FPGA-based implementation of online selective harmonic elimination PWM for voltage source inverter

This paper presents a field programmable gate array (FPGA)-based real-time selective harmonic elimination pulse width modulation (SHE-PWM) scheme for voltage source inverter (VSI). The proposed algorithm can generate the switching angles in real time through the approximation of the angles trajectories by simple variable coefficients-based polynomial equations. The proposed algorithm is first presented, analysed, and then its accuracy is checked through angle error analysis. Afterwards, an FPGA-based implementation is used and an induction motor drive is experimentally tested to validate the simulation results. Experimental results showed a good agreement with simulation and proved the validity as well as precision of the proposed algorithm. All intended selected harmonics are eliminated and simultaneously the fundamental is controlled. The output voltage and current present an excellent frequency spectrum with low harmonic distortion and power loss values.     

Analysis of a novel (LCR)trap-LC-RC filter with improved performance for standalone inverters

ABSTRACT

This work introduces a new passive filter structure for a pulse width modulated inverter used in standalone applications. The proposed structure consists of an additional capacitor connected across the resistance-capacitance branch of the traditional LCR filter and an additional resistor connected across the trap filter capacitor in the traditional (LC)_trap-LCR filter configuration which helps to reduce damping power loss and increase harmonic attenuation while maintaining the same overall filter size of conventional filters. A comprehensive parameter design procedure of the proposed filter is introduced which considers inverter switching frequency and choice of damping components. Further, particle swarm optimisation algorithm is newly employed in this work to minimise resonant peaking on the premise of allowable values of overall filter inductance, capacitance and resistance. Simulation and experimental results are presented to analyse the performance of the proposed filter and a comparison is established with other passive filter topologies. A five-level inverter with the proposed filter is implemented using a SPARTAN- 6 XC6SLX25 processor on an experimental set-up. The experimental results show an attractive performance of the proposed filter in providing improved inverter output waveforms, significant harmonic reduction in the high-frequency band, reduced resonant peaking, lesser harmonic distortion and lower damping power loss.     

SPWM与SVPWM在PMSM控制系统中的比较研究

介绍了PMSM（永磁同步电动机）控制原理,SPWM（正弦脉宽调制）和SVPWM（空间矢量脉宽调制）算法,并建立了基于这两种算法的永磁同步电动机控制系统仿真模型,且对模型运行结果进行了FFT分析。分析结果表明：采用SVPWM算法控制永磁同步电动机定子绕组电流总谐波失真,远远小于采用SPWM建立的模型,在永磁同步电动机数字控制系统中SVPWM是更理想的选择。     

矩阵变换器空间矢量脉宽调制控制算法及仿真研究

本文选择最有代表性的三相输入、三相输出交一交矩阵变换器为研究对象,在分析三相-三相矩阵变换器数学模型的基础上,给出了基于常用空间矢量脉宽调制策略的矩阵变换器调制模型和调制策略,并用Matlab Simulink建立了空间矢量调制的矩阵变换器的仿真模型,给出了仿真实验结果。实验结果证实了所提出的空间矢量脉宽调制控制算法的正确性和可实现性。     

Multi-scale spatial convolution algorithm for lane line detection and lane offset estimation in complex road conditions

Deep learning has made remarkable progress in the field of image classification and object detection. Nevertheless, in the autonomous driving research, the real-time lane line detection and lane offset estimation in complex traffic scenes have always been challenging and difficult tasks. Traditional detection methods need manual adjustment of parameters, they face many problems and difficulties and are still highly susceptible to interference caused by obstructing objects, illumination changes, and pavement wear. It is still challenging to design a robust lane detection and lane offset estimation algorithm. In this paper, we propose a convolutional neural network for lane offset estimation and lane line detection in a complex road environment, which transforms the problems of lane line detection into the instance’s segmentation. In response to a change in the method of lane processing, the network will form its example to each line. The global scale perception optimization mechanism is designed to solve the issue, especially where the lane line width is gradually narrowing at the vanishing point of the lane. At the same time, to realize multi-tasking processing and improve performance, and end-to-end lane offset estimation network is used in addition to the lane line detection network.     

基于NSST和自适应PCNN的图像融合算法

针对红外和可见光图像的特点,本文提出了一种基于非下采样剪切波变换(NSST)和自适应的脉冲耦合神经网络(PCNN)相结合的红外与可见光图像融合的新算法。对经过NSST变换后的低频子带系数采用带高斯权重分布矩阵的局域方差和方差匹配度相结合的融合规则,对高频子带系数采用一种改进的空间频率作为PCNN输入,且采用改进的拉普拉斯能量和作为PCNN的链接强度,利用PCNN全局耦合性和脉冲同步性选择高频子带系数,最后经NSST逆变换后得到融合结果。实验结果表明,本文提出的算法与传统的图像融合算法相比不仅在主观视觉上取得较好的效果,而且在客观标准上也有了一定的提高。     

基于RDU-PCNN和NSST的红外和可见图像融合算法

针对可见光和红外图像的融合容易出现块状噪声 、边缘有振铃现象等不足,提出了一种基于区 域双通道脉冲耦合神经网络(RDU-PCNN)和非下采样剪切波变换(NSST)的红外和见光图像融 合算法。首先 对待融合的可见光和红外图像进行NSST分解得到低频系数和高频方向系数,低频系数采用R DU-PCNN的 规则融合,高频方向系数采用离散余弦变换(DCT)的融合规则,对融合后的系数进行逆NSST ,从而得到融合后 的图像。仿真结果表明,与其他5种目前流行或者较为先进的算法相比,本文的算法在视觉 和客观评价指标上优于其他算法。     

Modified ESPRIT (M-ESPRIT) algorithm for time delay estimation in both any noise and any radar pulse context by a GPR radar

This paper presents M-ESPRIT, a modified version of the ESPRIT algorithm, for the purpose of time delay estimation of backscattered radar signals. The proposed algorithm takes both the transmitted pulse shape and any noise into account. It can process raw data from experimental device without the preprocessing which would be required with the conventional ESPRIT algorithm.