随机振动功率谱再现自适应控制算法研究

为提高电液随机振动实验的控制精度,提出了一种基于Kalman滤波器的随机振动功率谱再现实时自适应控制方法。基于参考谱的信息设计FIR滤波器,通过对白噪声信号的滤波生成时域驱动信号。采用Kalman自适应滤波器实时跟踪振动实验系统的阻抗特性,并基于自适应逆控制方法对系统的输入信号进行滤波修正,使得系统的响应信号能够高精度再现时域驱动信号,进而实现参考谱的高精度再现。功率谱再现实验验证了算法的有效性。     

Optimal C-Type Filter Design to Maximize Transformer's Loading Capability under Non-sinusoidal Conditions

The main purpose of this article is to employ the C-type passive filters for maximization of the loading capability of transformers under non-sinusoidal conditions. For this aim, an optimal passive filter design approach is proposed regarding minimization of the harmonic loss factor (F_HL), which is defined in IEEE standard C57.110 to represent the loading capability of the transformers supplying non-sinusoidal load currents. With respect to IEEE standard 519, displacement power factor and individual harmonics & total harmonic distortions of the voltage and current are considered as constraints of the proposed optimal filter design approach. In addition, numerical results are presented to figure out that the proposed approach provides higher loading capability of the transformers under non-sinusoidal conditions when compared with the other two optimal filter design approaches based on minimization of the current total harmonic distortion and minimization of the voltage total harmonic distortion.     

数字技术是发展我国纺机产业的重要途径

分析了我国纺机产业的形势 ,说明了数字技术在纺机技术发展中的重要作用 ,并指出其在制造工艺中的迫切性和实施数字化管理的四个原则 ;建议充分利用社会资源共创数字化纺机企业。     

具有低偏振像差的偏振分色合色系统

提出了一种具有低偏振像差的偏振分色合色系统的设计方法。通过优化设计得到的结果为:短波通膜透射曲线的S、P偏振分离为1.9nm,长波通膜透射曲线的S、P偏振分离为0.8nm;短波通膜和长波通膜合成的S、P偏振位相差在整个工作波长420~680nm为小于29°且大于-10°,相比常规的偏振分色合色系统,偏振像差得到了显著改善。     

并联型有源滤波器的重复学习控制策略参数分析与设计

为了消除谐波抑制过程中重复学习控制器不稳定因素对控制品质的影响,论文以LCL滤波器的有源电力滤波器系统稳定性和补偿性能作为切入点,理论分析了重复学习控制器的参数选取范围,同时仿真结果验证了该理论的正确性和有效性.     

动态电压恢复器软件锁相技术

对动态电压恢复器中常用的软件锁相环进行了研究,针对三相不平衡情况下负序分量对锁相环检测精度的影响,提出了基于数学形态滤波器的软件锁相环.通过选取适当的结构元素,结合形态学的基本运算,设计出低通形态滤波器来抑制由负序分量转换而来的2次谐波,提高锁相环的抗干扰能力和检测精度.理论分析和仿真实验都验证了其可行性,结果表明该方...     

基于无源性的并联型有源滤波器自适应滑模控制

针对有源滤波器电流谐波分量检测复杂且在非线性负载变化时出现电源电流畸变的现象,基于非线性控制理论,从能量平衡关系出发,提出了新型的有源滤波器控制方法.利用本质上是非线性反馈的无源性控制( PBC)策略,实现直流侧电容电压的补偿控制,在非线性负载时变未知情形下,确保系统稳定的同时,实现谐波电流的精确计算与跟踪.基于此,将...     

A low-transconductance OTA with improved linearity suitable for low-frequency Gm-C filters

A fully differential operational transconductance amplifier is presented in this paper with enhanced linearity and low transconductance, suitable for low-frequency Gm-C filters. This paper also proposes a new common-mode feedback scheme that presents low sensitivity to large differential voltage swings at the OTA outputs. The proposed OTA was employed in the design of a fully-integrated Gm-C low-pass filter with a cutoff frequency of 30 kHz. The Gm-C filter was fabricated in a 0.35 μm CMOS technology and presented a THD at the output less than 1% for input signals with differential amplitudes up to 3.2 V.