共查询到19条相似文献,搜索用时 187 毫秒
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为了解决航空三相静止变流器输出波形失真问题,详细分析了死区效应造成电压畸变的原因和由此带来的谐波成分.采用正弦脉宽调制(SPWM)控制技术,使变流器输出的波形更接近于正弦波,提出了设置死区与电压补偿相结合的控制方法,并通过SABER进行了仿真分析.同时,利用TMS320F2812数字芯片实现了相应的补偿策略.仿真和试验结果证明了该控制方法的有效性. 相似文献
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荀磊 《自动化技术与应用》2009,28(11):132-134
特定谐波消除是一种以消除某些特定谐波为目的的优化脉宽调制方法。与其它脉宽调制技术相比,具有消谐性好,输出波形质量高,电力电子器件开关频率低,开关损耗小,电压利用率高等特点。本文主要讨论利用DSP芯片TMS320F2812来实现特定脉宽调制波的方法并给出实现了的波形。 相似文献
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《工矿自动化》2021,47(10)
目前矿用变频器与工频变压器分离放置,占用过多井下工作空间,且变频器输出电压谐波含量高、波形质量差。针对上述问题,分析了变压器工作频率与体积的理论关系,得出在传输功率相同的情况下,与工频变压器相比,高频变压器的尺寸更精简,体积更小,功率密度更高。用电力电子变压器(包含高频变压器的DC-DC变换器)取代常见拓扑中的中间滤波电容,提出了一种基于电力电子变压器隔离变压的复合矿用变频器拓扑结构,该拓扑中全控型开关器件IGBT的数量仅为全部功率器件数量的一半,变频器结构更紧凑、体积更小,且减少了开关损耗,降低了硬件复杂度和生产成本,提升了效率和可靠性。给出了该拓扑中三相整流输入级、中间隔离变压传输级和三相变频输出级的控制策略,采用120°坐标系下快速空间矢量脉宽调制(SVPWM)算法控制输出级,以输出理想的可变频三相对称正弦交流电压。通过仿真和实验分析该变频器各级的稳态和动态特性,结果表明:该变频器可实现变频输出及电压等级的二次变换,输出调压范围更灵活;120°坐标系下快速SVPWM算法降低了输出电压谐波含量,输出的三相电压波形良好。 相似文献
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在电力机车牵引变流器优化控制的研究中,动车组牵引变流器是动车组完成电能转换和传递的关键部件,性能好坏直接关系到动车组能否安全可靠运行。针对CRH2A型牵引变流器输出电压变化率大、谐波含量高等问题,对多电平技术在牵引变流器中的应用进行了研究。首先分析了二极管箝位型五电平变流器(DCMLC)和模块化五电平变流器(M2LC)的工作原理及控制策略,分别构建了牵引变流器的优化模型;并根据CRH2A型牵引变流器主电路实际设计参数应用Matlab仿真软件对五电平DCMLC和M2LC分别进行了建模和仿真,比较和分析了牵引变流器中不同逆变器电路拓扑结构及其对应的控制策略对系统输入输出性能的影响。仿真结果初步验证了两种优化模型对CRH2A型牵引变流器性能的改善效果。 相似文献
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本文介绍了一种新型的PWM逆变器,根据在一个采样周期内期望输出的正弦波面积来实现脉宽调制的,通过设计的年电路和软件在实验中获得了满意的实时,快速性能。从摄取的波形和进一步在伺服系统中的应用表明,这种PWM具有低速性能好,谐波成分少,无论做成调速系统还是构成伺服系统都能有良好的动,静态特性。 相似文献
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本文提出运用线性函数和组合波形原理推导任意N通道交错并联拓扑输出电流纹波幅值的数学模型,为设计具有最优输出电流纹波特性的交错并联拓扑奠定了理论基础。 相似文献
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Decentralized output voltage tracking of cascaded DC–DC converters is an interesting topic to obtain a high voltage conversion ratio. The control purpose is challenging due to the load resistance changes, renewable energy supply voltage variations and interaction of the individual converters. In this paper, four novel decentralized adaptive neural network controllers are designed on the cascaded DC–DC buck and boost converters under load and DC supply voltage uncertainties. In the beginning, individual buck and boost converter average models that can operate in both continuous and discontinuous conduction modes are derived. Then, the interconnected and decentralized state-space models of cascaded buck and boost converters are extracted. These models are highly nonlinear with unknown uncertainties which can be estimated by neural networks. Further, two decentralized adaptive backstepping neural network voltage controllers are proposed on cascaded buck converters to deal with uncertainties and interactions. However, these control strategies are not applicable to a boost converter due to its non-minimum phase nature. Then, two novel decentralized adaptive neural network with a conventional proportional–integral reference current generator are developed on the cascaded boost converters. Practical stability of the overall system is guaranteed for the proposed controllers using Lyapunov stability theorem. Finally, four control strategies provide good quality of output voltage in the presence of uncertainties and interactions. Comparative simulations are carried out on cascaded buck and boost converters to validate the effectiveness and performance of the designed methods. 相似文献
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介绍了模块化多电平换流器的拓扑结构和工作机制,建立MMC数学模型,将电容均压控制算法运用到不同调制策略中以实现电容电压的稳定.在Matlab-Simulink及RT-LAB半实物仿真平台下搭建7电平的逆变器仿真模型,验证最近电平逼近调制的优势.结果表明最近电平逼近调制策略下换流器运行正常,输出波形质量高、谐波含量少、子模块电容电压波动小,在电平数较高的应用场合中具有较大的优势;并证明了Matlab-Simulink和RT-LAB仿真结果的一致性以及RT-LAB仿真效率的高效性. 相似文献
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In this research work, single-stage fifteen levels cascaded DC-interface converter (CDDCLC) is proposed for sun arranged photovoltaic technology (PV) applications. The proposed geography is joined with help DC chopper and H-associate inverter to upgrade the power converter to accomplish the diminished harmonic profile. In assessment with the customary inverter structures, the proposed system is used with diminished voltage stress, decreased switch count and DC source tally. The proposed research work with cascaded DC link converter design requires three DC sources for combining fifteen-level AC output. This investigation structure switching technique is phase opposition and disposition pulse width modulation technique (POPD) which results in improved quality of obtained output AC power with 6.73% THD and also determinedly recommended for power converters used in UPS and drive applications since it is extremely affordable. A simulation and prototype model of fifteen-level CDDCLC system is deployed and its performance is analyzed for various operating conditions. 相似文献
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为了验证逆变电路中不同调制技术的输出特性,基于三相桥式逆变电路,对几种恒频调制技术进行对比分析。针对基本三相桥式逆变电路和三相桥式MMC(Modular Multilevel Converter)电路,采用PWM、SVPWM、载波移相、载波层叠及最近电平逼近调制(Nearest Level Modulation,NLM)等恒频调制技术对其进行控制,搭建Matlab/Simulink仿真,仿真分析不同调制方法下输出线电压波形,对直流电压利用率、总谐波畸变率(Total Harmonics Distortion,THD)和功率损耗进行分析比较。仿真结果表明,当拓扑为基本三相桥式逆变电路时,除NLM外,各调制方法均能满足电能质量国家标准THD规定,但直流电压利用率相差较大;当拓扑为三相桥式MMC电路时,分别采用载波移相、载波层叠及NLM实现了七电平MMC的调制。 相似文献