三电平四桥臂有源电力滤波器的预测电流控制研究

为解决三电平四桥臂结构开关矢量多、计算量大及控制复杂等问题,重点研究适用于三电平四桥臂结构的电流预测控制策略,并通过建立Matlab模型,进行理论分析和仿真研究。仿真和实验结果表明:采用预测电流控制方法的有源电力滤波器对谐波电流和中线电流有较好的补偿效果,并能有效地控制直流侧电压平衡。     

直流大电流比较仪谐波影响问题的研究

本提出了在谐波影响下直流大电流比较仪的等效电路模型及计算方法,通过仿真给出了该模型的频率特性,通过试验数据与仿真结果的比较证实了电路模型的可行性,对研究直流大电流比较仪和电流互感器的谐波影响具有指导意义。     

A基于MATLAB／Simulink的零磁通电流传感器仿真模型

本文根据零磁通传感器原理，在MATLAB／Simulink的软件环境下，对零磁通电流传感器的整体模块进行了建模、仿真与分析。根据仿真后得到的数据证明了零磁通原理与仿真模型的正确性，同时为零磁通电流传感器的研制提供了一种新思路。     

球墨铸铁机械性能的优化模型

通过对球墨铸铁机械性能影响因素的分析，指出在一定的生产条件下，球墨铸铁的机械性能主要取决于组织、成分。利用Matlab中的Neural Network Toolbox仿真环境和BP模型算法建立了球墨铸铁机械性能的优化模型，详细论述了模型结构的设计、数据处理、网络初始化、训练与仿真的过程。该方法对提高球墨铸铁的机械性能具有积极作用。     

缓冲包装系统计算机仿真的应用研究

研究缓冲包装系统计算机仿真流程、仿真模型的建模理论及方法，采用VB语言、Mat-lab/Simulink仿真工具进行Windows操作环境下缓冲包装系统的仿真，可避免不必要的破坏性试验，减少试验费用，反复修改模型参数、优化缓冲包装结构及尺寸。     

结构连续分布的动态随机载荷识别方法研究

复杂结构连续分布的动态随机载荷识别技术是结构动载荷识别技术的难点之一。推导了基于广义正交多项式特征技术动态随机载荷识别模型，馋决了在一定精度范围内通过有限测量部位随机振动响应信息识别无限未知量的结构分布动态随机载荷的关键技术，通过动态标定技术的研究和复杂结构有限元模型数值仿真计算验证了方法的正确性、有效性和工程可用性，适用于具有沿结构分布的振动随机载荷识别，为分布动态随机载荷识别技术的发展打下一定的基础。     

压电陶瓷致动器的动态控制模型及逻辑规则控制

提出了一种新的压电陶瓷致动器的动态控制模型．该控制模型建立在泛布尔代数理论基础上；它依赖于压电陶瓷的控制经验．通过一系列控制规则，采用泛布尔代数的符号进行控制模型的表述．在所建模型基础上，结合PID控制器对压电陶瓷进行了Rule＋PI控制的离线仿真研究；仿真结果表明，该控制模型结构简单，控制方便，易于实现．     

高空舱排气系统参数化计算平台研究

目前高空舱排气系统仿真计算领域存在几何建模耗时长、仿真流程慢等问题，为解决此类问题，本文根据高空舱排气系统的典型几何结构特点，采用参数化建模方案，通过对基础结构参数化模型的搭配组合形成满足计算要求的高空舱排气系统几何模型。通过对高空舱排气系统的几何模型进行计算网格的自动划分及数值计算，得到高空舱排气系统的流场及温度场分布数据，并与试验结果进行对比验证，结果表明：计算结果与试验结果的相对误差低于3%，满足工程实践要求。在此基础上，采用先进的计算机软件开发技术对上述分析流程进行封装及定制，并结合商业软件的二次开发技术，最终形成参数化的高空舱排气系统仿真软件集成封装平台。利用该平台可快速搭建参数化的高空舱排气系统模型，实现高空舱排气系统的全流程快速仿真，具有高效、便捷、准确等优点。     

Rogowski线圈在高压脉冲大电流测量中的应用

利用Matlab软件的Simulink仿真环境,创建了高压脉冲大电流测量系统的仿真模型,实现对罗氏线圈结构参数的确立和积分器积分常数的优化.给出了一种适合于高压脉冲大电流测量的罗氏线圈的结构设计及其积分电路的设计方法,并将这种测量装置成功应用到脉冲成形网络(PFN)放电系统中.通过在积分电路中加入滤波抗干扰设计,实现了对高压脉冲大电流的测量,克服了冲击电流测量中常规用分流器存在的问题和不足.     

混合FE-SEA方法预测高速列车车体结构隔声量

针对高速列车车体结构刚度大，结构复杂的特点，采用混合FE-SEA方法建立基于混响室以及混响室-消声室的两种隔声量预测模型，通过仿真结果对比，两种模型预测的隔声量结果相同，将仿真结果与实测值对比，结果表明，在100 Hz～1 000 Hz的中频范围内FE-SEA模型的预测结果与试验结果吻合良好，混合FE-SEA方法可以有效用于高速列车车体结构的隔声量预测。     

Analytical evaluation of DC capacitor RMS current and voltage ripple in neutral-point clamped inverters

The sizing of the DC-link capacitor in a three-level inverter is based on the RMS current flowing through it. This paper analyses the DC-link capacitor RMS current in a neutral-point clamped (NPC) inverter and expresses the same as a function of modulation index, line-side current amplitude and power factor. Analytical closed-form expressions are derived for the capacitor RMS current for single-phase half-bridge, single-phase full-bridge and three-phase three-leg topologies of a three-level inverter. The worst-case capacitor current stress is determined for each topology based on the analytical expressions. Further, analytical expressions are derived for the RMS values of low-frequency and high-frequency capacitor currents. These expressions are then used to estimate voltage ripple across the DC capacitor for sinusoidally modulated three-phase NPC inverter. The analytical expressions for the RMS current and voltage ripple are validated experimentally over a wide range of operating points.     

Active power decoupling with reduced converter stress for single-phase power conversion and interfacing

Single-phase DC–AC power electronic converters suffer from pulsating power at double the line frequency. The commonest practice to handle the issue is to provide a huge electrolytic capacitor for smoothening out the ripple. However, the electrolytic capacitors having short end of lifetime limit the overall lifetime of the converter. Another way of handling the ripple power is by active power decoupling (APD) using the storage devices and a set of semiconductor switches. Here, a novel topology has been proposed in implementing APD. The topology claims the benefit of (1) reduced stress on converter switches and (2) using smaller capacitance value, thus alleviating the use of electrolytic capacitor and in turn improving the lifetime of the converter. The circuit consists of a third leg, a storage capacitor and a storage inductor. The analysis and the simulation results are shown to prove the effectiveness of the topology.     

Improving the performance of hysteresis direct torque control of IPMSM using active filter topology

This paper describes an active filter topology to improve the performance of hysteresis direct torque control (HDTC) of interior permanent magnet synchronous motor (IPMSM). The filter topology consists of an active filter and two RLC filters, and is connected to the main power circuit through a 1:1 transformer. The active filter is characterized by detecting the harmonics in the motor phase voltages and injecting equivalent harmonic voltages to produce almost sinusoidal voltage waveform to the motor terminals. The active filter uses hysteresis voltage controller while the motor main circuit uses hysteresis direct torque control. The simulation results of this combined control structure show considerable torque ripple reduction in the steady state range and adequate dynamic torque performance as well as considerable harmonic voltage and EMI noise reduction.     

混合储能系统分散自适应强扭曲虚拟阻抗控制

为提高负载冲击条件下混合储能系统(hybridenergystoragesystem,HESS)的稳定能力,考虑模型不确定及上界未知等现实约束,基于自适应高阶滑模控制理论,提出一种分散自适应强扭曲虚拟阻抗控制(decentralized adaptive super-twisting virtual impedance...     

反激变换器输出纹波电压分析与测量

针对反激变换器输出纹波电压比较大的缺点,分别分析了连续电流模式(CCM)、断续电流模式(DCM)的能量传输过程,并通过能量传输过程中反激变压器次级线圈电流和输出电容电压之间的关系,从根本上得出了反激变换器纹波产生的机理;对于纹波测量,总结出了三种正确的测量方法,并介绍了各种测量法的相关测量装置及相应注意事项,简述了EIAJ-RC9002A测量标准。实验测量表明,采用同轴电缆法测量纹波电压正确可行。     

Novel zero voltage switching dual-switch forward converter with ripple current cancellation

A zero voltage switching (ZVS) dual-switch forward converter with ripple current cancellation is presented. In the proposed converter, active clamp circuit is used to clamp the voltage stresses and to realise ZVS of all switching devices. Active clamp boost converter with power factor correction is used in the front stage of the proposed converter to draw a sinusoidal line current from the AC source and to maintain a constant voltage at the DC bus. The second stage of the proposed converter is a dual-switch forward converter with current doubler rectifier to obtain the isolated low output voltage. Active clamp circuit used in the DC/DC converter can recycle the energy stored in the leakage inductor and magnetising inductor so that the voltage stresses on the switches are limited and the ZVS feature is realised. The current doubler rectifier offers the ripple current cancellation at the output capacitor and reduces the current stress of the transformer secondary winding. The circuit configuration and principle of operation are analysed and discussed in detail. Experimental results with a laboratory prototype based on a 90-260 V_rms input and 12 V/30 A output were provided to verify the effectiveness of the proposed converter.     

开关电流高阶椭圆低通滤波器的设计(英文)

提出了一种新的开关电流高阶椭圆低通滤波器通用综合方法,该法遵循从RLC滤波器到有源RC滤波器,再到开关电容滤波器,最后到开关电流滤波器的顺序进行设计,方法简单易行.文中给出了5阶开关电流椭圆低通滤波器的设计实例,ASIZ仿真频率响应满足所需的频率技术要求.     

Feedforward simple control technique for on-chip all-digital three-phase AC/DC power-MOSFET converter with least components

A novel simple control technique for on-chip all-digital three-phase alternating current to direct current (AC/DC) power-metal oxide semiconductor field-effect transistors (MOSFET) converter with least components, which is employed to obtain small current and DC output voltage ripples as well as excellent performance, and using a feedforward simple control method for DC output voltage regulation is proposed. The proposed all-digital feedforward controller has the features of low cost, simple control, fast response, independence of load parameters and the switching frequency, it has no need for compensation, and high stability characteristics; moreover, the proposed controller consists of three operation amplifiers and few digital logic gates that are directly applied to the three-phase converter. The power-MOSFETs are also known as power switches, whose control signals are derived from the proposed all-digital feedforward controller. Instead of thyristors or diodes, the application of power-MOSFETs can reduce the loss of AC/DC converter that is proper to the power supply system. The input stage of an AC/DC converter functions as a rectifier and the output stage is a low pass inductor capacitor (LC) filter. The input AC sources may originate from miniature three-phase AC generator or low-power three-phase DC/AC inverter. The maximum output loading current is 0.8 A and the maximum DC output ripple is less than 200 mV. The prototype of the proposed AC/DC converter has been fabricated with Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mum 2P4M complementary MOS (CMOS) processes. The total chip area is 2.333 1.960 mm². The proposed AC/DC converter is suitable for the following three power systems with the low power, DC/DC converter, low-dropout linear regulator and switch capacitor. Finally, the theoretical analysis is verified to be correct by simulations and experiments.     

Analysis and implementation of a soft switching interleaved forward converter with current doubler rectifier

A soft switching interleaved forward converter with current doubler rectifier is presented. Active clamp circuit is used in the primary winding of transformers to recycle the energy stored in the leakage inductor and the magnetising inductor so that the voltage stresses of switches are reduced. The leakage inductance of transformers, the magnetising inductance and the clamp capacitance are resonant to achieve zero-voltage switching (ZVS) of clamp switches. The resonance between the leakage inductance of transformers and output capacitance of switch will achieve ZVS operation for the main switches in the proposed converter. The interleaved operation can reduce the current ripple on the output capacitor. Two current doubler rectifiers with ripple current cancellation are connected in parallel at the output side to reduce the current stress of the secondary winding of the transformer. All these features make the proposed converter suitable for the DC-DC converter with high output current. The operation principle and system analysis of the proposed converter are provided in detail. Finally, experimental results, taken from a laboratory prototype rated at 125 W, are presented to verify the feasibility of the proposed converter.     

Novel transimpedance filter topology for instrumentation

In this paper, a novel transimpedance filter topology is described. It resembles typical Q-Enhancement configurations. Low- and band-pass responses have been fully developed taking into consideration several parameters such as frequency response, input-output impedances and noise. Design conditions are obtained to optimize the performance. Transimpedance filters find direct application with some sensors and D/A converters which provide a current as output signal, avoiding a current to voltage conversion