基于PWM技术的新型高效率直流斩波器

本系统以Buck降压,Boost升压斩波电路为核心设计新型高效率直流斩波器。通过STM32检测显示输出电流,以及对电路的过充保护。采用TL494产生频率为150k Hz的PWM波形,进行闭环反馈控制,从而实现稳压输出电流可调。实验结果表明:充电模式时,电源输入的直流电压在比较宽的范围内变化时,电源输出直流电压能够保持较高的稳定性且变化率不大于1%。电流可进行线性步进,控制精度为0.05%,效率达到91%以上。放电模式时,输出电压恒定,变换器效率可达96%。本电路能够自动转换工作模式,且重量在500g以内。     

A new controller for boost dc–dc converters based on a novel sliding surface

ABSTRACT

In this paper, two control schemes for boost converters affected by uncertainties in input voltage and load are proposed. The boost converter dynamics is redefined in terms of new state variables to facilitate the use of a disturbance observer that can estimate matched and unmatched disturbances. A sliding surface, which is new in the context of boost converters, is proposed to enable tracking and regulation of output voltage without requiring measurement of input voltage and load current. The stability of the overall system including the disturbance observer, the sliding variable and the output is proved. The performance of the schemes is assessed for regulation of output voltage and tracking of reference voltage by simulation as well as experimentation in which various types of uncertainties and various types of reference voltages are considered.     

All-digital controlled boost DC–DC converter with all-digital DLL-based calibration

Traditional digital controls mostly use digital–analog converters to convert input and output voltages into digital coding to achieve control. This paper proposes the use of two digital ramps with two different frequencies to replace a digital–analog converter. This approach can produce seven bit resolution for the DPMW signal. In addition, we use an all-digital DLL phase correction concept to further enhance the resolution of the DPWM signal by an additional three bits, resulting in 10-bit DPWM signal resolution. The proposed circuit uses 0.35 μm CMOS processes, with a core area of 0.987 mm², a system switching frequency of 500 KHz, an input voltage range of 3.3–4.2 V, and an output voltage range of 5 V. Output voltage measurement accuracy reaches 99%, while the system reaches efficiency of 91% with output loads of up to 500 mA.     

单周期控制无桥Boost PFC电路分析和仿真

传统有源功率因数校正电路中导通器件多，通态损耗大，不适于中大功率场合应用。新颖的单相功率因数校正电路——无桥Boost拓扑，其结构简单，效率高。文中基于无桥Boost电路，提出一种单周期控制方法，它不需要检测输入电压信号且不需使用乘法器就能实现功率因数校正。单周期控制电路简单可靠，又降低了成本。文中分析了无桥Boost电路及单周期控制的工作原理，并导出了控制系统的稳定性条件。     

抗总剂量Boost型 DC-DC转换器设计

采用设计加固方法,基于标准商业0.35微米CMOS工艺,设计了抗总剂量Boost型 DC-DC转换器芯片。从系统设计角度出发,综合采用了同步整流、高开关频率、自适应动态斜坡补偿等技术提高DC-DC转换器性能和抗辐照能力;分别从电路级和器件级对转换器进行了加固设计。考虑DC-DC转换器总剂量效应,电路级加固分别从模拟电路加固和数字电路加固着手;提高环路稳定裕度,有效的提高转换器反馈环路的抗总剂量能力。为有效的降低场区辐射寄生漏电,器件级采取的加固措施是转换器的控制部分MOS管采用H栅实现,输出功率MOS管采用环形栅实现。辐照实验结果表明,设计的抗总剂量Boost型 DC-DC转换器在总剂量超过120 krad (Si )后才出现功能失效,而非加固的电路在总剂量超过80 krad (Si )后才出现功能失效;加固电路的辐照后电流明显小于非加固电路;加固电路的辐照后效率也高于非加固电路。     

一种临界导电模式的功率因数校正电路

使用有源功率因数校正技术可有效抑制电网电流谐波和提高开关电源功率因数。文中分析了临界导电模式Boost型功率因数校正电路的电路结构及其工作原理,应用反馈控制理论,研究了功率因数校正环节的控制特性,给出了其电路参数的设计方法,保证在电网电压和负载功率大范围变化时,功率因数维持在0.99 以上。     

Solar Energy System with Digital Controller for Grid Connected Systems

The solar photovoltaic (PV) module output voltage changes according to the variation of light intensity and temperature. This paper presents the implementation of an automatic digital controller of a DC-DC boost converter without batteries for a solar cell module by using a peripheral interface controller, which forms a closed loop, to control the ON-OFF period of the switching pulse. The output of DC-DC converter is maintained by automatically increasing or decreasing the pulse width. To produce the pulse width modulation (PWM), the microcontroller is programmed according to the required duty cycle for the power switch. The PWM ON period is increased with the decrease in the PV voltage and vice-versa. The input voltage to the inverter is maintained constantly and is converted into an AC signal by using the metal-oxide-semiconductor field effect transistor (MOSFET) H-bridge operated in the sinusoidal pulse width modulation mode by using a PIC (peripheral interface controller) microcontroller. The generated AC signal can be connected to the AC grid or to the AC load. The simulated results by using Proteus 8 and hardware implemented results verify the effectiveness of the proposed controller.     

一种基于TL494Boost型DC-DC电源设计

利用单片机MSP430F449,以电压型PWM控制器TIA94为核心,设计了一种Boost型稳压输出开关电源。该系统电路结构简单,直流输出电压可调范围为30-36V,效率高达90％,具有过流、过压保护并可实时显示输出电压与电流值。文中给出了详细设计思路和器件参数计算过程,并进行了实验验证。     

普及型手机LCD背光趋向使用LDO

文章从技术和市场经济的角度对手机LCD背光LED驱动器的技术演变进行分析,论述了LDO的性价比为普及型手机LCD背光应用赢得新的机遇。     

一种交错并联型Boost PFC的建模与设计

交错并联型Boost PFC相对于单级Boost PFC具有硬件设计相对简单,输出纹波小,功率密度高等优点。本文针对交错型Boost PFC进行了原理分析,包括其工作过程,通过状态空间平均法建立的数学模型,以及电流纹波的分析。最后制作了一台4KW的样机实物,并测试了相关参数。