Current controller reduced switching frequency for VS-PWM inverterused with AC motor drive applications

The current control system of the three-phase voltage source inverter used in AC motor drive application is presented in the paper. This system, operating in the rotating reference frame fixed to the motor flux, minimizes the switching frequency inverter transistors. The optimal inverter output voltage vector positions, recorded in an electrically programmable read-only memory, ensure the longest path of moving the stator current vector inside the tolerance band which is square shaped. Theoretical bases for the choice of optimal inverter output voltage vector positions are discussed     

基于瑞萨单片机的交流感应电机驱动电路的设计

介绍一种用于家用电器交流感应电机调速的高性能、低成本变频控制器。针对交流感应电机的控制特点,从功率驱动电路、速度检测、电路保护及EMC等方面进行了分析。控制器核心由低成本高性能的瑞萨单片机和三相功率驱动芯片IRS2136S组成,降低了变频控制器的成本。速度检测采用位置传感器,缩短了软件开发周期。在电路中增加的EMC措施,大大增加了系统的可靠性。该电路已在某些家电产品中得到应用,整机具有良好的稳定性和抗干扰性,通过了UL及国家家电安全标准检验。     

Modulation method for a multiple drive system based on a two-stage direct power conversion topology with reduced input current ripple

A new two-stage multi-drive direct power conversion (DPC) topology suited for multi-drive application is proposed, having an input port for a three-phase power supply and several output ports to connect three-phase loads, which are independently controlled and allow for sine wave in-sine wave out operation. This is a cost effective topology compared to a standard matrix converter because the multiple three-phase loads share the cost of the controlled rectification stage. A new method to reduce the high frequency ripple from the input current is also proposed based on interleaving the switching patterns of the inversion stages, which have to form two groups, allowing for size reduction of the input current filter. This is validated by experiments on a realistic laboratory prototype, while its limitations are determined by simulations.     

基于储能系统的有源配网能量分层管理研究

文中详述了储能系统在配网中的功能和应用场景,包括最优潮流调流、不间断电源、区域能量管理等,并且,文中提出了一种储能系统能量分层管理控制方法,以统一实现上述不同时间初度下的管理功能。储能系统包括第一、第二两层控制层级,且分别为长时间尺度、短时间控制方式。最后,通过MATLAB/SIMULINK仿真系统有效验证了所提分层控制方法的可行性。     

配网运行方式综合优化管理研究

网络重构、并联电容器组以及分布式电源的选址优化是基于配网扩建管理中,较为经济的调控手段。文中通过优化系统的网络结构、优化配置电容器组以及分布式电源的安装位置以综合改善配网的损耗、系统电压稳定性以及线路负荷均衡度。文中建立了配网多目标优化控制模型;并通过非支配排序遗传算法以及模糊决策分析法求解配网最佳运行方式。最后,通过仿真测试系统验证了综合方式运行优化的有效性。     

An ultrasonic motor drive using a current-source parallel-resonantinverter with energy feedback

An ultrasonic motor (USM) drive using a two-phase current-source parallel-resonant inverter is proposed in this study. A single-phase equivalent model of the USM is first described. Then, a detailed theory for the newly designed driving circuit for the USM, in which the inherent parasitic capacitances formed by the polarized piezoelectric ceramic of the USM are parts of the two parallel-resonant tanks, is introduced. Since the dynamic characteristics of the USM are greatly influenced by the variation in the quality factors of the parallel-resonant tanks, two transformers are added to feed the stored energy in the resonant tanks back to the DC source to reduce the quality factors. Detailed experimental results are provided to demonstrate the effectiveness of the proposed driving circuit     

基于区域电能均衡策略的分布储能系统研究

为了使得区域内分布式储能系统保持电能均衡,文中提出了一种基于成本收益分析的微电网(MG)储能系统优化配置方法。分别建立了孤岛模式和并网模式下MG的分布储能系统(DESS)最佳储能容量数学模型,最终将其转化为混合线性整数问题(MLIP),结合数学规划的建模语言(AMPL)进行求解。通过实例分析结果表明:所提出的方法在孤岛模式和并网模式下均可以确定DESS的最佳储能容量,且并网模式下安装DESS可增加MG的总收益,孤岛模式下安装DESS可减小MG的总成本。     

A four-level inverter based drive with a passive front end

Multilevel inverters are suited for high power drive applications due to their increased voltage capability. Specifically, as compared to three level inverters, for a given DC bus voltage, a four-level inverter is able to synthesize better waveforms with reduced device ratings. In a medium voltage drive, a conventional diode bridge rectifier is a low cost multilevel solution if the DC bus voltages can be balanced from the inverter side alone. In this paper, operation of a four-level drive with a passive rectifier is investigated, and modulation constraints of the inverter, arising from the capacitor voltage balancing requirements are examined. Simulation and experimental results are presented to demonstrate the link voltage balancing strategy and the performance of the four-level drive     

Modeling and analysis of multiple access channel capacity based on hybrid energy storage and energy harvesting

Energy harvesting (EH) has been considered as a promising technology to solve the constrained energy problem in the devices of IoT with its advantages of flexible deployment and sustainable energy supply.For multiple access channel with energy harvesting,a hybrid energy storage structure model composed by super capacitor and battery was proposed for the devices of IoT.According to the peculiarities of medium access channel and energy harvesting system,an optimized energy allocation strategy with exponential-type decline (ETD) was presented,the upper and lower bounds of the average throughput were deduced,in particular,the gap of two bounds was derived to be a constant.The channel capacity was further obtained by utilizing the relationship between the average throughput and the channel capacity.In the simulations,the effect of harvested energy,storage capacity and the number of nodes on the channel capacity were analyzed respectively.Experiment results show that compared with the conventional wireless node with single battery storage,the proposed hybrid energy storage structure can improve the harvested energy value and increase the multiple access channel capacity by using adaptive modulation scheme when transmitting the signals.     

基于飞轮储能的新型动态电压恢复器的研究

提出一种基于飞轮储能的新型动态电压恢复器(DVR),其可对深度电压暂降进行补偿;大功率、高储能量的飞轮储能单元成本高昂,为提高飞轮的总储能量,采用飞轮储能阵列,各台飞轮储能单元并联连接于同一直流母线.详细分析该系统的工作原理和各部分的控制策略;对飞轮储能阵列运行于放电状态的控制策略进行了研究,提出了一种新型的放电控制策略.最后利用Matlab/Simulink对系统进行仿真,验证了所提拓扑结构及控制策略的可行性.     

主被动结合的储能电站分布式能源孤岛检测方法

为了提高储能电站分布式能源输出控制能力,需要进行储能电站分布式能源孤岛检测,提出基于主被动结合的储能电站分布式能源孤岛检测方法。首先分析储能电站的实时负荷优化分配模型,采用配电增益调度的方法,进行储能电站的实时负荷预测,利用储能电站的能量负载实时调度的方法进行输出转换控制。然后根据储能电站群的总负荷进行储能电站分布式能源信息评估,采用主被动结合的方法进行储能电站分布式均衡控制,最后通过电站三层负荷开销进行输出负载调节,实现储能电站分布式调节和总发电负荷指令控制,实现储能电站分布式能源孤岛检测。     

基于模糊PI的复合电源双向DC-DC变换器研究

针对电动汽车复合电源中基于传统PI的双重移相控制双有源桥DC-DC变换器在负载和输入电压出现扰动时存在动态响应速度慢和超调量大的缺陷,通过有机结合传统PI和模糊逻辑控制,提出基于模糊PI的双重移相控制策略。首先分析双重移相控制下变换器的具体工作过程和功率特性,然后阐述基于模糊PI的双重移相控制实现方式,并详细说明模糊PI控制器的设计方法。最后通过实验论证所提出的控制策略可以有效提高变换器的动态响应速度和鲁棒性,减小输出电压波动。     

Regenerative properties of wavelength converters based on FWM in a semiconductor optical amplifier

A detailed experimental investigation of the regenerative properties of the four-wave mixing (FWM) for the conventional nonreturn-to-zero data format is reported. A key feature in the proposed scheme, and contrary to the conventional approach, is application of the ON-OFF keying modulation on the pump wave. Measurement of the static transfer functions of the FWM process in a semiconductor optical amplifier shows that certain operating regimes exist, mainly related to the power levels "one" and "zero" of the modulated pump, where a significant improvement of the extinction ratio (ER) can be achieved. This conclusion has been confirmed by dynamic measurements at 2.4 Gb/s, where up to 3-dB improvement in the ER has been observed.     

基于交流采样的电网电压智能监测仪的设计

针对电网电压的监测,通过交、直流采样方法对比,选用交流采样方法,设计开发了智能型电网电压监测仪,详细介绍了系统的硬件和软件设计.该系统有效减少了采样中的非线性环节,提高了采样精度,设计的仪表可实现单台独立工作,也可通过与PC机通讯,进行集中监控,适用于工业用电量采集等应用场合.     

基于交流采样的电网电压智能监测仪的设计

针对电网电压的监测,通过交、直流采样方法对比,选用交流采样方法,设计开发了智能型电网电压监测仪,详细介绍了系统的硬件和软件设计。该系统有效减少了采样中的非线性环节,提高了采样精度,设计的仪表可实现单台独立工作,也可通过与PC机通讯,进行集中监控,适用于工业用电量采集等应用场合。     

太阳能供电半导体制冷技术在低温储粮中的实验研究

粮食储藏问题历来至关重要。近几年来,研究表明,低温储藏能够很好地解决传统储粮方法中的虫害、霉变等带来的损失。本文设计一个基于太阳能供电驱动半导体制冷的系统,通过ATMEGA16单片机来控制半导体制冷,实现制冷的目的,采用小型密闭空间来模拟武汉某粮仓的实验,通过对实验数据定性和定量分析的方法,得出当目标温度在22℃和18℃制冷效果较好,当目标温度在14℃时制冷效率降低,误差变大。     

Implementation of a learning Kohonen neuron based on a newmultilevel storage technique

A compact implementation of a fully parallel Kohonen network with learning capabilities is described. Implementation issues concerning general neural networks are briefly explored, and an original mixed analog and digital technique for storing discrete voltages on a capacitor is presented. The limitations are discussed, and measurements on the storage dynamics are reported, showing that 8 b of resolution can be achieved. This technique is applied to the realization of a neuron dedicated to Kohonen maps. This neuron has been implemented in a standard 2-μm CMOS technology, and the synaptic functions are very dense. The implementation uses a standard 8-b integer arithmetic. Efficient and consistent encoding of the information, dynamic storage, and the adaptation of the synaptic weights and the synaptic multipliers use simple circuitry, thus leading to a low number of transistors