Indirect Vector Control of Linear Induction Motors Using Space Vector Pulse Width Modulation

Vector control schemes have recently been used to drive linear induction motors(LIM)in high-performance applications.This trend promotes the development of precise and efficient control schemes for individual motors.This research aims to present a novel framework for speed and thrust force control of LIM using space vector pulse width modulation(SVPWM)inverters.The framework under consideration is developed in four stages.To begin,MATLAB Simulink was used to develop a detailed mathematical and electromechanical dynamicmodel.The research presents a modified SVPWM inverter control scheme.By tuning the proportional-integral(PI)controller with a transfer function,optimized values for the PI controller are derived.All the subsystems mentioned above are integrated to create a robust simulation of the LIM’s precise speed and thrust force control scheme.The reference speed values were chosen to evaluate the performance of the respective system,and the developed system’s response was verified using various data sets.For the low-speed range,a reference value of 10m/s is used,while a reference value of 100 m/s is used for the high-speed range.The speed output response indicates that themotor reached reference speed in amatter of seconds,as the delay time is between 8 and 10 s.The maximum amplitude of thrust achieved is less than 400N,demonstrating the controller’s capability to control a high-speed LIM with minimal thrust ripple.Due to the controlled speed range,the developed system is highly recommended for low-speed and high-speed and heavy-duty traction applications.

Realization of Space Vector Pulse Width Modulation Method Based on DSP

In order to compensate for the deficiency of Sine Pulse Width Modulation（SPWM）, on the base of analyzing the principle of space w tot pulse width modulation and being compared with SPWM, the method of solving working time of adjacent vector and the method of generate space voltage vector were introduced. The experiment to the inverter which consists of IGBT proves that SVPWM centrol algorithm can reduce harmonic effectively, it is beneficial to enhancing the utilization rate of voltage source inverter direct current power supply.

Research of the Unity Theory Between Three-level Space Vector and Carrier-based PWM Modulation Strategy

两电平空间矢量脉宽调制（space vector pulse widthmodulation,SVPWM）与正弦脉宽调制（sinusoidal pulse widthmodulation,SPWM）存有一定的本质关系,对于三电平,在常见的8段式SVPWM序列中可以证明,SVPWM与SPWM本质上也存在某种统一。实际的SVPWM调制中,由于要考虑中点电压平衡、减少谐波等其它性能问题,一般会利用开关冗余状态得到8段以上的开关调制序列。目前的文献中还未曾有对这些情况进行统一性地验证,因此三电平SVPWM与SPWM的统一理论存在一定的不足。研究发现,可通过严格地理论推导将传统意义上的调制波分解为2个子调制波,再进行SPWM调制,可以得到与SVPWM完全吻合的序列。该文在此方法基础上深入研究了8段以上（10、12、14段）的SVPWM调制序列与SPWM的统一。经过严格地理论推导,成功实现了含任意段数的SVPWM序列与SPWM的统一。仿真结果证明了该理论的正确性。

An Improved Hybrid Space Vector PWM Technique for IM Drives

In this paper, an improved hybrid space vector pulse width modulation (HSVPWM) technique is proposed for IM (induction motor) drives. The basic principle involved in the proposed random pulse width modulation (RPWM) cuddled SVPWM is amalgamating the pre-calculated switching timings for various sections of hexagonal space vector boundary and the random selection of carrier between two triangular signals, in order to disband acoustic switching noise spectrum with improved fundamental component. The arbitrary selection between triangular carriers, which is decided by digital signal states (Low or High) of the linear feedback shift register (LFSR) based pseudo random binary sequence (PRBS) generator. The SVPWM offers a control degree of freedom in terms of positioning of vectors inside every sampling interval and hence it has six possible variants of the voltage vectors arrangements in each sector. The developed HSVPWM is thoroughly analyzed in using the MATLAB? based simulation for all SVPWM variants. From the simulation and experimental results viz. harmonic spectrum, harmonic spread factor (HSF), total harmonic distortion (THD) etc., and the superiority of the proposed scheme such as better utilization of DC bus and the randomization of the harmonic power are evidenced. For the practical implementation, Xilinx XC3S500E FPGA device has been used.

Genetic Algorithm Based 7-Level Step-Up Inverter with Reduced Harmonics and Switching Devices

This paper presents a unique voltage-raising topology for a single-phase seven-level inverter with triple output voltage gain using single input source and two switched capacitors.The output voltage has been boosted up to three times the value of input voltage by configuring the switched capacitors in series and parallel combinations which eliminates the use of additional step-up converters and transformers.The selective harmonic elimination(SHE)approach is used to remove the lower-order harmonics.The optimal switching angles for SHE is determined using the genetic algorithm.These switching angles are com-bined with a level-shifted pulse width modulation(PWM)technique for pulse generation,resulting in reduced total harmonic distortion(THD).A detailed com-parison has been made against other relevant seven-level inverter topologies in terms of the number of switches,drivers,diodes,capacitors,and boosting facil-ities to emphasize the benefits of the proposed model.The proposed topology is simulated using MATLAB/SIMULINK and an experimental prototype has been developed to validate the results.The Digital Signal Processing(DSP)TMS320F2812 board is used to generate the switching pulses for the proposed technique and the experimental results concur with the simulated model outputs.

基于虚拟电压矢量的双三相直线磁通切换永磁电机容错SVPWM策略

高可靠性是电梯驱动系统的首要指标。针对双三相直线磁通切换永磁(dual-three-phase linear flux switching permanent magnet,DTP-LFSPM)电机单相开路故障,提出一种基于虚拟电压矢量的容错空间矢量脉宽调制策略。首先,基于单相开路故障下的五维变换矩阵计算得到故障后的32个空间电压矢量分布。然后,筛选部分空间电压矢量,以z子空间电压幅值为零且每个扇区产生对称的脉宽调制波形为目标,重构得到12个虚拟电压矢量,相邻的2个虚拟电压矢量都由3个基本电压矢量组成,并用于合成参考电压矢量,不仅可以减少单相开路故障容错控制时的电流谐波,而且具有计算简单,易于硬件实现等优点。最后,搭建DTP-LFSPM电机驱动控制系统仿真与实验平台,仿真和实验测试结果证明所提容错策略的正确性和有效性。

T型三电平逆变器中点电位平衡电路及控制

直流母线电压中点电位不平衡是T型三电平逆变器的拓扑结构造成的固有问题。这里从T型三电平逆变器的拓扑结构出发,分析了空间矢量脉宽调制(SVPWM)中大、中和小矢量对中点电位不平衡的影响,针对中点电位不平衡,在电源侧并联一个半桥模块且中点与母线中点串联电感的平衡电路,然后对平衡电路被控对象进行建模与分析,推导出中点电压平衡控制框图,通过对上、下电容进行充放电控制,控制中点电位达到平衡,最后,搭建了T型三电平逆变器实验平台,进行了仿真和实验验证,实验结果验证了所提平衡电路和控制的有效性和可行性。

模块化多电平逆变电路的调制算法研究

针对永磁同步电机传统三电平逆变电路无法满足高压场景的问题,采用空间矢量脉宽调制算法对模块化多电平逆变电路进行调制分析,观察其输出电压波形。然后针对模块化多电平逆变电路各相之间容易出现环流现象,对电容电压平衡控制算法进行简化。在Matlab/Simulink中搭建模型仿真,观察和分析模块化多电平逆变电路的输出电压,实验结果验证了采用空间矢量脉宽调制算法对改善模块化多电平逆变电路的输出特性的有效性和简化后的电容电压平衡控制算法具有稳定性。

抑制级联H 桥变换器共模电压的简化SVPWM 策略

为解决传统空间矢量调制策略难以拓展至高电平数级联H桥多电平变换器,以及抑制级联H桥多电平变换器调制策略实现过程中产生的共模电压的问题,本文提出一种简化空间矢量调制策略。该策略基于α'β'坐标系,通过判断空间矢量所处区域,得出其边界开关状态,再引入修正参数K对边界开关状态进行修正,以此提高策略的快速性并完成共模电压抑制。仿真和实验结果表明该策略实现简单,可以将级联H桥多电平变换器共模电压抑制在最小变化范围内。

高频链矩阵变换器直接功率反步控制策略

针对高频链矩阵变换器(HFLMC)电路前后级耦合导致系统动态性能和鲁棒性降低的问题,提出一种基于直接功率的非线性反步控制策略(BS-DPC)。首先,建立HFLMC非线性数学模型和有功、无功功率动态模型,分析双极性电流空间矢量调制策略;然后,在考虑系统不确定性情况下引入2个解耦控制分量,设计直流输出电流和无功功率反步控制器,实现电池不同工况下输出电流参考值的快速跟踪控制;最后,根据李雅普诺夫稳定性理论证明HFLMC闭环系统全局渐进稳定性,并对比传统PI直接功率控制和BS-DPC策略。仿真和实验结果表明,所提BS-DPC策略控制HFLMC提高了输出电流的动态性能和电网波动及直流滤波电感变化下的鲁棒性,响应时间减少了约78%,网侧THD降低了0.98%。

一种新型三电平变换器中点电压平衡调制策略

在大功率轨道交通装备领域中,三电平变换器因具有众多优点,在实际中得到广泛应用,但是也存在中点电压不平衡这一固有问题。为解决三电平中点箝位(NPC)型变换器存在的中点电压不平衡问题,减少输出相电流畸变情况,提高系统运行稳定性,文章提出了一种基于分析中点电荷量的双自由度新型中点电压平衡调制策略。该调制策略首先从数学分析的角度介绍了三电平变换器直流侧中点电压不平衡问题的原因;之后分析了在空间矢量脉宽调制(SVPWM)技术中,电压矢量输出序列对中点电压的影响;最后基于上述分析结果,改进传统的电压矢量输出序列,并基于改进序列的特点提出了一种新的双自由度中点电压平衡调制策略,通过双自由度的平衡因子调节作用时间。理论上,所提出的新型调制策略具有更多可控电荷量,相较于传统方法具有更良好的控制效果;仿真和试验结果验证了所提的新型调制策略对中点电压的控制效果具有更好的快速性和稳定性。综上所述,文章所提的新型双自由度调制策略可更有效解决三电平变换器存在的中点电压不平衡问题。

改进蛇算法的七电平逆变器SHEPWM研究

多电平逆变器控制策略中的特定谐波消除脉宽调制(SHEPWM)能够以较低的开关频率得到较好的电压输出波形,重点在于开关角的求取。在多电平逆变器SHEPWM调制的开关角求解算法上提出改进蛇优化算法,对传统蛇优化算法采用Tend混沌映射初始种群,使初始种群分布更加均匀;引入Levy飞行策略增强算法的全局搜素能力,能够更加精准快速得到全局开关角的最优解。仿真结果表明,改进蛇优化算法所求的开关角相较于传统算法更好地消除低次谐波,并降低了输出线电压的畸变率,充分验证了该方法的可行性。

Dual-frequency Discontinuous Space Vector Pulse Width Modulation for Five-phase Voltage Source Inverters with Harmonic Injection

This paper proposes a dual-frequency discontinuous space vector pulse width modulation(DFDSVPWM)for a five-phase voltage source inverter with harmonic injection.In this modulation,for dual-frequency voltage output and reduction of switching losses,two different zero-vector-inserted modes are flexibly employed by alternatively using two types of zero vectors.Based on the comparison with continuous SVPWM,the idea and principle of the proposed DFDSVPWM are analyzed and an example of PWM signals for one bridge is also presented.For switching losses analysis,the impact factors and the calculation method are investigated and the corresponding implementation is given as well.The simulation and experimental results from a prototype verify the correctness and effectiveness of the proposed modulation and it has the advantages of outputting dual-frequency voltage and reducing switching losses.

风电机组叶片的无人机除冰控制系统设计与优化

针对内蒙古等北方高寒地区风电机组叶片覆冰问题,提出风电机组叶片的无人机除冰喷射控制系统。基于STM32F103基础,设计无人机除冰控制系统,从除冰剂喷射控制、传感器采集数据实时监测、遥控操作及装置安全控制等功能需求出发,制定系统方案并完成除冰控制系统总体设计,针对试验中流量控制存在的问题对除冰控制系统的PWM驱动控制部分进行软硬件优化,采用离散式PID控制算法,负反馈闭环控制系统提高流量精度和除冰效率。完成除冰控制装置整合及系统调试,搭建实验平台,选择八旋翼无人机载具并进行参数设置及飞行测试,最终完成整个除冰无人机设备整合,实现精准局部除冰。

基于EMD-AVOA-BP的逆变器故障诊断方法

以CRH3C型动车组逆变器中的绝缘栅双极型晶体管(IGBT,Insulated Gate Bipolar Transistor)双管开路故障为研究对象,提出了一种基于非洲秃鹫算法(AVOA,African Vultures Optimization Algorithm)和优化的反向传播(BP,Back Propagation)神经网络的逆变器故障诊断方法。在Simulink中搭建列车逆变器的控制模型,取得故障电流;采用经验模态分解(EMD, Empirical Mode Decomposition)对电流信号进行去噪和故障特征提取,再利用AVOA对BP神经网络进行优化,实现了对列车逆变器IGBT双管开路故障的诊断。与传统方法进行对比可知,该方法具有更高的精准度,在测试集中其精准度达到100%。

单相级联整流器开路故障诊断和容错均压空间矢量脉宽调制算法

针对单相级联H桥整流器(CHBR)的功率开关器件存在的开路故障问题,研究一种开关管开路故障的快速诊断算法,以及针对开关管开路故障的容错均压空间矢量脉宽调制(SVPWM)算法。首先,该文分析单相CHBR功率开关管开路故障时电流流通路径的变化,建立电流误差变化率的分析模型,并提出一种基于电流误差变化率的快速诊断算法。该算法可以快速且准确地定位到故障开关管,且易于在程序中实现。其次,该文提出一种故障容错均压SVPWM算法,该算法在开关管开路故障时利用冗余矢量和冗余开关状态可以使系统在发生故障时仍然可以正常运行,并且各模块间的直流电压也能保持均衡。最后,通过仿真和实验验证了该文所提算法的可行性。

一种PMSM位置伺服系统的动态建模与控制

本文根据永磁同步电机(PMSM)的基本电磁关系及其动态数学模型建立了位置伺服控制模型,按照闭环负反馈控制原理,设计了具有电流、速度、位置三闭环的位置控制系统。首先,根据PMSM矢量控制的特性,利用3S/2S和2S/2R的坐标变换理论,建立了位置伺服系统在同步坐标系下的动态数学模型,同时给出了按照转子磁场定向的位置控制策略和算法;其次,研究了基于空间矢量脉宽调制(SVPWM)的数字实现,并根据电机的数学模型,在MATLAB/Simulink环境中构建了三环模型,同时搭建了基于DSP实验样机。在仿真和实验中直轴、交轴以及速度和位置均采用PI控制,在控制参数的整定过程中,遵循先内环(电流环),后速度环,再位置环的增量调试原理,实现了同步电机的位置闭环控制;最后,对仿真结果和试验结果进行了对比分析,说明了模型的正确性和有效性。

基于dSPACE的新型双滑模PMSM控制方法

设计一种基于滑模理论的永磁同步电机控制系统,利用滑模控制器代替传统的PID控制器,用滑模观测器代替传统的位置传感器。滑模控制器中针对传统滑模控制的抖振问题,引入准滑模和趋近律的概念,设计一种新的滑模控制器。滑模观测器使用连续饱和函数代替传统的开关函数,有效地减少高频噪声信号,经李亚普诺夫稳定方程证明系统的稳定性。本设计方法充分发挥滑模控制的优势。通过d SPACE实验平台的验证和Control Desk环境的实时观测,证明所设计的新的滑模控制器在消除抖振和抗干扰方面明显优于传统的滑模控制器和PID控制器,滑模观测器能准确地观测位置信号,而且针对具有噪声干扰的场合,加入卡尔曼滤波器,有效地减少了干扰信号。

基于单相脉宽调制整流技术的宽范围交流可调电抗器

设计一种宽范围交流可调电抗器,在单相脉宽调制整流技术的基础上,基于二阶广义积分算法构造虚拟正交分量,采用dq电流解耦控制算法进行双环控制,使交流侧电流滞后电压90°,实现可调电抗器的运行方式.仿真结果表明,该可调电抗器具有更宽的感抗调节范围、工作电压范围、工作电流范围和功率范围,有望在交流电领域获得更广泛的应用.

dSPACE电机控制平台设计与SVPWM矢量控制实现

以d SPACE半实物实时仿真系统为基础,利用d SPACE与MATLAB/Simulink可以实现无缝链接的优势,将离线仿真模型通过试验进行快速验证,提高电机控制系统开发效率,缩短项目开发周期。介绍了d SPACE标准组件系统的软硬件环境,完成基于d SPACE电机控制试验平台的设计。最后在此平台上实现永磁同步电机SVPWM矢量控制,验证了d SPACE电机控制试验平台进行控制算法开发的高效性。