汽轮机补偿式胀差算法的改进

汽轮机补偿式胀差测量采用安装双传感器的方法来实现,但一般的补偿式胀差测量对传感器的安装位置有十分苛刻的要求,为此在胀差监视器中引入含剪切因子β的补偿式胀差算法,用数学方法来解决测量误差问题,因而降低了传感器对安装精度的要求,简化了传感器的安装,避免了因传感器问题引起的测量误差.     

消谐动态无功补偿装置在橡胶行业的应用分析

橡胶行业中的密炼系统电动机耗电量大,非线性干扰性负荷变化迅速,易导致电力系统高次谐波,造成谐波危害。对密炼系统加装消谐动态无功补偿装置可以有效滤除谐波。通过分析具体数据,计算装置投入后的节电效果、技术经济分析及投入产出比较。消谐动态无功补偿装置已成为橡胶行业节电工作的一种有效措施。     

注入式混合型有源电力滤波器控制器的研制

针对配电网10 kV高压侧对大容量谐波抑制和无功补偿的要求,提出了注入式混合型有源电力滤波器(IHAPF)拓扑结构.在分析其基本工作原理的基础上,建立了IHAPF的数学模犁.针对其数学模型,提出采川递推积分算法进行控制,可以实现给定电流的尤稳态误差跟踪和对负载扰动信号的抑制,因为对控制器的实时性要求比较高.采用了双DSP控制器.并对控制器的硬件结构组成以及所包含的软件功能模块进行了说明.实验结果证明了所采用控制算法及控制器软硬件结构的有效性.     

Simultaneous wireless information and power transfer with fixed and adaptive modulation

Activating Wireless Power Transfer (WPT) in Radio-Frequency (RF) to provide on-demand energy supply to widely deployed Internet of Everything devices is a key to the next-generation energy self-sustainable 6G network. However, Simultaneous Wireless Information and Power Transfer (SWIPT) in the same RF bands is challenging. The majority of previous studies compared SWIPT performance to Gaussian signaling with an infinite alphabet, which is impossible to implement in any realistic communication system. In contrast, we study the SWIPT system in a well-known Nakagami-m wireless fading channel using practical modulation techniques with finite alphabet. The attainable rate-energy-reliability tradeoff and the corresponding rationale are revealed for fixed modulation schemes. Furthermore, an adaptive modulation-based transceiver is provided for further expanding the attainable rate-energy-reliability region based on various SWIPT performances of different modulation schemes. The modulation switching thresholds and transmit power allocation at the SWIPT transmitter and the power splitting ratios at the SWIPT receiver are jointly optimized to maximize the attainable spectrum efficiency of wireless information transfer while satisfying the WPT requirement and the instantaneous and average BER constraints. Numerical results demonstrate the SWIPT performance of various fixed modulation schemes in different fading conditions. The advantage of the adaptive modulation-based SWIPT transceiver is validated.     

An Algorithm to Detect the Presence of 3D Target Motion from ISAR Data

We present an algorithm to detect the presence of 3D target motion from ISAR data. Based on the 3D point scatterer model, we first examine the effect of 3D motion on ISAR imaging. It is shown that existing motion compensation algorithms cannot properly focus targets exhibiting 3D motion during the imaging interval. An algorithm is then derived to blindly detect the degree of 3D target motion from raw radar data. It is based on measuring the linearity of phases between two or more point scatterers on the target. The phase estimation is implemented using the adaptive joint time-frequency technique. Examples are provided to demonstrate the effectiveness of the 3D motion detection algorithm with both simulation and real ISAR data. The detection results are corroborated with the truth motion data from on-board motion sensors and correlated with the resulting ISAR images.     

Adaptive Stabilization for a Class of Dynamical Systems with Nonlinear Delayed State Perturbations

The time delays and uncertainties are always encountered in varies of engineering systems, and are the major sources of instability. It is important to investigate the stability and stabilization of those systems. A great deal of attention has been devoted in recent years to the stability analysis and design of controller for the linear uncertainty systems with time-delays[1-7] . For the systems with pseudolinear delay state perturbations, the effective controller also has been designed[8]. It…     

New ISFET interface circuit design with temperature compensation

An integrated and new interface circuit with temperature compensation has been developed to enhance the ISFET readout circuit stability. The bridge-type floating source circuit suitable for sensor array processing has been proposed to maintain reliable constant drain-source voltage and constant drain current (CVCC) conditions for measuring the threshold voltage variation of ISFET due to the corresponding hydrogen ion concentration in the buffer solution. The proposed circuitry applied to Si₃N₄ and Al₂O₃-gate ISFETs demonstrate a variation of the drain current less than 0.1 μA and drain-source voltage less than 1 mV for the buffer solutions with the pH value changed from 2 to 12. In addition, the scaling circuitry with the V_T temperature correction unit (extractor) and LABVIEW software are used to compensate the ISFET thermal characteristics. Experimental results show that the temperature dependence of the Si₃N₄-gate ISFET sensor improved from 8 mV/°C to less than 0.8 mV/°C.     

一种新的自适应OFDM算法的探讨

在具有多径干扰的无线信道中仅应用传统OFDM既影响通信速率,也浪费资源.由于信道的频率选择性衰落,OFDM系统的每个子信道具有不同的传输能力.文中提出一种计算量较小、简单实用的自适应OFDM算法,在保证通信质量所需BER的前提下,按照各个子信道衰落程度动态的分配比特和功率,使所需要的发射总功率最小.仿真结果表明,采用该自适应OFDM算法可以提高OFDM系统的性能.     

自适应波束形成的SARLS算法

提出了一种改进的递推最小二乘(RLS)算法——子阵异步RLS算法(SARLS)用于自适应波束形成,改进后的算法,在总权矢量的维数为N、子权矢量维数较小时,运算量由O(N2)降到了O(N),并通过实例仿真详细地验证了算法的实用性:该算法在保持对期望信号良好接收的同时,能够很好地抑制到达方向与期望信号不同的干扰信号。     

激光自适应引信的设计

激光引信在军事上发挥着越来越重要的作用。然而在打击目标时,由于导弹的旋转,目前技术很难解算出导弹距离地面的高度,因此给精确打击目标带来一定困难。激光自适应引信方案旨在解决此问题。首先论述了激光引信的工作原理,然后介绍了本方案的理论基础,最后论述了方案中关键技术、解决方案及本方案的优点。