共查询到20条相似文献,搜索用时 46 毫秒
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Zhi Jian Zhou Xing Zhang Po Xu Shen W.X. 《Industrial Electronics, IEEE Transactions on》2008,55(8):2997-3004
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This paper develops a novel pulse-width modulation (PWM) strategy for application in uninterruptible power supply (UPS) and ac motor drive systems. The voltage/current harmonic spectra and other properties of this PWM scheme are thoroughly investigated. This modulation strategy is compared with other modulation techniques, especially with the commonly used sinusoidal modulation scheme, from the standpoints of simplicity, inverter switching losses, motor losses, and other output performance features. This novel modulation scheme produces an acceptable motor curent waveform while keeping the number of inverter commutations low. Implementation of this scheme is quite simple in hardware-based as well as microprocessor-based systems. 相似文献
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Busada C.A. Chiacchiarini H.G. Balda J.C. 《Power Electronics, IEEE Transactions on》2008,23(2):581-590
This paper proposes a novel method to generate a sinusoidal waveform synchronized with any measurable periodic signal whose frequency is within a given neighborhood. The synthesized sinusoidal signal could be used as a reference current for certain applications of parallel active power filters or any other where such synchronization would be necessary (e.g., ac/dc converters for renewable energy resources, power factor correctors, power supplies, UPS, etc.) The method is based on the behavior of a dynamical system and avoids employing the usual combination of phase-locked loop (PLL) and lookup table found in most parallel active filters synthesizing a sinusoidal source current (a table also means using significant storage memory). The novel method produces two high-quality sinusoidal waveforms that are in quadrature and is applicable to those parallel active filters whose control methodology is in the reference frame, or alternatively, it produces three sinusoidal waveforms shifted 120 degrees for designs that work in the frame. Here, a th order implementation is described, including a proof of convergence. For its most simple implementation , simulated and experimental results are included. 相似文献
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Vazquez N. Aguilar C. Arau J. Caceres R.O. Barbi I. Gallegos J.A. 《Power Electronics, IEEE Transactions on》2002,17(3):405-412
This paper presents a simplified sinusoidal uninterruptible power supply (UPS) system. The proposed scheme includes features such as high power factor, low total harmonic distortion and good dynamic response at the AC output voltage. In addition, the scheme has the desirable characteristics, of high efficiency, simple circuit and low cost compared with a traditional standalone multiple stages UPS with power factor correction. The paper also presents the circuit operation, the analysis and, experimental results of the proposed UPS scheme. The proposed UPS approach is a good solution in low. power applications (⩽500 W) 相似文献
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《Industrial Electronics, IEEE Transactions on》2008,55(8):2943-2953
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瞬时值反馈型正弦波逆变器因其对非线性负载适应能力强,受到应用者的关注,是有前景的一种逆变器控制方式,但其控制器设计方法尚不如直流控制系统的控制器成熟,是当前急需解决的一个应用问题。文章首先针对线性时不变交流反馈控制系统的特点,讨论了直流控制系统的调节器不能直接用于交流控制系统的原因,然后给出了适用于线性时不变交流控制系统的交流调节器设计方法,以一个瞬时值反馈正弦波逆变器的控制回路设计问题为例进行了应用性研究,取得了预期的结果。 相似文献
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为有效保证不问断电源逆变器交直流切换过程不对负载产生过大的冲击,UPS逆变输出电压必须与电网电压的频率及相位保持一致。快速可靠的软件锁相跟踪技术可以准确地为逆变器数字化控制提供与电网电压同频同相的标准正弦电压。本文主要讨论基于TMS320LF2407数字化控制平台的全数字不间断电源中的锁相控制技术。 相似文献
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Eung-Ho Kim Jung-Min Kwon Jae-Kyu Park Bong-Hwan Kwon 《Industrial Electronics, IEEE Transactions on》2008,55(8):2933-2942
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Tzuen-Lih Chern Chang J. Chien-Hung Chen Hann-Tzong Su 《Industrial Electronics, IEEE Transactions on》1999,46(2):340-348
This paper presents a digital signal processor microprocessor-based high-performance uninterruptible power system (UPS). It also modifies the integral variable-structure control (IVSC) approach to be more suitable for the UPS, which is tracking a sinusoidal AC voltage with specified frequency and amplitude. Since the implementation of the control laws has tended to the digital microprocessor, the paper extends the modified IVSC to the discrete time domain. Procedures are developed for determining the control function, the switching plane and the integral control gain, so that the system has desired properties. Simulation and experimental results show that the proposed scheme can supply a high-quality voltage power source in the presence of load disturbance and parameter variation 相似文献
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This paper presents the analysis and design of a multiple feedback loop control scheme for single-phase voltage-source uninterruptible power supply (UPS) inverters with an L-C filter. The control scheme is based on sensing the current in the capacitor of the load filter and using it in an inner feedback loop. An outer voltage feedback loop is also incorporated to ensure that the load voltage is sinusoidal and well regulated. A general state-space averaged model of the UPS system is first derived and used to establish the steady-steady quiescent point. A linearized small signal dynamic model is then developed from the system general model using perturbation and small-signal approximation. The linearized system model is employed to examine the incremental dynamics of the power circuit and select appropriate feedback variables for stable operation of the closed-loop UPS system. Experimental verification of a laboratory model of the UPS system under the proposed closed-loop operation is provided for both linear and nonlinear loads. It is shown that the control scheme offers improved performance measures over existing schemes, It is simple to implement and capable of producing nearly perfect sinusoidal load voltage waveform at moderate switching frequency and reasonable size of filter parameters. Furthermore, the scheme has excellent dynamic response and high voltage utilization of the DC source 相似文献
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关于UPS‘Delta变换技术''的讨论 总被引:1,自引:0,他引:1
“Delta变换技术”是近年来在UPS中使用的新技术,而应用“Delta变换技术”的UPS产品也已经推向市场。本文从“Delta变换技术”的技术属性、应用该技术的UPS主电路结构及其PFC功能、在线式工作功能等方面对它作了较详尽的介绍。 相似文献
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Combination voltage-controlled and current-controlled PWM invertersfor UPS parallel operation 总被引:1,自引:0,他引:1
Jiann-Fuh Chen Ching-Lung Chu 《Power Electronics, IEEE Transactions on》1995,10(5):547-558
In this paper, a scheme of combination of voltage-controlled and current-controlled PWM inverters for parallel operation of a single-phase uninterruptible power supply (UPS) is proposed. The voltage-controlled PWM inverter (VCPI) unit as a master is developed to keep a constant sinusoidal wave output voltage. The current-controlled PWM inverter (CCPI) units are operated as slave controlled to track the distributive current. The power distribution center (PDC) performs the function of distributing the output current of each active unit. In this proposed scheme of parallel operation, each of the units can be designed as nearly independent, and the CCPI units do not need a PLL circuit for synchronization. As a result, the parallel operation of UPS is easy to implement and to expand system capacity. For the purpose of illustration, the system, including three single-phase units which operate in parallel, is analyzed and experimental results are given 相似文献
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Distributed Control for UPS Modules in Parallel Operation With RMS Voltage Regulation 总被引:1,自引:0,他引:1
Zhongyi He Yan Xing 《Industrial Electronics, IEEE Transactions on》2008,55(8):2860-2869
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对在线式正弦波输出UPS、后备式正弦波输出UPS、后备式方波输出UPS电源的主要特点进行了介绍,指出在选购UPS电源时应着重考虑的几个因素,并对UPS电源的日常维护提出了几点建议。 相似文献
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赵黎明 《电信工程技术与标准化》2005,(5):31-35
本文阐述了UPS招标文件中输入电流谐波成份和输入功率因数两项指标的重要性,指出常用的双变换在线式UPS提高输入功率因数及降低输入电流谐波成份的解决方法. 相似文献
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S.-S. Kwak 《International Journal of Electronics》2013,100(5):636-645
A three-phase-to-two-phase ac–ac converter is, along with a modulation strategy based on the space vector scheme, introduced to directly drive two-phase output ac systems with high input power quality. The converter is capable of synthesising two sinusoidal output voltages with variable output frequency and arbitrary magnitude in quadrature phase-shift as well as sinusoidal input currents. 相似文献