A new design of power supplies for pocket computer systems

A new design of power supply based on the idea of switched capacitors, as applied to pocket computer systems, is presented. This new type of power supply is inductorless and, consequently, suitable for hybridization and even monolithic integration. The new design is also based on distinguishing characteristics of pocket digital computer systems, in which a switched-capacitor converter can work well, since minimal regulation is required. The new device may enable the pocket computer system to be powered by only one battery, resulting in a simple topology. Two switched-capacitor converters, +12 V/-12 V, +5 V and +5 V/+12 V, -12 V, are shown, respectively, as an example for demonstrating the basic principle and its performance. PSPICE simulation and laboratory models show good results for this new type of power supply     

电力传动系统的转矩控制器优化设计与实现

恶劣环境下的电力传动系统中的转速传感器会出现故障,导致在低速运行情况下受到低开关频率限制,此时采用传统直接转矩控制系统,从单点出发搜索最佳电机参数控制点,存在较高的转矩脉动。因此,提出基于改进遗传禁忌算法设计的转矩控制器,该控制器通过基于DSP的转矩控制系统控制电机的转矩以及转速和转角,基于改进遗传禁忌算法控制方案给出转矩控制指令,实现电力传动系统转矩的精确控制。速度调控器采用改进遗传禁忌算法的PID控制器,完善电力传动系统的转矩控制性能。将禁忌搜索方法当成遗传算法的变异算子,避免电力传动转矩控制系统中PID速度调控器出现超调问题,使得低速运行情况下转矩控制器保持平稳的转矩脉动,增强电力传动系统的稳定性。实验结果说明,该方法能够有效优化电力传动系统的转矩性能,获取平稳的转矩波形。     

电源用电容器的选择

电容器是实现电源的宽范围电压和电流组合的最关键的无源元件之一。尽管每种电容器都能储存电能，但对于特定的应用来说，电介质技术在电容器的选择中起着重要的作用。电容器在电源中最重要的应用是在存储能量、浪涌电压保护、EMI抑制和控制电路等方面。我们可以通过图1了解到针对不同的应用领域，这些电介质技术彼此竞争或互为补充的关系。储能储能型电容器通过整流器收集电荷，并将存储的能量通过变换器引线传送至电源的输出端。电压额定值为40～450Vdc、电容值在220～150 000μF之间的铝电解电容器（如EPCOS公司的B43504或B43505）…     

Observer-based robust controller design and realization of a gantry stage

A precise positioning operation is typically required for gantry systems in applications such as drop-on-demand (DOD) printing processes, precision metrology, and circuit assembly. This work presents experimental results from studies of a disturbance observer (DOB) based variable structure controller (VSC) for a gantry stage. For DOB-based controllers, a nominal model is needed; however, obtaining the nominal model is difficult for systems with friction. A pseudo-random binary signal (PRBS) is utilized to identify the linear nominal model of the gantry stage with friction. To compensate for friction effects, a filtered-VSC is studied to increase robustness and compensate for modeling uncertainties and external disturbances. Experimental results demonstrate the effectiveness of the proposed robust control structure.     

射频CO2激光器实用功率控制器的设计

随着工业技术的现代化 ,对CO2 激光器的整体性能和技术参数方面都提出了越来越苛刻的要求 ,如寿命 ,机械性能和光束质量等 .这就要求激光器使用前要确保其性能的可靠性 ,其中激光器的开关次数和连续工作时间是影响其性能的关键因素 ,本文主要介绍一种测试激光器性能用的功率控制器 ,它不仅具有通常功率控制器的功能 ,还带有自动开关功能 ,并且简单实用     

Power controller design for maximum power tracking in solar installations

A state space approach to the design of a maximum power point (MPP) tracking system for photovoltaic energy conversion is presented. The problem of optimal-power control of a nonlinear time-varying system is reduced to an ordinary problem of dynamic system stability in state space by applying MPP conditions in controller design. The resulting tracking system searches for the reference point and tunes the converter for maximum power delivery to a load that may represent an end-user, or an energy-storage element, or a power grid-interface. The proposed design procedure for the MPP tracking system ensures a global asymptotic stability under certain conditions, and a minimum degree of the dynamic feedback. The design is verified using the virtual test bed, demonstrating accurate MPP tracking capability under unpredictable weather change, parameter variation, and load disturbance. The tracking system can be applied either to a stand-alone or grid-connected photovoltaic installations, and can be implemented in either analog circuitry or a digital microcontroller.     

Small-signal analysis and control design of isolated power supplies with optocoupler feedback

Optocouplers are widely used in isolated power supplies to transfer the feedback signal from the secondary to the primary side. In many power supplies, the feedback amplifier is supplied from the output voltage that creates additional feedback path which should be taken into account in the control design. The paper presents a detailed analysis and control design for each of the two possible feedback loops that can be identified. In addition, dynamic limitations of the TL431 shunt regulator and of the optocoupler are discussed. Practical guidelines for the error amplifier design and a design example are presented for both voltage-mode and current-mode controls.     

Electrical design inspection: a methodology for using circuitsimulation in the design and development of electronic power supplies

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     

台式电源设备

精确、稳定的电源 为办公室应用设计的Z系列可编程电源通过RS-232、RS-485、GPIB控制,配置31种直流输出。该电源可直接与计算机接口相连,相同的单元可并联组成主从配置,对大功率需求自动共享电流。 该电源有200、400和800W三种型号,输出电压     

High performance predictive dead-beat digital controller for DCpower supplies

In this paper, a digital control technique based on a two-loop predictive dead-beat control concept is developed for switchmode DC/DC power supply applications. The dead-beat control law is derived directly from the switching characteristic of the converter. With the inductor current reaching the reference in a single control period, the proposed technique results in much improved control performance. In addition, the design procedure is simple and does not require extensive tuning. Furthermore, the computational resources required for the calculation of the control algorithm are reduced by half as compared to a conventional digitized PI structure. Both experimental and simulated results are provided to validate the proposed concept     

PoE用电设备电源评估

由于受以太网技术向各类市场的扩展、以及IP电话与2003年采纳IEEE 802．3af标准等因素的推动,以太网供电(PoE)市场正在快速扩大。从以太网线上获得电源的设备称为用电设备(powered device),简称PD。     

汽车照明电源设计

汽车中大多采用LED和CCFL作为背光源,两种方案均需要特殊的供电电源.设计了LED、CCFL灯源的供电方案,并给出汽车内部照明、背景显示以及外部照明等多种具体的应用电路,可用于汽车的内部和外部照明领域.这些汽车照明电源应用设计电路能够有效散热,并极大节省设计成本.     

A novel design of line-interactive uninterruptible power supplies without load current sensors

In this paper, a new approach for the design of line interactive uninterruptible power supplies (UPS) without load current sensors is proposed. Based on the interactive structure, this system is constructed that includes the power factor improvement capability in anticipation of increasing the quality of supplying power. With the employment of such an approach, the power converter can be adaptively operated at the active power filter mode or backup mode, by which the power can be supplied to the connected load very reliably. Moreover, as the proposed circuit needs only one current feedback signal where the load current sensors can be saved, the circuit design can be thus simplified significantly. In order to confirm the effectiveness of this proposed design, the approach has been tested through the theoretical analysis and experimental validation under different test scenarios. Test results help support the feasibility and practicality of the method for the application considered.     

Mixed-mode EMI noise and its implications to filter design inoffline switching power supplies

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     

Magnetoresistors for regulation of power supplies and magnetic fields

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.     

满足开关电源要求的功率MOSFET

近年来,电源的输出电压越来越低、输出电流越来越大(某些电源系统输出几十安培到上百安培).因此,电源设计中采用开关电源控制器、加上多个驱动器及功率MOSFET组成的多相开关电源能满足这种要求.     

Electronic prognostics for switched mode power supplies

Switching power supplies have become ubiquitous in electronic modules and systems. From converting power types, power levels, or driving actuators, these power converters embody varying topologies but usually have high switching rates of up to 500 KHz, power devices such as MOSFETs, microelectronic components and a mix of passive components that store and release energy. They are complex modules that have an unfortunate history of observed high failure rates, yet they may be required to support critical systems.Electronic prognostics/health management, or ePHM, provides the ability to predict the failure of the electronic before it actually occurs. This paper will examine the considerations associated with key system- and device level prognostics that designers need to evaluate when “PHM-enabling” their power system.     

高压电源抗干扰技术

高压开关电源易受干扰而造成直通,针对这种缺陷,本文提出了一种简单而有效的抗干扰方法,原电路只增加少量元器件就可彻底消除直通故障。     

Experimental design of a fuzzy controller for improving power factor of boost rectifier

This article presents the design and the implementation of dSPACE DS1104 controller board-based PI and fuzzy logic peak current-mode controllers in the voltage loop and two controllers in the current loop based first on a standard fixed hysteresis band control, followed by a variable hysteresis band control to achieve constant switching frequency for a single-phase active power factor corrector in the continuous conduction mode. All these controllers have been verified via simulation in Simulink and a real-time implementation is performed on an experimental test bench utilising a rapid prototyping tool. The controllers are experimentally compared for steady-state performance and transient response. It is shown that the PI and fuzzy logic controllers give a superior steady-state performance, whereas the fuzzy logic inference based controller can achieve better dynamic response than its PI counterpart under large load disturbance and plant uncertainties. Furthermore, the variable hysteresis band control in the current loop gives a low total harmonic distortion of the input current compared to a standard fixed hysteresis band control.     

Packaging and integration technologies for future high-frequency power supplies

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.