Real-time digital simulator for power system analysis

To understand a number of power system phenomena and to predict critical conditions in system operation, such as voltage collapse, a real-time simulator able to model the dynamic behavior of large power systems has been needed for a long time. The need for real-time simulations stems from the fact that in many practical situations it is desirable to test new equipment and analyze the dynamic behavior of a large power system using the actual pieces of equipment. A new digital simulator was developed based on a hypercube-type massively parallel computer to achieve this objective. The new simulator features: (1) real-time simulation of a large power system which covers transient stability through long-term behavior with constant accuracy level; (2) user-friendly man-machine interfaces which mimics an actual operating environment and realtime data presentation on a CRT; and (3) high-speed digital/analog conversion interfaces which connect the digital simulator to actual equipment.     

Real-time digital simulator with digital/analog conversioninterface for testing power instruments

The need for real-time simulation stems from the fact that in many practical situations it is desirable to analyze the dynamic behavior of a large power system with advanced equipment that has complex and high-speed performance. Analog simulators are effective, however they impose serious limitations on the size of the system that is being modeled. The authors have studied and developed a real-time digital simulator using a hypercube computer, and realized real-time performance available for the analysis of large power systems. As the second step of the study, they developed a digital/analog conversion interface for testing actual power instruments. The interface exchanges the variables of fundamental frequency domain in the real-time digital simulator, and the variables of exact time domain in the analog equipment connected to the simulator. In this paper, the authors describe the detail of the digital/analog conversion interface of the real-time digital simulator for testing advanced power instruments. Its conversion algorithm, system configuration of the simulator with the interface, and experimental results are also presented     

特高压交直流电网数模混合实时仿真系统

国家电网仿真中心数模混合仿真实验室建立了特高压交直流电网数模混合实时仿真系统,模拟特高压交直流跨区大电网.实时仿真系统选用Linux操作系统,采用Hypersim全数字实时仿真软件,通过信号接口和功率接口实现了全数字仿真程序与一次直流物理仿真装置和二次控制保护装置的互联,基于SGI超级计算机实现了大规模交直流电网的数模...     

Development of a new on-line synchronous generator simulator usingpersonal computer for excitation system studies

A new on-line synchronous generator simulator using a personal computer is presented. It can simulate the dynamic response of generator which is represented by a detailed equivalent circuit model in real time. In addition, it can be directly connected to the actual excitation system through the A/D and D/A converters. With this capability, the simulator can be utilized for the dynamic response studies and the controller parameter tuning of the excitation system. Also, user friendly developed interfaces help the operator learn the simulator operation skill with little learning effort. The developed simulator is tested and verified with an actual excitation system implemented on 5 kW generator     

全数字实时仿真器——HYPERSIM

介绍了加拿大HYDROQUEBEC公司开发的一种功能强大、界面友好、接口方便的全数字实时仿真软件HYPERSIM。这种全数字实时仿真软件是为在线实时应用设计的，也可进行离线仿真，可用于电力系统、电力电子及电机拖动分析。A/D和D/A接口、用户代码模块(UCB)接口以及与商业软件MATLAB和EMTP等接口极大地扩充了程序应用的灵活性。文中通过3机9节点系统的仿真实例说明了程序的性能。     

Real-time digital simulation of power electronics systems with Neutral Point Piloted multilevel inverter using FPGA

Most of actual real time simulation platforms have practically about ten microseconds as minimum calculation time step, mainly due to computation limits such as processing speed, architecture adequacy and modeling complexities. Therefore, simulation of fast switching converters’ instantaneous models requires smaller computing time step. The approach presented in this paper proposes an answer to such limited modeling accuracies and computational bandwidth of the currently available digital simulators.As an example, the authors present a low cost, flexible and high performance FPGA-based real-time digital simulator for a complete complex power system with Neutral Point Piloted (NPP) three-level inverter. The proposed real-time simulator can model accurately and efficiently the complete power system, reducing costs, physical space and avoiding any damage to the actual equipment in the case of any dysfunction of the digital controller prototype. The converter model is computed at a small fixed time step as low as 100 ns. Such a computation time step allows high precision account of the gating signals and thus avoids averaging methods and event compensations. Moreover, a novel high performance model of the NPP three-level inverter has also been proposed for FPGA implementation. The proposed FPGA-based simulator models the environment of the NPP converter: the dc link, the RLE load and the digital controller and gating signals. FPGA-based real time simulation results are presented and compared with offline results obtained using PLECS software. They validate the efficiency and accuracy of the modeling for the proposed high performance FPGA-based real-time simulation approach. This paper also introduces new potential FPGA-based applications such as low cost real time simulator for power systems by developing a library of flexible and portable models for power converters, electrical machines and drives.     

交直流大电网数模混合仿真系统的并行计算效率研究

国家电网仿真中心基于SGI Altix 4700超级计算机及全数字实时仿真软件Hypersim建立了交直流大电网数模混合实时仿真系统,Hypersim应用LDU分解算法求解节点电压方程,对网络进行分网并行计算,分析了影响仿真系统并行计算效率的因素。三华电网仿真结果表明,该仿真系统能够满足大电网实时仿真要求,具有较高的并行计算效率。     

基于FPGA的回波模拟器设计与实现

回波模拟器主要完成对雷达引信机射频信号的延迟和衰减,并传输至接收端.传统的模拟延时和模拟衰减通常采用多路开关控制延迟线的方法实现,由于模拟电路存在温度漂移、器件老化影响、抗干扰性能差等缺点,从而使得输入信号质量下降,线路越长,噪声的积累也就越多.以现场可编程门阵列Vertex-5系列的FPGA为核心,研究了数字化回波模拟器总体设计方案,综合利用了模数转换、数字下变频DDC、数字延迟衰减等技术,实现了雷达引信机射频信号的延迟衰减精确可调,完成了频率、功率信号的实时测量,简化了回波模拟器硬件结构,提高了系统集成度和可靠性.     

A versatile cluster-based real-time digital simulator for power engineering research

This paper presents the development of a unique parallel and distributed real-time digital simulator for power engineering research at the University of Alberta. The simulator is built entirely from commodity-off-the-shelf (COTS) hardware and software components, making it very flexible and scalable. In parallel multi-tasking operations, a combination of real-time Linux operating system and an ultra-fast network forms the backbone for the internal communication between the 16 powerful processors of the Xeon-Cluster. Field programmable gate array (FPGA)-based multi-channel digital and analog I/O ports are interfaced to communicate with the external hardware components. The model development software utilized for power applications is based on the highly customizable industry-standard MATLAB/SIMULINK environment. A detailed case study of the real-time simulation of a three-level 12-pulse vector-controlled ac drive is presented to illustrate the precision capabilities of the simulator. Multiple integration algorithms and multirate computation have been applied for the simulation of the system, with slow (machine) and fast (converter) dynamic components. Real-time simulation of the entire system has been achieved with a maximum computation time of 5.35 /spl mu/s on a step-size of 10 /spl mu/s for the first time. Results obtained from the real-time simulation have been validated with an offline simulation using PSCAD/EMTDC.     

Development of advanced power system analog simulator

The digital simulation method has been utilized to analyze phenomena in power systems. Since different algorithms can be applied, depending on the phenomena to be analyzed, digital simulation allows for high-precision analysis. However, it also has a disadvantage: it produces continuous phenomena which occur in actual systems only fragmentarily. Thus, when discussing important projects at research centers such as IREQ in Canada, an analog simulator issued to continuously analyze the phenomena from the moment the fault occurs until steady state. These analog simulators, however, consist of only a few generator models. They are only effective for analyzing phenomena in small-scale systems and do not allow for analysis of phenomena in large-scale systems over a long period of time. For this reason, the Kansai Electric Power Company (KEPCO) in cooperation with Hitachi, Ltd., and Fuji Electric Co., Ltd., has developed the world's largest power system simulator (APSA: Advanced Power System Analyzer). The simulator will be used to analyze the evolution of accidents in actual systems and to analyze continuous system phenomena over a long period. This paper describes an outline of the simulator.     

电力系统物理与数字联合实时仿真

提出了结合物理模拟与数字仿真实现电力系统联合仿真的技术.以替代定理为基础阐述了联合仿真的理论基础,并提出了联合仿真系统的总体布局.数字仿真接口用A/D转换通道与受控注入电流源实现,物理仿真接口用基于直流耦合的背靠背变流器结构的放大电路实现.最后通过实验验证了该技术的可行性.     

超导储能用级联型大功率换流器控制系统设计

在超导储能系统中换流器与电网相连,使超导储能磁体能够通过换流器与电网进行能量交换,从而实现电网谐波抑制、有功无功补偿等功能.根据超导储能用换流器的特点,结合目前大功率电力电子器件以及电路拓扑的发展趋势,设计了一种结构灵活的换流器控制系统.该控制系统采用数字信号处理器(DSP)与复杂可编程逻辑器件(CPLD)相结合的分离模块式构架设计,在功能上实现了控制系统的算法部分与控制信号产生部分分离、系统的模拟部分与数字部分分离,从而大大提高了控制系统的电气稳定性及系统灵活性.该控制系统还可适用于多种大功率换流设备,因而具有较强的拓展性及通用性.     

数字模拟技术分析及微机通道的设计

Ａ／Ｄ和Ｄ／Ａ技术是计算机实时控制系统中的重要组成部分．外界的模拟量（如电压、电流等），只有经过Ａ／Ｄ转换为数字量计算机才能接受，加工、处理；同时，只有经过Ｄ／Ａ转换才能使计算机控制各类伺服系统（如调压、调温等）以达到实时控制之目的．根据实际系统的要求和Ｄ／Ａ、Ａ／Ｄ芯片建立微机通道，在特定接口的基础上用软件支持这种转换的完成，同时，给出了一种用Ａ／Ｄ，Ｄ／Ａ进行正道变换的实用系统．系统的设计方法对建立各自模拟系统的读者有一定的借鉴和启迪作用．     

Modal reduced dynamic equivalent model for analog type power systemsimulator

Analog type power system simulators are playing important roles in cases where real time dynamic studies are required. Power system reductions are more important in analyses using an analog type simulator than a digital computer due to facilities limitations. This paper describes a modal reduced dynamic equivalent model which was developed for an analog type power system simulator to provide power system reductions. The model is implemented by using a modal analysis approach based on a digital type synchronous generator model. In simulator tests on a 28-machine power system, the model is judged to be useful for representing subsystems to be reduced in an analog type simulator     

模块化多电平变换器模拟仿真技术

为降低实时仿真器的成本,提高仿真性能,提出了一种针对功率变换器的实时模拟仿真方法,该方法具有天然的实时处理开关信号及模拟信号的能力,且其仿真速度与系统规模及复杂性无关。以电子模拟开关和运算放大器为核心,分别模拟实现了功率变换器数学模型中的开关函数和数学运算,并针对模块化多电平变换器(MMC)设计了MMC模拟仿真方法及电路,同时研发了MMC模拟仿真平台。通过仿真和实验验证表明了所提方法的可行性和有效性。     

数模混合实时仿真系统及其在特高压交直流电网研究中的应用

介绍了国家电网仿真中心数模混合式实时仿真系统的结构、仿真试验流程及其在特高压交直流混合电网仿真研究中的应用。该系统包括相应的数字模型、物理模拟装置及接口设备,其中高压直流输电模拟系统模型包含与实际直流输电系统特性相近的仿真装置,且具有与实际直流工程相同的控制保护装置。文章阐述了对原系统的等值化简、确定系统模拟比、建立仿真试验系统模型等多个环节的处理过程及相关原则。以金沙江一期及锦屏送出特高压直流工程实时仿真研究项目为例,给出了数模混合实时仿真系统的试验结果并与离线计算结果进行了比较分析,2者基本一致。仿真系统试验结果可为特高压交直流混合电网的规划提供技术参考。     

高精度线性功率电压源的研制

为满足电能质量分析、仪器校验和产品测试的需要,设计并实现了一种精密的线性功率电压信号源.以MSP430单片机为控制核心,通过直接频率合成技术(DDS)产生需要的正弦波,功率放大部分采用改进型AB类互补对称功放电路,使信号源具有很高的线性度和较大的输出容量.采用16位高精度A/D、D/A转换器并配合模拟乘法器实现闭环反馈...     

An advanced and powerful real-time digital transient networkanalyser

A few years ago, the study and simulation of fast power system phenomena in real-time, was the private ground of analog simulators. But the limitation in modeling, the complexity and the costly maintenance of these simulators was a brake upon their development and made their profitability uncertain. The testing of power system equipment such as controls, relays or power electronic devices needed a new type of simulator, much more versatile and cost-efficient than their predecessors: the real-time digital transient network analysers (DTNA). Until a few months ago, the design of DTNAs was based on dedicated technologies. Today, the ever increasing calculation power has now reached a level that allows real-time simulations of fast phenomena to be carried on standard computers. The authors present in this paper a new and fully digital TNA that relies on a standard computer     

基于RTDS的风光发电系统数字物理混合仿真分析

风光发电系统的仿真分析研究是发展可再生能源发电技术的重要环节,本文针对风光发电系统数字物理混合实时数字仿真的关键技术展开研究,构建风光发电系统电气架构和通信架构,采用实时数字仿真器作为研究工具,建立基于RTDS纯软件的各微电源单体控制系统模型和基于RTDS的数字物理混合仿真单体微电源模型,并分别在稳态和动态两种情况下对其进行仿真分析,研究两者间特性的差异,证明所建模型的有效性,为两类模型的选择使用提供指导。数字物理混和仿真分析条件更接近于实际情况,既可在物理平台上对控制策略的性能进行检验和调试,又可实时修正控制参数、控制策略,为实际工程设计提供重要实践依据。     

基于RTDS的风电场SVC控制器性能检测分析

风电场静止无功补偿器（SVC）控制器的性能对于大规模风电汇集地区电网的电压质量以及系统运行可靠性有着至关重要的影响。为此,在实时数字仿真器（RTDS）中建立了风电场及晶闸管控制电抗器（TCR）型SVC的实时数字仿真模型,即构成一个闭环测试系统,并对实际SVC控制器装置开展性能测试。测试结果表明：这种基于RTDS的SVC控制器闭环性能检测系统能够较全面地测试SVC控制器的动态特性。测试中发现,部分厂家SVC控制器在信号测量、调节器模型设计、网源协调辅助控制功能和控制切换等多方面仍存在亟待完善和改进的问题。