time applications and accelerated their design.Before and after the establishment of

10、this MBD process, several real-simulation time tools has been developed, in different sectors: electromechanical systems, aerospace, power systems, electric drives, railway systems, etcMany such tools were proprietary systems or mere research projects that failed to get into maturity. The few others

11、 that made it to maturity and had many applications and users have restrained their applications solely to the real-time simulation of the complex electric power systems (RTDS, Hypersim1)resulting in high cost for simpler systems like electric drives and industrial power converters; others failed, d

12、espite their success in small applications or complex but slow dynamic systems, to address the needs and requirements of real-time simulation of the fast electromagnetic transients of power systems, and the fast dynamics of today 's power converters and electric motor drives, and therefore, thei

13、r applications stayed confined to systems with relatively slow dynamics (mechanical, hydraulic, aerodynamic systems, etc).A powerful platform for real-time simulation and control of electromechanical and power systems alike that is based on the MBD approach has been developed (RT-LAB) in the mid nin

14、eties, pioneering the use of commercial PC processor as the base platform and using Simulink as the visual design environment. In addition to its scalable, distributed processing hardware, RT-LAB integrates on the software level many solvers and model libraries that were designed to solve the proble

15、ms and challenges of the real-time control and simulation of fast dynamics like those found in electric motor drives, power converters, power grid, renewable energy systems, and other applications.The present paper describes this real-time platform and its architecture, and presents some of its typi

16、cal applications. It is organized as follows: first an introduction to the methodology of model-based design and its applications is given in section 2; then the RT-LAB platform, its hardware architecture and its software are presented thoroughly in section 3, and some application- driven real-time

17、simulators are presented in section 4; typical applications are shown and discussed in section 5, before concluding.2. MODEL-BASED DESIGN AND REAL-TIMESIMULATIONIn traditional design and test methods of control systems, the actual product or even its prototype become available very late in the desig

18、n process; and it is only then, as system integration is done toward the end of the design that the designers were able tofind out if the system work well and behave as it was intended to, or to uncover eventual errors in the design, implementation or integration of the system and its components.Mod

19、el-Based Design process (illustrated on Figure 1) addresses these shortcomings of the traditional development method; it consists of building a mathematical model of the system in a graphical block-diagram environment (like Simulink ?). The entire system model can then be simulated to accurately pre

20、dict, validate and optimize its performance, and to iteratively refine it until it meets the requirements; this is the model design stage.Mcdeloesign4 Black Diagram)GenerateSoftware fromModelUpload Scrftware to RT PlatformFigure 1: The process of Model Based DesignThis system model becomes then a sp

21、ecification from which realtime software code is automatically generated for prototyping and implementation, thus avoiding hand coding and reducing the potential for errors ( automatic software generation).The software automatically generated from the system-level, graphical block diagram is then up

22、loaded to a real-time platform, and is ready for testing. In fact, verification and validation are conducted throughout the development of the product by integrating tests into the models at any stage. This continuous verification and simulation helps identify errors early, when they are easier and

23、less expensive to fix.This model based design process is more and more used in the development of dynamic systems including motor drives and power electronics systems. In educational institutions, this process is becoming the preferred approach for both research and teaching, because it enables the

24、researchers, engineers and students to focus on their design, algorithms, system topologies and different innovative ideas, rather than dedicating a significant part of their effort and time to the intricacies of writing the realtime code and implementing the software on the real-time platform (micr

25、ocontroller, DSP, FPGA, etc).3. RT-LAB REAL-TIME PLATFORMRT-LAB is a powerful, modular, distributed, real-time platform that lets the engineer and researcher to quickly implement block diagram Simulink models on PC platform, supporting thus the model-based design method by the use of rapid prototypi

26、ng and hardware-in-the-loop simulation of complex dynamic systems.The major elements integrated in this real-time platform are: distributed processing architecture; powerful processors, high precision and very fast input/output interface, hard real-time scheduler, and modeling libraries and solvers

27、specifically designed for the highly non-linear motor drives, power electronics, and power systems.3.1. Architecture of RT-LAB platformThe general architecture of RT-LAB is shown on Figure 2. In this host-target architecture, the host is used to develop the model at the design stage, and during runt

28、ime, as the user interface, communicating with the target by Ethernet. The target where the real-time computation done, is a PC and has therefore the standard architecture of a PC; one or two processors are dedicated to the simulation of the Simulink model; a PCI (or PCI-Express) bus connects the pr

29、ocessors to the rest of the system, and to inputs/outputs (I/O) through an FPGA board; the I/O's aremodular and their number can be configured according to the application needs.Host FCPhy&icel Devinconnected to RT-LAB reai-time pSatformFigure 2: The architecture of RT-LAB based simulatorIn

30、addition, several targets can be interconnected with FireWire or PCI Express real-time communication links and switches, making the complete system a super-computer of high computational capacity, ideal for the real-time simulation of complex systems (power grids, wind farms, distributed generation

31、systems in large ships, and others)3.1.1. ProcessorRT-LAB uses Intel? or AMD? processors as real-time targets; there can be a single or two processors in one target; each processor can be single, dual or quad core, so that a single target box can hold as much as 8 processing cores, communicating by

32、shared memory; and each core simulates a Simulink subsystem; this makes such an RT-LAB target box a very powerful distributed processing simulator that can handle very complex simulation applications.In addition, for applications requiring very small simulation step in the microsecond range, RT-LAB

33、uses Xilinx FPGA as realtime target; and while this target requires some extra handling in the model by the designer, the design itself is done equally in the form of block diagram in the same Simulink graphical environment by using the Xilinx Blockset, and the VHDL code is then automatically genera

34、ted from the block diagram, compiled and uploaded to the FPGA; the engineer can then design extremely fast control algorithms or model extremely fast sampling plant models and target them to FPGA without hand coding and without the need of programmable logic chip expertise.3.1.2. Inputs and OutputsI

35、n order to connect the real-time system with real world hardware devices, (controller or physical plant), input/output (I/O) interface is configured through custom blocks, supplied with RT-LAB as a Simulink toolbox (analog, digital, PWM, encoder, serial communication, etc). The engineer drags and dr

36、ops the I/O blocks to the graphic model, without worrying about low-level driver programming. RT-LAB manages the automatic code generation so to direct the model ' s data flow onto the physical I/O cards.RT-LAB platform supports several commercial PCI I/boards; in addition, in order to meet the

37、stringent I/O speed and accuracy requirements of power electronics and drives, it uses digital I/O boards controlled by a 100 MHz FPGA chip yielding a PWM and encoder resolution of± 10 ns, and 16-bits simultaneous fastanalog-digital converters.3.1.3. Software and Modeling LibrariesRT-LAB runs e

38、ither on QNX or RT-Linux real-time operating system; at the heart of the software, there is a hard real-time scheduler that ensures a strict real-time execution of the system code.RT-LAB software automatically handles the real-time communication between processing cores, and processors on different

39、target boxes, as well as the communication with the host station, and it handles the interface between the model code (user actual simulated application) and the I/O devices.On the top of the real-time software, modeling toolboxes and solvers for Simulink has been developed to handle the intricate s

40、imulation needs of fast transients found in switching power converters, electromagnetic transients in power grids, and to interface with commercial blocksets designed by third parties addressing special needs for the simulation of motor drives and other electrical related systems. The table given be

41、low lists the most important of these toolboxes.Table 1: Model and Solver Libraries for RT-LABModuleDescriptionRT-EventsSimulink Blockset of control blocks with real-time interpolation for power electronics & hybrid systems (dynamic systems with events).RTeDRIVESimulink Blockset of converter and

42、 motor models to simulate motor drives in real-time; it includes voltage-source power converters with real-time interpolation techniques.ARTEMISSimulink solver toolbox to simulate line- or load- commutated drives and AC circuits; it is used to run SimPowerSystems models in real-time.RTeGRIDBundle of

43、 ARTEMIS and other models and functionalities optimized for the simulation of power systemsRTeGRIDproBundle of S/W tools to simulate large power grids with power electronic systems; it includes RTeGRID, RTeDRIVE and RT-EventsRT-LAB.XSGDevelopment and run-time tools to design models with Xilinx Block

44、set and run them on Xilinx FPGAXSGeDRIVESimulink blockset designed with Xilinx blocks to simulate power electronic drives on FPGART-LAB.JMAGInterface of RT-LAB to JMAG-RT finite element suite from the Japanese Research Institute Solutions, to run high fidelity motor model on CPU targetRT-LAB.JMAG-FP

45、GAJMAG-RT implemented on FPGA target (1 us)3.2. RT-LAB Based Real-Time Simulators3.2.1. eDRIVEsimeDRIVEsim is an advanced real-time, hardware-in-the-loop (HIL) simulator and control prototyping platform that integrates different libraries in the RT-LAB platform; it is intended for designing advanced

46、 control systems or for performing HIL testing of controllers used in high-speed electric motors, power electronics, and other electromechanical systems.Blocks from specialized modeling libraries like RTeDrive?, RT- Events? and ARTEMIS (with SimPowerSystems?) blocksets can be included by the enginee

47、r in the Simulink model to run on the processor target.In addition, eDRIVEsim lets the user incorporate subsystems designed with blocks from the Xilinx Blockset for Simulink into the model. This allows that part of the model to be executed on the eDRIVEsim FPGA allowing testing of fast controllers a

48、nd protection systems, and achieving a low level of latency unprecedented in the simulation of high speed motors and high switching frequency converters.This is illustrated in Figure 3. In this test, a 3-phase AC motor drive is emulated on the FPGA (with Xilinx blockset for Simulink), and the PWM ga

49、te signals of the simulated inverter comes from an external controller. The graph shows the total delay (latency) from the PWM input sent to the FPGA-based simulator to the currents that come out on the digital-to-analog outputs. The test shows a total latency in the order of 1.5 demonstrates the ve

50、ry high simulation speed of the motor drive emulated on the FPGA.PWhlinpifCuirentcutputAb?ir l.Suscc3+HL 1i JM 25C”sCH3 10JJV OH 1Q0V11-JUL-05Figure 3: Very small latency & time step with the FPGA real-time target of RT-LAB simulator3.2.2. eMEGAsimTo answer the real-time electromagnetic simulati

51、on needs of power systems, the real-time digital simulator eMEGAsim? was also developed on the RT-LAB platform.In eMEGAsim, the user develops controller models withSimulink and electrical circuit models with SimPowerSystem 2. SimPowerSystem is a Simulink toolbox which provides multiple integrated mo

52、dels, all based on electromechanical and electromagnetic equations, for the simulation of power grids and machine drives. ARTEMIS enables SimPowerSystems models to be implemented and run in real-time. With the combination of other Simulink mathematical and physical-domain toolboxes, it is possible t

53、o easily model any power system components interconnected with complex mechanical subsystems and associated controls.An EMTP-RV? 3 interface is also available to facilitate circuit diagram capture and validation of large circuits. The resulting model can be simulated offline using variable-step or f

54、ixed step solvers in Simulink and with ARTEMIS third- and fifth-order fixed-step solver, optimized for real-time parallel simulation of models made with SimPowerSystems.With the integration of the above tools, eMEGAsim becomes a powerful real-time digital simulator for the study of FACTS4 5, in-land

55、 and electric ship power grid, wind farm interconnection with the power grid 6, etc.4. RT-LAB APPLICATIONSRT-LAB is used in various projects in industries and institutions, spread among different types of applications.Depending on the part of the system that is simulated (controller or plant), the a

56、pplications of real-time simulation and of RT-LAB real-time system can be grouped in three major categories. These are explained briefly in the following sections.4.1. Full Real-Time SimulationA control system, is usually made of a controller and a plant connected in closed loop by the means of sens

57、ors sending feedback signals from the plant to the controller and actuators to level the signals sent from the controller to the plant (to power switches, breakers, etc).Full real-time simulation consists of converting the Simulink model of the complete system (plant and controller) to real-time sof

58、tware that is uploaded to RT-LAB real-time platform (simulator) to conduct fully digital real-time simulation of the complete system.As an example, the paper in 57 describes the use of RT-LAB for the real-time simulation of an induction motor drive with field-oriented speed controller, where 8 prese

59、nts the use of RT- LAB PC-cluster simulator for real-time simulation of an All Electric Ship integrated power system analysis and optimization. The project described in 9 explains the hardware and software details of RT-LAB real-time digital simulator and its use for power engineering research. It describes its application for