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1.
安全性、可靠牲和功率因数校正是首先要考虑的问题  相似文献   

2.
使用开关电源供电,设计了电力测控装置高速高精度模数转换电路,提出了抗干扰措施,讨论了电路设计和优化方案.测试结果表明,开关电源加上后置滤波以及电路精心的设计和布局、布线,可以成为为高速ADC供电的高效率解决方案.  相似文献   

3.
This paper proposes a robust three-phase active power-factor-correction (PFC) and harmonic reduction scheme suitable for higher power applications. The proposed system is a unique combination of a low-kilovoltampere 12-pulse rectifier system with a single-phase boost PFC scheme to shape the input current to near sinusoidal waveshape. The voltampere rating of the active PFC converter is 0.05 pu and is not exposed to line transients under varying load conditions. The proposed system is suitable for utility interface of higher power rectifiers employed in power supplies and adjustable-speed drive systems which demand clean input power characteristics in the range of 1-500 kW. The proposed system is rugged and, in the event the active control were to fail, the system reverts to 12-pulse operation with fifth and seventh harmonic cancellation. Analysis and design of the system is examined in detail, and simulation and experimental results on a 10 kVA prototype are shown  相似文献   

4.
《UPS应用》2007,(2):20-24
为了便于我国电源技术工作者编写技术文件或阅读科技图书刊物,这里刊出下述标准供学习参用。如需引用,请查阅标准原件。  相似文献   

5.
Multilevel inverter (MLI) generates stepped voltage with appropriate switching combination of power devices, thus restraining the requirement of filter circuit for an efficient power conversion. MLIs are attracting due to some of the major features like economic cost, installation space, bulkiness, complexity along with its enormous applications in industries like cement factory, ceramic industry, aerospace applications etc. In this paper, a single-phase generalised inverter based on five different algorithms is proposed that uses the minimum of overall power components. The presented topology can be used in low and medium voltage applications. To verify the simulation results obtained by MATLAB/Simulink, DS1103 controller is used to generate the corresponding experimental results by developing a prototype model in the laboratory. Nevertheless, a comparative assessment for the different required components of the proposed topology is carried out with some recently developed topologies. Reduction in power switches, driver circuits and DC voltage sources reduces the size, cost, complexity and enhances the overall performance. In addition, level per switch ratio is added in this paper to decide the effectiveness of the proposed topology.  相似文献   

6.
The use of magnetoresistors, which are being developed in this laboratory for practical uses, such as regulation of power supplies and magnetic fields, is discussed.  相似文献   

7.
This paper reviews data from the International Technology Roadmap for Semiconductors to establish where dc-dc converters are headed in the first decade of the new millennium. It focuses on the high performance computing (high current, fast response, high power density) and portable/handheld (low profile) sectors. Magnetics and power device packaging technologies needed to allow power supplies to move to operating frequencies in the 1-10 MHz region are discussed. It introduces the concept of magnetic components fully embedded (windings and core) in PCB and silicon offering low profile and low losses at high frequency. It also reviews developments in wirebond-free power packaging such as flip-chip assembly that offer low profile, reduced parasitics and increased thermal performance. Finally, consideration is given to the changes in the power electronics industry that may need to be addressed to enable these new technologies to play a strategic role.  相似文献   

8.
This paper develops a method for simultaneously designing the power stage and controller for a switching power supply. The method utilizes a numerical optimization procedure, which facilitates computer-aided design. It is found that better performance can be achieved than with a traditional two-step design process, where the power stage and controller are designed sequentially. Optimization and simulation results for a buck power converter are presented to illustrate the design process and benefits  相似文献   

9.
Single-stage isolated power-factor-corrected power supplies (SSIPP) have the attractive features of fast regulation and a single control loop. However, SSIPP circuits also have higher voltage stress and heavier loss (when compared with a normal DC-DC power converter), which severely limit their practical applications. In this paper, the authors propose to add active clamping to SSIPP to recycle the energy trapped in the leakage inductance of their transformer (to keep the switch voltage stress low) and to achieve soft switching of their electronic devices (to further reduce the loss). This arrangement significantly improves the viability of SSIPP for practical applications. The auxiliary active-clamping transistor in the proposed circuit uses the same control/driver circuit as the main switching transistor. Simulations and experimental works verifying the operation of the converter are reported  相似文献   

10.
Analysis of the newly discovered mixed-mode EMI noises provides a better understanding of the filter attenuation mechanism. Many practical design issues are investigated from this point of view. Hopefully, the results given in the paper reduce the mystery and the cut-and-try process in filter design in offline power supplies  相似文献   

11.
The authors present an electrical design inspection (EDI) methodology that combines advanced power circuit simulation techniques and RISC (reduced instruction set computing) workstation hardware to use simulation in the day-to-day design of electronic power supplies. This methodology makes use of circuit simulation to detect design faults in electronic power supplies and prevent them from propagating further in the product realization process. A hierarchy of inspections which form the basis of EDI methodology, is introduced. The methodology has been embedded in a prototype electrical design inspection system which has been tested on a Sun Sparcserver 4/490 dedicated to circuit simulation. The power of this methodology has been illustrated by its application to a self-oscillating variable-frequency DC-DC power converter with peak current control. It is demonstrated that EDIS can automatically execute inspections requiring an accurate determination of the steady-state solution of the circuit, and process these results. The steady-state accelerator capability within the SIMPLIS circuit simulator has made it possible to achieve this in an unprecedentedly short CPU time  相似文献   

12.
A new bandgap current reference is described which can be used to control the injector current of I/SUP 2/L circuits for supply voltages down to about 1 V. For small currents the total injector current is obtained as a mirror of the reference current. For large injector currents the current control is performed by a series regulator which compares the injector current of one I/SUP 2/L gate to the reference current. The described reference current can be adjusted to give a variation with temperature of about 60 ppm//spl deg/C over the temperature range -10 to +70/spl deg/C. However, in some applications a nonzero, but well controlled temperature coefficient is desired. It is shown how a temperature stable ring oscillator with I/SUP 2/L gates can be constructed by tailoring the temperature dependence of the supply current appropriately.  相似文献   

13.
Silicon-controlled-rectifier (SCR) power supplies employing capacitor input filters cause large-pulse line currents. Usually the associated transformer is designed to have a minimal amount of leakage inductance. This paper studies such a system and concludes that there is an optimum value of leakage inductance that minimizes the line current and the transformer size. SCR and capacitor currents are also reduced. Design equations and curves are included.  相似文献   

14.
A control scheme is proposed that employs an active rectifier to work simultaneously as an active power filter to decrease current harmonics. The adopted capacitor clamped rectifier is controlled to draw a sine wave line current with low current harmonics. A voltage controller, three capacitor voltage compensators and one current controller are used in the proposed control algorithm to achieve a constant DC bus voltage, balanced capacitor voltages and line current tracking. The validity of the proposed system is proved by the results of computer simulations and experimental tests.  相似文献   

15.
This paper presents a new, online, battery state-of-charge estimation and monitoring system for both the discharge and charge periods of sealed lead-acid batteries, commonly used in telecommunication power systems as backup power supplies. The proposed monitoring system is based on discharge time versus discharge rate data given in manufacturers' data sheets, and coulometric measurements, without the need for any battery voltage measurement under open-circuit conditions. The corresponding battery management system can perform both the online monitoring and battery charging tasks by the use of the same low-cost 8-bit microcontroller. Battery state-of-charge monitoring tests have been carried out under both constant and dynamic load conditions and for alternate charge-discharge cycles of lead-acid batteries of different capacities, and for different operating temperatures. The test results have shown that a very good accuracy (better than 3%-4%) in the estimation of available capacity is obtained for various charge-discharge strategies corresponding to practical operating conditions. Changes in battery characteristics which occur due to aging are also taken into account by estimating the actual capacity of the battery and adopting the corresponding recharacterization of the aged cells automatically.  相似文献   

16.
本文提出了一种应用于双通道卫星导航接收机的高效率低噪声电源解决方案,主要包括降压型DC-DC转换器和低压差稳压器。为了获得更好的噪声抑制和抗干扰性能,应用脉冲宽度调制(PWM)作为DC-DC转换器的控制方式。提出了一种改进的低功耗PWM控制电路,通过周期性的关断跨导放大器,将转换器的平均静态功耗降低了一半,并且具有较高的工作频率。针对双通道接收机的特点,对输出级功率管的尺寸进行了优化,使效率最优。另外,提出了一种基于限流原理的新型软启动电路,无须使用片外大电容或数模转换器,降低了设计复杂度。电路使用180nm CMOS工艺流片,测试结果显示,DC-DC转换器在2MHz的工作频率下拥有最高93.1%的转换效率,整个双通道接收机在3.3V电源供电下仅消耗电流20.2mA。  相似文献   

17.
A high-efficiency low-noise power solution for a dual-channel GNSS RF receiver is presented.The power solution involves a DC-DC buck converter and a followed low-dropout regulator(LDO).The pulsewidth -modulation(PWM) control method is adopted for better noise performance.An improved low-power highfrequency PWM control circuit is proposed,which halves the average quiescent current of the buck converter to 80μA by periodically shutting down the OTA.The size of the output stage has also been optimized to achieve high efficiency under a light load condition.In addition,a novel soft-start circuit based on a current limiter has been implemented to avoid inrush current.Fabricated with commercial 180-nm CMOS technology,the DC-DC converter achieves a peak efficiency of 93.1%under a 2 MHz working frequency.The whole receiver consumes only 20.2 mA from a 3.3 V power supply and has a noise figure of 2.5 dB.  相似文献   

18.
Since many years the calibration of test equipments is one of the main tasks in the technology of length measurement. Through the reduction of tolerances within the manufacturing process the request for high quality of the measuring instruments and test procedures rises. The classification of test equipments depends on the roughness and the deviation of size, form and position. During the tests we analysed plug gauges and ring gauges whose size was changed in phases. The aptitude of test procedures with 2D- or 3D-measuring instruments can be identified with the help of the developed software.  相似文献   

19.
The complete problem, to minimize the operating cost of a hydrothermal generation system over one day (or one week) is formulated and solved through a few assumptions: the dc approximation and a linear law for the fuel costs, primarily the methods used mix the combinatorial and the electrical features of the problem. New methods employed are a branch and bound method for the thermal unit commitment, a gradient method to set the hydropower, and an economic dispatch routine with active flow constraints.  相似文献   

20.
A gradual degradation has been observed in the RF performance of GaAs power FETs. Electrical and physical analyses have been carried out, indicating the role played by the surface. A plasma enhanced chemical vapour deposited silicon nitride film is established as a suitable surface passivation.  相似文献   

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