A Digital Current-Mode Control Technique for DC–DC Converters

The objective of this paper is to propose a simple digital current mode control technique for dc-dc converters. In the proposed current-mode control method, the inductor current is sampled only once in a switching period. A compensating ramp is used in the modulator to determine the switching instant. The slope of the compensating ramp is determined analytically from the steady-state stability condition. The proposed digital current-mode control is not predictive, therefore the trajectory of the inductor current during the switching period is not estimated in this method, and as a result the computational burden on the digital controller is significantly reduced. It therefore effectively increases the maximum switching frequency of the converter when a particular digital signal processor is used to implement the control algorithm. It is shown that the proposed digital method is versatile enough to implement any one of the average, peak, and valley current mode controls by adjustment of the sampling instant of the inductor current with respect to the turn-on instant of the switch. The proposed digital current-mode control algorithm is tested on a 12-V input and 1.5-V, 7-A output buck converter switched at 100kHz and experimental results are presented     

电流型Buck-Boost变换器的分岔频率相关性的验证

PWM型Buck-Boost功率变换器的频标可用于预测不同频率运行下的第一个分岔点.本论文首先推导出功率变换器新型频率的相关性.这是在高频工作下由仿真实验结果验证得到的.     

小型化直流电源发展动态

随着电子整机向小型化、轻量化方向的发展，对整机所用的直流稳压电源也提出了小型化的要求。本文叙述了国外ＤＣ／ＤＣ变换器的研究与开发情况，介绍了国内发展集成化直流稳压电源的现状，分析了国内市场对ＤＣ／ＤＣ变换器的需求。对国内外在该领域的技术水平进行了比较，提出了发展我国小型化直流电源的对策。     

Novel Current-Mode AC/AC Converters With High-Frequency AC Link

A novel circuit-topology family of the current-mode AC/AC converter with high-frequency AC link, based on a Flyback converter, is proposed. These circuit topologies, which can transfer one unregulated sinusoidal voltage with high total harmonic distortion (THD) into another regulated constant-frequency sinusoidal voltage with low THD, are composed of input cycloconverter, high-frequency storage transformer, and output cycloconverter. The circuit-topology family includes single four-quadrant power switch mode, push-pull mode, half-bridge mode, and full-bridge mode circuits. The single four-quadrant power switch mode and push-pull mode converters are suitable for low input voltage fields, but the half-bridge mode and full-bridge mode converters are suitable for high input voltage fields. The operational mode, steady principle, and transient voltage feedback control strategy of the kind of converter are investigated. The output characteristic curve, its relation to internal resistance, and the design criteria for the key circuit parameters are given. The theoretical analysis and the test result of the 500 VA 220 V 15% 50 HzAC/220 V 50 HzAC prototype have shown that the converters have advantages such as high-frequency galvanic isolation, simple topology, two-stage power conversion [low frequency alternating current (LFAC)/high frequency alternating current (HFAC)/LFAC], bidirectional power flow, high efficiency, high power density, low THD of the output voltage, strong adaptability to various loads, higher line power factor, low audio noise, etc.     

用于高效DC/DC变换器的沟槽MOSFET

面对市场对高效率电源的需求,工程师们无不急切期盼快速开关、低rDS(on)的功率MOSFET能有新进展。如今,一种新颖的厚底层氧化物工艺可以让Crss减小为栅极结构器件相应参数的一半,从而大大减少了器件导通所需的栅电荷,缩短了功率MOSFET的开关瞬态过程,同时让导通电阻保持在一个极低的水平上。这一技术对DC/DC变换器来说,意味着电路工作效率将得以提高。     

Digital Hysteretic Voltage-Mode Control for DC–DC Converters Based on Asynchronous Sampling

This paper investigates a digital voltage-mode controller for dc–dc converters based on hysteresis modulation. The control structure implements a high-bandwidth hysteretic differentiator as its main building block, and realizes a nonconventional structure of PID compensation with performances comparable to analog hysteretic controls, thus breaking the bandwidth and dynamic limitations commonly encountered in typical digital control arrangements. The employment of an asynchronous A/D converter based on the threshold inverter quantization concept dramatically shrinks the average delay time that separates the sampling instant from the corrective control action. Moreover, the hysteretic nature of the derivative action results in an inherent nonlinear response to large signal load variations, which translates into fast control intervention and reduced settling times. The hysteretic differentiator employs a ring-oscillator-based modulator, which ensures resolution up to 390 ps without asking for a high-frequency clock. Both the 6-bit asynchronous A/D converter and the ring-oscillator-based modulator are designed and manufactured in the same IC using a standard 0.35 $mu$m CMOS process. Analytical modeling, computer simulations, and experimental results on a synchronous buck converter confirm the validity of the approach and the dynamic performances achievable by the proposed control architecture.      

一种应用于DC/DC转换器的自举电路设计

设计了一种适用于DC/DC转换器的自举升压电路.采用该电路可将功率PMOS管替换为NMOS管.在相同尺寸条件下,NMOS管具有较小的导通电阻,从而提高DC/DC转换器的效率.电路基于华宏NEC的0.35 μm BCD工艺,利用Cadence中的Spectre进行了验证.并给出了该自举电路的设计思想、电路的工作原理,以及自举电容最小值的计算.当电源电压降至1.4 V,电路仍能保持正常工作.当自举电容为10 nF,电源电压为5 V,工作频率可高达2 MHz.     

Nonlinear Modeling of DC/DC Converters Using the Hammerstein's Approach

This paper deals with the modelling of highly nonlinear switching power-electronics converters using black-box identification methods. The duty cycle and the output voltage are chosen, respectively, as the input and the output of the model. A nonlinear Hammerstein-type mathematical model, consisting of a static nonlinearity and a linear time-invariant model, is considered in order to cope with the well-known limitations of the more common small-signal models, i.e. the entity of the variations of the variables around a well-defined steady-state operating point and the incorrect reproduction of the steady-state behavior corresponding to input step variations from the above steady-state operating point. The static nonlinearity of the Hammerstein model is identified from input-output couples measured at steady state for constant inputs. The linear model is identified from input-output data relative to a transient generated by a suitable pseudorandom binary sequence constructed with two input values used to identify the nonlinearity. The identification procedure is, first, illustrated with reference to a boost DC/DC converter using results of simulations carried out in the PSpice environment as true experimental results. Then, the procedure is experimentally applied on a prototype of the above converter. In order to show the utility of the Hammerstein models, a PI controller is tuned for a nominal model. Simulation and experimental results are displayed with the aim of showing the peculiarities of the approach that is followed.     

DC/DC转换器中电流采样电路的设计

设计了一种用于DC/DC开关电源转换器的新型电流采样电路.常见的电流采样电路是通过检测采样管串联电阻上压降来得到采样电流,而该采样电路是通过检测开关管串联电感上压降来得到采样电流的.由于后者所需电阻更少,从而降低了采样电路的功耗,提高了效率;并且由于电感上压降对采样电流变化的灵敏度更高,有效地提高了采样的精度.     

LHB1900系列混合集成DC／DC变换器的研制

ＬＨＢ１９００系列混合集成ＤＣ／ＤＣ变换器，采用厚膜混合集成电路技术制作，电路采用恒频４００ＫＨｚＰＷＭ推挽结构，功率密度５００ｍＷ／ｍ３，效率达８０％，本文简要介绍ＤＣ／ＤＣ变换器电路设计及工艺制作技术，该系列ＤＣ／ＤＣ变换器可用于军事、航空航天及其它可靠性要求高的领域。     

为最新电信应用而设计的DC／DC转换器

性能需求日益苛刻 迅速发展的电信应用为解决单个板级电信产品的供电问题,对高可靠性DC/DC转换器的需求不断增强。一方面,系统板的电路密度越来越高,使得一代又一代的电信设计不断要求在更小的空间内从DC/DC电源获配更多的电力。另一方面,为满足不断增长的对高带宽的需求,电信设计一直遵循微处     

DC/DC变换器输入阶跃响应测试方法研究

介绍了DC/DC变换器输入阶跃响应的概念和测试原理,对该参数的测试技术进行了探索,开发出适合的测试方法和测试系统。通过产品的测试,验证了测试方法和测试系统的准确性。该测试方法符合SJ20646-97《混合集成电路DC/DC变换器测试方法》的规定。该测试方法和系统适用于大动态输入范围和大功率DC/DC变换器输入阶跃响应的测试。     

DC／DC转换器的特点及质量保证体系

介绍国外主要航天用DC／DC转换顺生产厂家及其产品，并分析各个公司DC／DC转换器的质量保证体系。对选择合适的航天DC／DC转换器具有指导意义，同时为国内航天用DC／DC转换器的生产厂家提供一定的参考。     

DC/DC转换器的散热管理

模块化的DC/DC转换器功率密度不断增大,因此在设计或选择电源时,不能低估或忽略转换过程中产生的热量。具有鲁棒性的设计要求在任何操作条件下都不能超出温度限度并还需足够的余量。本文讨论了DC/DC转换器的三种散热方案,并给出了设计实例。     

连续导电模式下的单电感多输出DC／DC变换器

系统分析了单电感多输出DC／DC变换器结构,及其采用分时复用原理实现多路输出。由于电感共享,各输出支路间存在着严重的交叉影响。当输出支路严格工作在不连续导电模式（DCM）或伪连续导电模式（PCCM）下,可有效抑制交叉影响。文中采用一种新的控制方式,利用各支路输出电压的共模电压、差模电压分别控制输入半桥、输出半桥占空比,在连续导电模式（CCM）模式下实现了几乎没有交叉影响的多路输出。     

General Control Considerations for Input-Series Connected DC/DC Converters

This paper discusses the general control problems of dc/dc converters connected in series at the input. As the input voltage is shared by a number of dc/dc converters, the resulting converter relieves the voltage stresses of individual devices and hence is suitable for high input-voltage applications. At the output side, parallel connection provides current sharing and is suitable for high output-current applications. Moreover, series connection at the output side is also possible, resulting in output voltage sharing. Theoretically, from a power balance consideration, one can show that fulfillment of input-voltage sharing implies fulfillment of output-current or of output-voltage sharing, and vice versa. However, the presence of right-half-plane poles can cause instability when the sharing is implemented at the output side. As a consequence, control should be directed to input-voltage sharing in order to ensure a stable sharing of the input voltage and of the output current (parallel connection at output) or output voltage (series connection at output). In this paper, general problems in input-series connected converter systems are addressed. Minimal control structures are then derived and some practical design considerations are discussed in detail. Illustrative examples are given for addressing these general control considerations. Finally, experimental prototypes are built to validate these considerations.      

Small-Signal Dynamic Analysis of Regulated Class E DC/DC Converters

Class E dc/dc converters can operate at high switching frequencies with very low switching power losses. Using commercially available power transistors and diodes, Class E converters can operate at switching frequencies in the low-MHz range, with efficiencies of about 85 percent. Previous papers dealt with the circuit parameter values needed to obtain high-efficiency operation and output-voltage regulation, and with the static control characteristics of the Class E dc/dc converter cell. The analysis is extended to include the dynamic control characteristics and further information about the static characteristics. The theoretical predictions are verified by experimental measurements on a 40-W 1.5-MHz converter.     

采用磁集成技术的低压大电流DC/DC变换器的仿真

运用回转器一电容模型可以很好的理解磁性器件，特别是复杂的集成磁件。文章运用磁导电容类比建模法建立了磁件的回转器一电容模型。在回转器一电容模型中，磁路由容性电路来模拟，绕组由双端口的回转器来代替。进行了采用磁集成技术的低压大电流DC／DC变换器的仿真。仿真电路拓扑是原边不对称半桥、副边倍流整流电路。磁集成变压器的结构是Wei Chen提出的原边绕于中柱的只在侧柱开气隙的倍流整流磁集成结构。建立了用SPICE语言描述的回转器仿真模型。仿真软件是MULTISIM2001。     

PWM型DC/DC开关变换器的自抗扰控制策略

文章介绍了自抗扰控制器的原理和结构。结合开关变换器脉动和非线性的特点，介绍了自抗扰控制器在DC—DC开关变换器中的应用；并对具体的Buck电路进行了建模、仿真和实验，结果验证了控制策略的优良性。     

星载DC/DC转换器辐射损伤预警方案设计

星载DC/DC转换器是卫星、航天电子设备中辐射易损单元之一.文中采用国际上新兴的电子故障预测与健全管理方法(ePHM),设计了基于PWM的星栽DC/DC转换器辐射损伤预警方案,可以在辐射致PWM损伤使基准电压漂移达到预警值时发出警报,为启动备用件赢得超前时间,避免卫星出现灾难性故障.