电力驱动系统实时控制虚拟实验平台

在研制复杂大功率电力驱动系统的过程中，实际测试前采用虚拟实验平台对控制器的中断延迟、计算速度、内存、接口、通信等瓶颈和瑕疵进行排查，可缩短开发周期，降低开发费用和技术风险。该文依据实际电力驱动系统结构，提出离散事件交流器系统与连续时间电机系统解耦的实时仿真框架，并基于Simulink开发电力驱动系统实时模型库；采用dSPACE实时仿真环境生成模型的实时C代码，基于两定时器任务实现交流驱动系统15～—20μs步长实时仿真。实时仿真系统具有与实际系统的实时硬件接口，可以与实际控制器或实际电机系统直接相连，构成硬件在回路仿真测试或快速控制原型系统。在一般的实验室中可以对大功率电力驱动系统进行测试、教学和操作培训。     

单相感应电动机控制策略综述

文章讨论了目前已应用于单相感应电机调速控制系统的各种逆变器的拓扑结构,分析了最近提出来的几种逆变器拓扑结构,并对其优缺点进行比较.对于单相感应电机来说,在不同拓扑结构的逆变器的各种控制方案中,脉宽调制变频控制是最佳的选择,而变频控制并未广泛地应用于单相感应电机的控制中.开环恒压频比控制由于其适合三相电路,而还没有应用到单相感应电机的控制.对于恒转矩负载,在低速运行时运行频率的变化会引起电机速度变化的不稳定,因此,恒压频比控制仅适用于速度较高时的电机控制,而在低频时系统性能的改善可以通过改变通常的恒压频比控制关系来得到理想的特性.文章对传统的和最近提出的拓扑结构的逆变器的仿真结果进行了分析研究.     

A self-tuning controller for mimo non-linear systems

A new self-tuning control (STC) strategy for non-linear, multi-input/multi-output control problems is proposed. This strategy is applicable to a broad class of non-linear systems, which can include any nonlinear functions of the old inputs and outputs as well as the products of these functions and any powers of the most recent inputs. Simulation results for a two-link robot manipulator demonstrate that the new non-linear STC strategy provides significant improvement over conventional STCs based on linear models.     

On the interharmonic components generated by adjustable speed drives

The interharmonic generation process is addressed with reference to high power adjustable speed drives based on double stage conversion systems using line commutated or pulse width modulated inverters. Reference is made to ideal supply conditions. Formulas to forecast the interharmonic frequencies due to the interaction between the rectifier and the inverter are developed and a proper symbolism is proposed to recognize the interharmonic origins. Comprehensive analyses are performed for both the considered adjustable speed drives in a wide range of output frequencies and with reference to supply system side, output side, and dc link.     

Demand-side management opportunities through the use ofenergy-efficient motor systems

The key issues related to efficient motor systems operation are presented, with a particular emphasis on electronic adjustable speed drives (ASD), due to their comparatively larger potential for savings. The potential for savings associated with the use of ASD in the residential, commercial, and industrial sectors are presented. With ASD it is estimated that one-fifth of the drive power consumption can be saved, that, is over 250 TWh/yr. The combined use of ASD with other efficient motor technologies can increase the savings to 30%. Research, development, demonstration, and training options are proposed which can significantly expand the cost effectiveness, performance, and scope of efficient motor systems applications     

基于MRAS的多相永磁直驱型风力发电系统无速度 传感器控制策略研究

对采用多相永磁同步发电机的大功率直驱型变速恒频风力发电系统进行了研究。系统采用六相永磁同步发电机和多重化的AC-DC-AC变换器,以减少每个电机绕组中的电流和每个电力电子变换器中的电流。研究了一种基于模型参考自适应(Model Reference Adaptive System,MRAS)的六相永磁同步发电机无速度传感器控制策略。该策略将永磁同步发电机本身作为参考模型,将发电机的电流模型作为可调模型,设计了自适应律同时辨识永磁同步发电机的转速和转子位置。还研究了基于变步长爬山法的最大功率跟踪(Maximum Power Point Tracking,MPPT)控制策略,该策略具有动态功率跟踪速度快和稳态时速度平稳的优点。实验结果表明,上述控制策略在负载突变和转速突变时均能准确地检测到发电机的转速和转子位置;在风速变化时能准确地跟踪最大功率。     

基于磁链控制的异步电机V/F控制系统直流预励磁起动方法

结合常规的直流预励磁方法提出了一种适用于变频器-异步电机VVVF控制系统的起动方法,以解决中大容量通用变频调速系统起动电流过大的问题。该方法的本质是电机磁链控制,以直流预励磁建立的磁链为初始状态,然后在起动过程中根据定子电流的无功分量反馈值修正输出电压,维持稳定的圆形旋转磁链。这种方法解决了常规直流预励磁方法有效作用时间短的问题,能提高电流对称性与转矩的稳定性,对整个起动过程中尖峰电流抑制效果明显,且实验效果在380V/315kW异步电机上得到验证。     

区域电网内多输电断面有功协同控制策略在线生成方法

以多个断面功率不越极限为控制目标、调整量最小为优化目标,基于直流潮流法的断面有功灵敏度建立求解多断面有功协同控制策略的非线性规划模型;为提高模型求解的可靠性和速度,引入辅助变量将该模型转化为线性规划模型;利用交流潮流法进行安全校核,以检验策略的有效性。从计算启动、建模求解及安全校核三方面设计闭环的在线滚动计算流程;提出适用于各种网络拓扑变化的节点电纳矩阵及其逆矩阵的滚动修正方法;采用可调元件有功调节限值修正策略剔除无效的调整措施。案例结果验证了所提方法的有效性;且每轮计算耗时在2 min以内,表明所提方法的计算速度满足实时调度要求。     

模块化多电平变流器调速系统变频控制

模块化多电平变流器(MMC)凭借着诸多优势成为高电压大功率工况下的核心拓扑。但MMC变频调速系统运行于低频状态时存在桥臂能量分配不均衡、子模块电容电压波动严重等问题,不仅影响变频器全速域运行能力,甚至威胁系统安全。为解决上述问题,提出一种基于共模电压与偏置电压控制的MMC变频调速系统全速域运行方法,旨在通过控制系统各桥臂瞬时功率以快速抑制子模块电压波动。首先,构建系统数学模型,分析悬浮电容电压波动影响因素;其次,设计变频调速系统的低频控制器与在线模式切换环节;最后,为验证所提控制策略的可行性和有效性,对其进行仿真和实验的对比分析。实验结果表明,所提控制策略能有效抑制MMC变流器子模块电压波动,完成不同频段平滑切换,降低系统损耗,改善系统输出品质,提升MMC系统安全运行能力。     

全功率变速抽水蓄能机组无功优先控制策略研究

全功率变速抽水蓄能机组具有功率快速可调、响应速度快、有功无功独立解耦的优点,可为电网运行提供调峰、调频、无功电压支撑、需求侧响应等多种服务,是现阶段抽水蓄能技术发展的主要技术方向之一。但受变流器过流能力限制,全功率变速抽蓄在任何时候的最大电流不能超过变流器过载能力。而电网侧在故障期间及故障恢复期间对有功、无功的需求有所不同,本文比较了变速抽蓄机组的几种有功、无功电流分配策略,提出了变速抽蓄机组的无功电流优先控制策略可满足弱电网在故障期间对无功电压的需求。最后通过变速抽水蓄能机组在实际电网中的仿真分析,验证了该策略的正确性。     

一种适用于高渗透率主动配电网的电能质量调节器

针对高渗透率主动配电网的电能质量扰动问题,提出一种以可调电抗器为基底,结合有限控制集模型预测控制(FCS-MPC)的新型电能质量治理装置.该装置借助磁链控制原理,向串联型有源滤波器变压器二次侧施加电压改变自身阻抗以对电能质量扰动进行调节,从而达到对电能质量的综合治理.该调节器可以借助自身的结构优势对谐波起隔离作用,结合...     

Fan Control for the Glass Industry Using Static Induction Motor Drives

The glass industry uses large fans requiring high horse- power drives in several glassmaking processes. For example, forming fans are used to manufacture fiber glass insulation and mold cooling fans are employed in the manufacture of glass containers. Substantial electrical energy savings can be achieved using adjustable speed fan control rather than damper control. Other noneconomic benefits also accrue to the user of solid-state drives for these applications.     

Analysis of an adjustable speed rotary condenser for power system stabilization

Over the last five to ten years, significant progress has been made in high‐power semiconductor devices and in their practical applications to power systems. This comes not only from sophisticated semiconductor technology but also from the demand for a higher degree of frequency and voltage stability, and for greater reliability in power systems. This paper deals with an adjustable speed rotary condenser capable of not only reactive power control but also active power control based on a flywheel effect of the rotor. The behavior of a power system consisting of the adjustable speed rotary condenser, a synchronous generator, and a transmission line is subjected to a set of nonlinear differential equations. The set of nonlinear equations can be linearized by limiting attention to small perturbations around a reference state, thus leading to the so‐called Heffron–Phillips model of the power system. The Heffron–Phillips model derived is effective in analyzing effects of the adjustable speed rotary condenser on power system stabilization. The validity of the analysis is confirmed by computer simulation based on EMTDC. Finally, it is discussed how well power system stabilization is achieved by the rotary condenser. As a result, the rotary condenser has the function of decoupling reactive power control from active power control, thus producing a good effect on power system stabilization which would not be achieved by a conventional inverter‐based static var compensator. © 2000 Scripta Technica, Electr Eng Jpn, 133(1): 31–42, 2000     

Hybrid-active filtering of harmonic currents in power systems

Use of nonlinear loads and devices in power systems is expected to grow rapidly. Examples are thyristor-controlled inductors for FACTS, converters for HVDC transmission and large adjustable speed drives. All of these loads inject harmonic currents into the power system. A novel hybrid filter topology and its control, to prevent such harmonic currents from entering the power system, are presented in this paper. Analysis shows that in the proposed filter, the power electronic converter, required to generate harmonic currents for compensation, has a rating of only 9% when compared to the converter rating in an active filter and approximately one-half of that in a series-hybrid filter discussed in the literature. The proposed topology enables practical implementation of active harmonic current filters. The control of this filter under transient conditions such as start-up and during steady state is demonstrated by means of simulations. Results from a scaled-down hardware prototype are presented to verify the simulations     

无刷双馈电机的一种矢量解耦控制

无刷双馈电机(BDFM)调速系统可以大大降低调速装置的容量,在大功率调速系统中有着广阔的应用前景,但由于缺乏有效的控制策略,阻碍了其应用和推广,因此迫切需要新型的控制策略来改善其性能,以扩大其应用范围。在同步参考系的矢量解耦数学模型基础上,利用同步角和转矩的关系,提出了一种简单实用的矢量解耦控制,采用这种控制方法,使BDFM的矢量控制变得与普通感应电机的矢量控制一样简单,能用于调速性能要求较高的调速系统。     

综合配网谐波及三相不平衡评价指标的治理设备优化配置策略

以有源电力滤波器为代表的电能质量治理设备多用于补偿本地负载产生的谐波及不平衡电流。随着配网中非线性负荷的大量接入,本地补偿的配置策略存在成本高、效率低的问题,出现了面向网络电能质量全局综合提升的关键点治理设备配置需求。首先,提出了一种基于层次分析法和模糊隶属度的电能质量数据全局评价方法,作为衡量治理设备配置效果的尺度;其次,以全局配置效果、总装机数量和装机容量为优化目标,以网络各节点谐波含量及不平衡度均满足标准为约束条件,通过多目标粒子群算法确定治理设备最优配置节点及容量的配置策略;最后,通过搭建含有分布式不平衡及谐波负荷的IEEE-18节点仿真模型,验证所提全局评价及设备配置策略对于网络电压谐波及不平衡综合优化的有效性和优越性。     

综合配网谐波及三相不平衡评价指标的治理设备优化配置策略

以有源电力滤波器为代表的电能质量治理设备多用于补偿本地负载产生的谐波及不平衡电流。随着配网中非线性负荷的大量接入,本地补偿的配置策略存在成本高、效率低的问题,出现了面向网络电能质量全局综合提升的关键点治理设备配置需求。首先,提出了一种基于层次分析法和模糊隶属度的电能质量数据全局评价方法,作为衡量治理设备配置效果的尺度;其次,以全局配置效果、总装机数量和装机容量为优化目标,以网络各节点谐波含量及不平衡度均满足标准为约束条件,通过多目标粒子群算法确定治理设备最优配置节点及容量的配置策略;最后,通过搭建含有分布式不平衡及谐波负荷的IEEE-18节点仿真模型,验证所提全局评价及设备配置策略对于网络电压谐波及不平衡综合优化的有效性和优越性。     

Voltage Quality Enhancement with Wavelet-Artificial Intelligence Current Limiting Devices

Due to the increased use of digital computers, PWM adjustable speed drives, andautomated controllers in industries, utilities are faced with rising concerns about the quality of power supplied. This paper, based purely on simulations, focuses on the application of current limiting devices on radial distribution systems to enhance the voltage quality at the distribution buses. The first section of the paper demonstrates the effectiveness of the limiting devices in reducing the dips in voltages and associated phase-angle jumps. Because the current devices need to be introduced to the systems almost instantaneously after the occurrence of a fault, the secondsection introduces a new adaptive fault-sensing scheme for use with these devices. This scheme utilizes wavelet packets analysis as a preliminary feature extractor and a neural network as a pattern classifier. Simulations show that the scheme required no user interference and can be applied to any network configuration.     

无刷直流电机小脑模型网络与PID复合控制

为提高无刷直流电机调速驱动系统的性能,提出了无刷直流电机的小脑模型神经网络与PID复合控制策略。介绍了小脑模型神经网络的原理,给出了复合控制器的结构框图及适于数字控制的算法离散化过程,并对控制系统在转速指令和负载转矩变化时的性能进行了仿真和实验验证。结果表明,所提出的智能控制策略在减小转速超调的同时保证了响应速度,能快速平稳的跟踪给定指令,有效的抑制了负载扰动的影响,动、静态性能均优于PID控制。     

应急微电网中柴储移动电源的协调及均衡控制策略

配电网发生停电事故时,可组建应急微电网来应急供应电力。由于应急微电网存在临时建立、通信条件差、工况多变及电源车频繁插拔等问题,提出了应急微电网中柴储移动电源的协调及均衡控制策略,同时将储能与柴油发电机作为主电源供电。所提控制在一次下垂控制与二次频率及电压恢复控制的基础上加入均衡控制,并基于不同时间尺度解耦。其中,柴油发电机的均衡控制通过反馈频率控制信号来修正稳定运行点,以补偿调速器测量误差实现出力均衡;储能的均衡控制根据荷电状态偏差动态调节下垂斜率,以实现荷电状态的均衡。所提控制策略不依赖于中央控制器,有利于应急供电的迅速开展。最后,仿真验证了控制策略的可行性与有效性。