基于广义周期性的单通道多分量正弦调频信号分离和参数估计

针对噪声条件下的单通道多分量正弦调频(SFM)信号,该文提出一种信号分离和参数提取方法。利用正弦调频信号的广义周期性进行奇异值分解,以求出分量信号的调制频率;通过离散点搜索,估计出分量信号的调频(FM)初始相位、调制指数及载频,并对这些估计值利用信赖域算法进行优化,减小误差;利用内积计算,估计分量信号的幅度和初始相位。此外,还利用自相关矩阵特征值分解估计混合信号的信噪比(SNR),并根据信噪比确定停止分解的阈值。在仿真与分析中,针对具体的信号详细说明了该方法的各步骤,并在不同信噪比条件下分析了该方法的参数估计精确度。     

微弱正弦信号的最小二乘拟合检测

本文提出了低信噪比下正弦信号的最小二乘拟合检测方法，理论分析与模拟结果表明了其有效性．     

高效电机提高效率的方法

发展高效节能电机是节约能源和保护环境的客观要求,是科学技术进步的必然趋势,同时也是三相交流电动机的发展方向。     

Direct estimation of noisy sinusoids using abductive networks

Spectral estimation techniques have been used for many years. In many cases, their complexity warrants investigating machine-learning alternatives where intensive computations are required only during training, with actual estimation simplified and speeded up. This allows using simple portable apparatus for fast and automated estimation in real time. We propose using abductive network machine learning for estimating both the amplitude and frequency of a single sine wave in the presence of additive Gaussian noise. Models synthesized by training on 1000 representative simulated sinusoids were evaluated on 500 new cases. With no phase variations and a signal to noise ratio of 7 dB, average absolute percentage errors for the sinusoid amplitude and period are 8.4% and 3.6%, respectively. Effects of the range of frequency variations and the noise level on the complexity and accuracy of the models were investigated. Amplitude and period estimates show signs of bias at a signal to noise ratio of 3 dB. Error variances track the Cramer-Rao bounds at high noise levels, with no thresholding observed down to 0 dB. The method is compared with a neural network model and with conventional discrete Fourier transform (DFT) based techniques and a Prony's based approach. The new approach is particularly useful when only a small portion of the sinusoid cycle is measured.     

A fast,simple and accurate time-varying frequency estimation method for single-phase electric power systems

This paper presents a simple and accurate method to estimate time-varying frequency for single-phase electric power systems, based on three equally spaced samples. A sinusoidal voltage signal model, without dc offset, with time-varying frequency was assumed. Analytical formulas are derived. The method shows good estimation accuracy over a real world wide range of frequency changes. Simulations have been performed.     

正弦信号波形参数拟合求解的混合优化算法

介绍了当前正弦曲线拟合法参数求解过程,从理论上对求解的关键问题进行了分析,提出了基于遗传算法和单纯形法的正弦曲线拟合求解方法.实验结果表明:该混合优化算法能够在参数初值范围较大的情况下快速、精确求得目标函数的全局最优解,获得正弦信号模型的波形参数.     

三相SPWM电压型逆变电源仿真建模和特性分析

为了缩短对大功率电子装置(如逆变电源)的研制周期和减少研制费用,借助计算机仿真技术,利用Matlab软件中Simulink和Power System B lochset建立了以IGBT(绝缘栅双极性晶体管)为开关器件具有数字PI调压功能的SPWM电压型逆变电源仿真模型,对其输出特性进行仿真,并利用傅里叶快速变换(FFT)分析工具对其仿真输出电压进行谐波分析。仿真模型分别考虑了主电路和控制器模型,较为精确地反映了实际情况,验证了此模型和仿真方法的正确性,同样适用于其他电力电子线路。     

阻尼正弦瞬变信号源研制中的几个问题

在典型的R-L-C振荡放电电路中，引入555时基电路和水银继电器作为控制电路．设计了阻尼正弦瞬变信号发生器。并经过实际测试，测试结果达到了要求。     

ESTIMATING THE NUMBER OF TERMS IN A SINUSOIDAL REGRESSION

Abstract. A procedure based on the automatic information criterion procedure of Akaike is presented for estimating the number of sinusoidal terms present in a time series. The procedure is shown to produce a strongly consistent estimator.