Digitalization of inverting filter shaping circuit for nuclear pulse signals

In the design of filter shaping circuits for nuclear pulse signals,inverting filter shaping circuits perform better than non-inverting filter shaping circuits.Because these circuits facilitate changing the phase of a pulse signal,they are widely used in processing nuclear pulse signals.In this study,the transfer functions of four types of inverting filter shaping circuits,namely the common inverting filter shaping,improved inverting filter shaping,multiple feedback low-pass filter shaping,and third-order multiple feedback low-pass filter shaping,in the Laplacian domain,are derived.We establish the numerical recursive function models and digitalize the four circuits,obtain the transfer functions in the Z domain,and analyze the filter performance and amplitude-frequency response characteristics in the frequency domain.Based on the actual nuclear pulse signal of the Si-PIN detector,we realize four types of inverting digital shaping.The results show that under the same shaping parameters,the common inverting digital shaping has better amplitude extraction characteristics,the third-order multiple feedback low-pass digital shaping has better noise suppression performance,and the multiple feedback digital shaping takes into account both pulse amplitude extraction and noise suppression performance.

DESIGN OF LIGHTWEIGHT PUF CIRCUIT BASED ON SELECTABLE CROSS-COUPLED INVERTERS

By analyzing the principle of process variations, a lightweight Physical Unclonable Function （PUF） circuit based on selectable cross-coupled inverters is proposed in this paper. Firstly, selectable cross-coupled inverters are chosen for two delay paths. Simultaneously, the circuit takes challenge signal to control each delay path. The PUF cell circuit is implemented in Semiconductor Manufacturing International Corporation （SMIC） 65 nm CMOS technology and the layout area is 2.94μm × 1.68μm. Then the 64-bit PUF circuit is achieved with the cascade connection of cell circuits. The simulation results show that the randomness is 49.4% and the reliability is 96.5%. Compared to the other works, this PUF circuit improves the encrypt performance and greatly reduces the area.

A new multilevel voltage source inverter configuration with minimum number of circuit elements

An advanced configuration for multilevel voltage source converters is proposed. The proposed converter is able to apply asymmetrical DC sources. The configuration of the proposed inverter is well designed in order to provide the maximum number of voltage levels in output terminals using lower number of circuit devices. The authority of the proposed inverter versus the conventional H-bridge cascaded inverter and the most recently introduced ones, is verified with a provided comparison study. The proposed inverter is able to generate the desired voltage levels using a lower number of circuit devices including power semi-conductor switches, IGBTs, diodes, related gate driver circuits of switches and DC voltage sources. As a result, the total cost and installation area are considerably reduced and the control scheme gets simpler. To confirm the feasibility of the proposed multilevel structure, both the simulation and experimental results are provided and compared which shows good agreements.

Computer simulation of short-circuiting transfer welding under waveform control on inverter power source

A simulation model is introduced about the non-linearity process of short-circuiting transfer in CO2 arc welding for displaying the interaction between the inverter power source and welding arc under waveform control. In the simulation model, the feedback signals of current and voltage are taken respectively at the different phase in a short circuit periodic time and applied to the PWM （pulse width modulation） module in a model of inverter power source to control the output of power source. The simulation operation about the dynamic process of CO2 short-circuiting transfer welding is implemented on the founded simulation model with a peak arc current of 400 A and a peak voltage of 35 V, producing the dynamic arc waveforms which can embody the effect of inverter harmonic wave. The simulating waveforms are close to that of welding experiments.

A Novel Multilevel Inverter Circuit for the Performance Enhancement of Direct Torque Controlled Induction Motor

Induction motor is the most sought after motor in the industry for excellent performance characteristics and robustness. Developments in the Power Electronic circuitry have revolutionised the induction motor industry leading to the developments in various control strategies and circuits for motor control. Direct Torque Control (DTC) is one of the excellent control strategies preferred by industries for controlling the torque and flux in an induction machine. The main drawback of DTC is the presence of torque ripple which is slightly more than the acceptable limit. There are various parameters that introduce ripples in the electromagnetic torque, one of them being the type of inverter circuit. There are various types of inverter circuits available and the effect of each of them in the production of torque ripple is different. This work is an attempt to identify the influence of various multilevel inverter circuits on the torque ripple level and to propose the best inverter circuit. The influence of multilevel diode clamped inverter and cascaded H bridge inverter circuits on torque ripple minimization, is analysed using simulation studies for identifying the most suitable multilevel inverter circuit which gives minimum torque ripple. The results obtained from the simulation studies are validated by hardware implementation on 0.75 kW induction motor.

基于电路等效的并网逆变器失稳分析与稳定控制

以并网逆变器为功率接口的新能源发电系统在弱电网条件下易发生振荡失稳问题。该文将并网逆变器的控制回路可视化为电路元件组成的虚拟阻抗,基于该电路模型分析了弱电网条件下电流内环与锁相环交互作用导致并网逆变器振荡失稳的机理,在此基础上,提出了基于有源阻尼的稳定控制设计方法,并对不同有源阻尼控制的电路特性以及稳定性提升能力进行了对比分析。研究结果表明,针对锁相环引入负电阻造成的振荡失稳问题,阻抗-高通滤波器型有源阻尼控制策略具有更优的稳定性提升能力。最后通过PSCAD/EMTDC仿真和远宽StarSim控制器硬件在环实验对比了不同有源阻尼控制策略的振荡抑制效果,并验证了阻抗-高通滤波器型有源阻尼控制的动态性能。结果表明,所设计的稳定控制能够在200 ms内有效抑制系统振荡,并且可实现在短路比为1的极弱电网条件下稳定运行。

面向残差评价的中点钳位型逆变器开路故障诊断方法

在基于解析模型的故障诊断系统中,为了显化残差信号所包含故障信息的能力,提出一种面向残差评价的中点钳位型三电平三相逆变器快速开路故障诊断方法。首先,构建诊断观测器获取三相电流观测值并通过观测矩阵计算电流残差;其次,通过引入基于范数的标准评价函数,计算残差性能指标与阈值,将残差转换为可用的特征信号并与阈值相比较实现高效实时的故障检测;再次,推导不同功率开关器件开路故障状态下的电流残差特性,并依据此特性实现精准的故障隔离;最后,在仿真平台及半实物实验平台上验证了该文所提算法的有效性与可行性。仿真与实验平台结果表明,相较于传统基于信号与知识的诊断方法,残差性能评价的引入使得诊断速度提高80%以上。针对NPC型三电平三相逆变器常见的四种开路故障情况,均可实现快速且精准的故障检测及定位。

An Approach to Equivalent Circuit Modelling of Inverted Organic Solar Cells

A low temperature sol-gel process was used to fabricate zinc-oxide and yttrium-doped zinc oxide layers. These zinc-oxide and yttrium-doped ZnO films were used as electron transport layers in conjunction with P3HT and PC16BM type solar cells. It was demonstrated that annealing and doping of electron transport layer influenced the overall organic solar cells performance. Anneals of ~ 150?C provided the highest device performance. Compared to the undoped zinc oxide, the device with yttrium doped zinc oxide layers showed improved efficiency by about 30%. Furthermore an equivalent circuit was proposed to understand the connection between the electrical and optical characteristics of the device. Comparisons between the simulated and experimental current-voltage(I-V) curves displayed only a 1.2% variation between the curves. Clearly, our experimental and simulated studies provide new insight on the equivalent circuit models for inverted organic solar cells and further improvement on photovoltaic efficiency.

模块化多电平逆变电路的调制算法研究

针对永磁同步电机传统三电平逆变电路无法满足高压场景的问题,采用空间矢量脉宽调制算法对模块化多电平逆变电路进行调制分析,观察其输出电压波形。然后针对模块化多电平逆变电路各相之间容易出现环流现象,对电容电压平衡控制算法进行简化。在Matlab/Simulink中搭建模型仿真,观察和分析模块化多电平逆变电路的输出电压,实验结果验证了采用空间矢量脉宽调制算法对改善模块化多电平逆变电路的输出特性的有效性和简化后的电容电压平衡控制算法具有稳定性。

单相不间断电源逆变电路调制度对输出电压谐波的影响

详细分析单相不间断电源核心部分(逆变电路)的特点、类型、评价指标及控制方式,然后采用广泛应用的单相双极性正弦脉冲宽度调制法的全桥逆变电路作为研究对象,导出了逆变电路输出平均电压的表达式,采用仿真和理论相结合的方法讨论了频率调制度和幅值调制度的典型取值对输出电压谐波的影响.讨论结果表明,当载波频率为调制波频率的奇数倍时,取幅值调制度r=0.9左右,而当载波频率为调制波频率的偶数倍时,取幅值调制度r=0.5左右,此时输出逆变电压波形质量更好,谐波含量较小,对于改善逆变电路的设计和参数选择具有一定的参考价值.

逆变型电源场站故障稳态电流实用化计算方法

单机倍乘法常用于逆变型电源场站的故障稳态建模,可简单估算场站短路电流水平,但计算精度有待提升。文中首先分析了低电压穿越控制策略约束下,有功出力、电压跌落程度对发电单元输出的稳态电流的决定性作用,得出故障稳态电流输出特性曲线,基于此分析了场站电气距离及有功出力差异对单机倍乘法计算误差的影响。在误差分析的基础上,提出了计及发电单元分布特性的改进单机倍乘法。该方法在发电单元接入点电压计算中,利用等值阻抗来等效发电单元与并网点的电气距离;将场站分群等值为两台机组,减小发电单元间有功出力差异对短路特性的影响。不同场景下的仿真分析表明,改进方法计算精度较单机倍乘法有着较大的提升。所提方法仅需通过简单计算即可实现场站分群和短路电流聚合,有较好的工程实用性。

Design of Low-Voltage, Low-Power FGMOS Based Voltage Buffer, Analog Inverter and Winner-Take-All Analog Signal Processing Circuits

This paper proposes novel floating-gate MOSFET (FGMOS) based Voltage Buffer, Analog Inverter and Winner-Take-All (WTA) circuits. The proposed circuits have low power dissipation. All proposed circuits are simulated using SPICE in 180 nm CMOS technology with supply voltages of ±1.25 V. The simulation results demonstrate increase in input range for FGMOS based voltage buffer and analog inverter and maximum power dissipation of 0.5 mW, 1.9 mW and 0.429 mW for FGMOS based voltage buffer, analog inverter and WTA circuits, respectively. The proposed circuits are intended to find applications in low voltage, low power consumer electronics.

改进残差网络的逆变器开路电路故障诊断

针对传统三相电压源逆变器开路故障诊断方法存在准确率低和鲁棒性差的问题,提出一种用于故障诊断的改进二维卷积神经网络优化方法.该方法首先引入一种新的数据预处理方式,通过马尔可夫变迁场(MTF)将原始时域电压信号数据转换成二维灰度图像,有效保留特征的时空关系;其次,提出采用并行注意力机制对卷积神经网络ResNet18特征提取层提取的特征分别进行通道和空间特征筛选,并完成有效特征融合;最后,融合的特征经ResNet18全连接层和输出层得到故障分类结果.实验结果表明,所提出的改进故障诊断方法能将诊断精度提升至99.80%;在不同噪声条件下均能保持90%以上的分类准确性,验证该方法可有效提高逆变器开路故障诊断性能和鲁棒性.

无线电能传输系统全桥逆变器性能优化研究

针对无线电能传输系统中全桥逆变器开关管的开通和关断存在振铃,能量传输波形纹波大,导致逆变器温升大和工作不稳定的问题,进行了电路建模分析,开展了全桥逆变器性能优化研究。首先,对逆变器开关管驱动电路进行了简化,建立了RLC串联谐振电路模型,分析了驱动电路结构参数对逆变器性能的影响规律,得出了优化方法;其次,分析了逆变器纹波大的问题,给出了优化方法;最后,搭建了300 W无线电能传输系统并进行实验。实验结果验证了优化方法的正确性和有效性,逆变器性能得到了改善,温升得到了有效控制,系统传输效率提高了5.3%,整机效率达到了89.3%。

基于谐波注入分段供电永磁直线同步电机变流器开路推力波动抑制

该文提出一种电流谐波注入的方法,减小长定子分段并联供电永磁直线同步电机系统的驱动变流器发生单相开路故障下电机推力波动。首先,根据动子在定子段的位置,推导出分段单元电机的电压方程,得到各个单元电机的推力表达式和系统总推力。然后,依据变流器单相开路前后的全耦合状态下单元电机基波磁动势不变的原则,构造降阶坐标变换矩阵,得到电机的电压方程和推力表达式。采用注入谐波电流、优化故障后直线电机的输出推力的方式,消除变流器单相开路故障产生的4次和6次推力谐波并消除耦合因数变化对电机推力影响;通过多变流器协同控制多单元电机,有效降低变流器单相开路故障后的推力波动,提高电机的最大输出推力。仿真和实验验证该方法的有效性。

新能源汽车驱动电机控制器深度解析

文章针对新能源汽车驱动电机控制器的结构原理进行深度解析,阐述电机控制器的基本结构、基本功能,深入分析逆变电路的逆变原理、能量回收整流原理、正弦交流电产生原理和变压与变频原理,介绍电机控制器驱动电路与控制电路的基本组成与结构特点,对职业院校新能源汽车技术专业教师和新能源汽车维修行业维修人员具有一定的参考和借鉴意义。

4H-SiC CMOS高温集成电路设计与制造

设计、制造并测试了基于碳化硅材料的横向MOSFET器件和CMOS电路。常温时,N型和P型MOSFET在片测试的阈值电压分别约为5.4 V和-6.3 V;温度达到300℃时,N型和P型MOSFET的阈值电压分别为4.3 V和-5.3 V。由N型和P型MOSFET组成的CMOS反相器在常温下输出的上升时间为1.44μs,下降时间为2.17μs,且在300℃高温条件下仍可正常工作。由CMOS反相器级联成的环形振荡器在常温下的测试工作频率为147 kHz,在高温下也可正常工作。

基于输出电压轨迹的三相逆变器开关管开路故障诊断

开关管开路故障会让功率变换器的输出电压与电流产生严重畸变,因而降低了变换器输出的电能质量。开路故障出现后其余功率开关器件的损耗可能增加,所以容易在电路中引发二次故障。文中提出一种针对三相逆变器开关管开路故障的故障诊断方法。故障类型与故障器件的辨识通过分析三相逆变器在αβ平面上的输出电压轨迹实现,仅需要测量滤波后的输出线电压。所提出的方法易于实现,可以诊断三相逆变器的所有开关管开路故障情况。最后,通过仿真和实验验证所提出方法的可行性和准确性。

基于Buck-Boost逆变电路的低纹波可调直流稳压电源控制方法

为克服传统低纹波直流稳压电源的主电路拓扑结构存在电路结构复杂、体积大等不足,提出一种基于Buck-Boost逆变电路的新型可调直流稳压电源拓扑结构,用Buck-Boost逆变环节取代传统结构中高频逆变和变压器升压两个环节,此结构相较于传统结构,在电路结构上可以得到明显的简化。为实现该新型可调直流稳压电源输出低纹波、高稳定度直流电压的要求,针对其Buck-Boost逆变电路提出采用基于比例积分-矢量比例积分的复合控制方法,即以Buck-Boost逆变电路中电容电压和电感电流作为状态变量,并以电感电流为控制内环,电容电压为控制外环,通过对两个闭环采用比例积分-矢量比例积分复合控制方法,实现对两个状态变量的解耦控制,最后通过仿真与实验对其效果进行了验证,同时与传统低纹波直流稳压电源进行了对比分析。结果表明,文中提出的基于Buck-Boost逆变电路的新型可调直流稳压电源拓扑结构及针对该拓扑结构所提出的控制方法不仅输出直流电压纹波小、稳态精度高、动态性能好同时还具有电路结构简单且输出直流电压任意可调等特点,因而具有较好的应用价值。

适用于有源区域电磁波时程精细积分仿真的大时间步长矩阵数值积分方法

时程精细积分(PITD)法是一种全波电磁数值方法,具有相当宽松的数值稳定性条件,且数值色散误差几乎不受时间步长的影响,因而近年来在电磁学领域中受到广泛关注。在有源区域的电磁数值模拟中,PITD法需要计算激励源添加引入的非齐次项所产生的矩阵积分,其计算或存在矩阵求逆运算,易不稳定,或难以在大时间步长下保证计算结果的精度,这使得PITD法的推广应用受到一定限制。该文将响应矩阵法引入有源区域的电磁波PITD仿真中,不仅避免了矩阵的求逆运算,并且能够在保证计算结果精度的条件下,增大时间步长的选择范围,提高算法的计算效率。最后,进行了实例计算,并与直接近似积分方法和数值积分方法的结果进行了对比,验证了该文所提方法的实用性和有效性。