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1.
High power factor AC/DC/AC converter with random PWM 总被引:1,自引:0,他引:1
Bor-Ren Lin 《IEEE transactions on aerospace and electronic systems》1999,35(3):935-943
A three-phase AC/DC/AC converter is presented with a power factor preregulator to improve the power quality in the input side and a pseudorandom noise generator to reduce the emitted acoustic noise and the mechanical vibration for an induction motor drive. The space vector modulation with hysteresis current control for a voltage source rectifier is adopted to simplify the hardware circuit. A control scheme is presented to drive the supply current following the reference current. The amplitude of reference current for the pulsewidth modulation (PWM) rectifier is derived from the DC bus voltage regulator and the estimated output power. Random switching frequency technique for a three-phase PWM inverter system to reduce the annoying tonal noise and resonant vibration from an induction motor is described. By randomly varying the instantaneous PWM switching frequency from one cycle to the next, the frequency distribution of harmonics is spread in a wide frequency range. The major advantage for using such a strategy is the nonrepetitive output spectral characteristic that results in reduction of torque pulsations in motor drive systems. The nearly unity power factor at the three-phase rectifier and the absence of acoustic noise concentrated at the specific tones which is usually present with conventional sinusoidal modulation are verified by the experimental tests 相似文献
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Three pulse-width modulation (PWM) control schemes for a single-phase power-factor-correction (PFC) AC/DC converter are presented to improve the power quality. A diode bridge with two power switches is employed as a PFC circuit to achieve a high power factor and low line current harmonic distortion. The control schemes are based on look-up tables with hysteresis current controller (HCC) to generate two-level or three-level PWM on the DC side of diode rectifier. Based on the proposed three control schemes, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage, and two capacitor voltages on the DC bus are controlled to be balanced. The simulation and experimental results of a 1 kW converter with load as well as line voltage variation and shown to verify the proposed control schemes. It is shown that unity PFC is achieved using a simple control circuit and the measured line current harmonics satisfy the IEC 1000-3-2 requirements 相似文献
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A single-phase ac/ac converter based on neutral-point-clamped scheme is proposed to perform unity input power factor and to provide a stable ac voltage to the critical loads. The ac/dc rectifier part is controlled to generate a unipolar pulsewidth modulation (PWM) waveform on the ac terminal by using four power switches with voltage stress of half the dc-link voltage. The carrier-based current control scheme is employed in the inner control loop to track the line current command. To regulate the dc bus voltage, a proportional-integral (PI) control is adopted in the outer control loop. The dc/ac inverter part of the system with four power switches is employed to generate a stable and clean sinusoidal output voltage to the critical load. The instantaneous current control scheme is used to track the output voltage command. To verify the effectiveness of the proposed control algorithm, the simulation and experimental results based on a laboratory prototype were implemented and discussed. 相似文献
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Ying-Yu Tzou Shih-Liang Jung 《IEEE transactions on aerospace and electronic systems》1998,34(4):1218-1226
The design and implement action of a DSP-based fully digital-controlled single-phase pulsewidth modulated (PWM) dc-ac converter for ac voltage regulation is described. The proposed multiloop digital controller (MDC) consists of a current controller, a voltage controller, and a feedforward controller. This MDC was realized using a single-chip digital signal processor (DSP). The PWM gating signals are determined at every sampling instant by the proposed multiloop digital control scheme using a set of detected feedback signals. A software current control; scheme has been developed to achieve fast current control of the PWM inverter and decouple the inductor of the output filter. Experimental results have been given to verify the proposed digital control scheme. The constructed DSP-based PWM dc-ac converter system can achieve fast dynamic response and with low total harmonic distortion (THD) for rectifier type of loads 相似文献
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Jain P. Tanju M.C. Bottrill J. 《IEEE transactions on aerospace and electronic systems》1993,29(2):425-434
A new class of AC/DC converter topologies (Type-1 converters) is described, suitable for use in an advanced single-phase sine-wave voltage, high-frequency power distribution system, of the type that was proposed for a 20 kHz Space Station primary electrical power distribution system. The converter comprises a transformer, a resonant network, a current controller, a diode rectifier, and an output filter. The input AC voltage source is converted into a sinusoidal current source using the resonant network. The output of this current source is rectified by the diode rectifier and is controlled by the current controller. The controlled rectified current is then filtered by the output filter to obtain a constant voltage across the load. Three distinct converter topologies, Type-1A, Type-1B, and Type 1-C, are described, and their performance characteristics are presented. All three types have a close-to-unity rated power factor (greater than 0.98), low total harmonic distortion in input current (less than 5%), and high conversion efficiency (greater than 96%) 相似文献
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针对航空发动机全权限数字电子控制(FADEC)系统专用发电机的输出特性,提出一种电流回馈型恒流变频AC/DC(交流/直流)变换技术,以适应专用发电机的宽输出范围,满足FADEC系统的供电需求.给出了该技术的控制策略、拓扑结构、工作原理、过压故障检测及保护设计方法.试验结果表明:该变换器工作稳定,在-55~125℃全温范围内,满足国家军用标准飞机供电特性(GJB181A)对电源的相关规定.研究成果已成功应用于某型航空发动机数字控制系统中,并通过了台架试车和飞行平台试验. 相似文献
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A pulsewidth-modulated (PWM) zero-voltage-switching quasi-resonant boost converter operating at constant switching frequency is presented. In contrast to the frequency-modulated (FM) zero-voltage-switching quasi-resonant boost converter, this converter possesses better controllability and higher operating performance, and overcomes the instability caused by the parasitic oscillation. The principle of operation and performance of the converter are presented. Its two-dimensional state trajectories and steady-state characteristic curves are derived which are useful for the converter design. Both the SPICE simulation and experimental result agree with the theoretical prediction 相似文献
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Reaction flywheel is a significant actuator for satellites’ attitude control. To improve output torque and rotational speed accuracy for reaction flywheel, this paper reviews the modeling and control approaches of DC-DC converters and presents an application of the variable structure system theory with associated sliding regimes. Firstly, the topology of reaction flywheel is constructed. The small signal linearization process for a buck converter is illustrated. Then, based on the state averaging models and reaching qualification expressed by the Lee derivative, the general results of the sliding mode control (SMC) are analyzed. The analytical equivalent control laws for reaction flywheel are deduced detailedly by selecting various sliding surfaces at electromotion, energy consumption braking, reverse connection braking stages. Finally, numerical and experimental examples are presented for illustrative purposes. The results demonstrate that favorable agreement is established between the simulations and experiments. The proposed control strategy achieves preferable rotational speed regulation, strong rejection of modest disturbances, and high-precision output torque and rotational speed tracking abilities. 相似文献
9.
Moschopoulos G. Mei Qiu Pinheiro H. Jain P. 《IEEE transactions on aerospace and electronic systems》2003,39(2):660-674
A pulsewidth modulated (PWM) full-bridge converter that simultaneously performs input power factor correction (PFC) and DC-DC conversion is proposed. The converter is the same as the standard voltage-fed PWM full-bridge converter with a diode-bridge low-pass filter front end, but with a slight modification that results in an improvement in power factor that is sufficient to satisfy the EN61000-3-2 requirements for electrical equipment. The operation of the converter is explained and analyzed, and the results of the analysis are used to determine the converter's steady-state characteristics, which are discussed in detail. A design procedure for the selection of components is then derived and demonstrated with an example. The feasibility of the converter and its ability to satisfy EN61000-3-2 requirements on electrical equipment is shown with results obtained from an experimental prototype. 相似文献
10.
《中国航空学报》2023,36(7):420-429
In this paper, a fault-tolerance wide voltage conversion gain DC/DC converter for More Electric Aircraft (MEA) is proposed. The proposed converter consists of a basic Cuk converter module and n expandable units. By adjusting the operation state of the expandable units, the voltage conversion gain of the proposed converter could be regulated, which makes it available for wide voltage conversion applications. Especially, since mutual redundancy can be realized between the basic Cuk converter module and the expandable units, the converter can continuously work when an unpredictable fault occurs to the fault-tolerant parts of the proposed converter, which reflects the fault tolerance of the converter and significantly improves the reliability of the system. Moreover, the advantages of small input current ripple, automatic current sharing and low voltage stress are also integrated in this converter. The working principle and features of the proposed converter are mainly introduced, and an experimental prototype with 800 W output power has been manufactured to verify the practicability and availability of the proposed converter. 相似文献
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A buck converter operating at constant switching frequency, whose active switches and recovery diode commutate at zero-voltage-switching (ZVS), with zero capacitive turn-on losses, is proposed. By using the parasitic capacitances of the switches as resonant capacitors, multiresonance is created. The resonant stage takes place only after the resonant inductor has been discharged, thus avoiding a resonant current peak; the devices are subjected to the same stresses as their counterparts in conventional hard-switching converters. A high efficiency is obtained. 相似文献
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A DC/AC interface inverter for a high-frequency space power distribution system that uses dual asymmetrical resonant bridges is examined. Compared to the conventional approach in which two symmetrical bridges are used, the asymmetrical bridges arrangement offers better use of the installed kVA rating and efficiency of the inverter system. A simplified approach for modeling the inverter system in steady-state is presented, and a criteria to select the resonant components is given. A detailed simulation is performed for the following: a symmetrical inverter system with a resistive load, an asymmetrical inverter system with a resistive load, and an asymmetrical inverter system with the type-1A AC/DC converter load 相似文献
14.
Huai Wei Batarseh I. Kornetzky P. 《IEEE transactions on aerospace and electronic systems》1999,35(4):1344-1353
A new single-stage single-switch power factor correction converter with output electrical isolation is presented. The configuration of this converter is achieved by combining a flyback circuit and a forward circuit in one power stage. The principle of operation and steady-state analysis of the proposed topology is given. Based on its steady-state operation constraints, a design procedure along with a specific design example is reported. To verify the theoretical analysis of the proposed converter, a design example is given with its PSPICE simulation and experimental results 相似文献
15.
Jalade J. Marpinard J.C. Valentin M. 《IEEE transactions on aerospace and electronic systems》1981,(3):373-379
A new generation of dc/ac sine generators, based on dc/dc, pulse-width modulation (PWM) storage converter structure operating with rectified sine wave control and associated with a controlled bridge, is described. The efficiency, harmonic distortion, and transien't behavior are better in dc/dc sine convertors than conventional dc/ac sine convertors. Continuous non-linear or linear methods previously described can be extended to design this structure. 相似文献
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根据空气/煤油富油燃烧的特点,提出了两种空气/煤油燃气发生器富油燃烧组织方案,设计了采用钝体稳定火焰和旋流空气、二次喷注空气稳定火焰的两种燃气发生器.为了对比两种方案的点火和燃烧特性,对两种燃气发生器进行了一系列热试,结果表明余氧系数是燃气发生器最重要的工况参数.随着余氧系数的增加,燃气发生器的状态逐渐从启动失败变为中途熄火,最终呈正常启动状态.采用钝体稳定火焰的燃气发生器稳定工作的余氧系数边界为0.518,采用旋流空气和二次喷注空气稳定火焰可将该边界延伸到0.237,极大地扩大了燃气发生器的工作范围.与钝体稳定火焰的燃气发生器相比,旋流空气和二次喷注空气稳定火焰的燃气发生器的富油燃烧的燃烧效率提高了20%.两种方案结构复杂性相当,旋流空气和二次喷注空气稳定火焰的燃气发生器不需要冷却火焰稳定器,可提高燃气发生器的工作时间. 相似文献
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Kenny B.H. Jansen R. Kascak P. Dever T. Santiago W. 《IEEE transactions on aerospace and electronic systems》2005,41(4):1431-1449
Energy storage and attitude control are two distinct subsystems of the typical satellite. Energy storage is provided using batteries and active attitude control is accomplished with control moment gyroscopes or reaction wheels. A system mass savings can be achieved if these two subsystems are combined using multiple flywheels for simultaneous kinetic energy storage and momentum transfer. This paper develops, simulates, and experimentally demonstrates the control algorithms to accomplish integrated power and single-axis attitude control using two flywheels. 相似文献