峰值电流控制DC-DC Boost变换器优化斜坡补偿

非线性现象在DC-DC开关变换器中普遍存在,具体表现为次谐波振荡和混沌等不稳定现象。针对此,研究了峰值电流控制下的DC-DC Boost变换器,通过采取固定斜坡补偿可消除其电路中的非线性现象,但降低了参考电流和输入功率。为解决上述问题,提出了一种优化的斜坡补偿方案来解决固定斜坡补偿带来的参考电流和输入功率降低的问题,同时推导出其参考电流和电感电流平均值的表达式,通过仿真和实验验证了理论分析的正确性及所提优化补偿策略的有效性。     

谷值V2控制Boost变换器原理及稳定性分析

分析了Boost变换器的输出电压纹波,将谷值V2控制技术应用于Boost变换器。详细分析了谷值V2控制Boost变换器的工作原理,讨论了系统的稳定性,研究了斜坡补偿对其稳定性的影响。搭建了基于PSIM软件的仿真模型和实验平台,仿真及实验结果表明:工作于连续导电模式的谷值V2控制Boost变换器稳定工作范围为占空比大于0.5;在占空比小于0.5时会发生次谐波振荡,该次谐波振荡可以通过加入适当的斜坡补偿有效地消除。     

光伏发电系统中双环电流模式Boost变换器的研究

在光伏发电系统中,前级Boost升压变换器采用单环电压模式控制时,动态响应速度慢,系统的稳定性差,针对上述问题,利用UC3842设计了双环电流模式控制系统、内部电流环和外部电压环。先对内部电流环进行斜坡补偿,然后推导控制系统的开环传递函数,根据其开环频率特性对外部电压环进行PI调节,提高系统的动态响应速度和稳定性。试验结果与理论分析一致,证明了双环电流模式控制系统具有动态响应速度快和稳定性好等优点,控制效果较好。     

峰值电流控制二次型Boost变换器

二次型Boost变换器因其具有宽输入电压范围特性而得到广泛关注.与传统Boost变换器相比,二次型Boost变换器含有两个LC滤波器,呈现四阶动力学特性.本文提出将二次型Boost变换器输入电感电流和输出电容电压作为反馈信号的峰值电流控制策略,简化了控制环路设计.实验结果验证了峰值电流控制二次型Boost变换器具有瞬态...     

开关电感并联Boost变换器的动力学行为及混沌控制

开关电感并联Boost变换器的非线性行为严重影响系统的性能。为研究变换器参数变化对系统性能的影响,建立系统的离散映射模型。通过分岔图观察变换器参数变化时其非线性动力学的演化过程,研究发现考电流、负载电阻增大时,变换器并不遵循周期倍增的分岔轨迹,而是在2倍周期后突然激变为6倍、8倍周期运行并通往混沌;当输入电压、电感数值减少时,变换器极易发生突变而进入混沌态;而当开关频率增大时,输出纹波减少,但不能让变换器稳定运行在单周期态。针对这些非线性动力学行为,提出一种指数延迟反馈控制方法对系统施加控制。搭建的仿真模型证明这种特殊的非线性现象的存在,验证所提出的控制方法控制方法的有效性。     

高频Boost变换器稳定运行的参数域分析

高频条件下的Boost变换器具有功率密度大、转换效率高和适于大规模集成等特点而备受关注,但因其强非线性特性,在工作中更容易因参数选择不当或外部受到大干扰使得系统产生分岔和混沌现象。通过建立高频Boost变换器的频闪映射模型,利用Jacobian矩阵特征值变化判断系统的稳定参数域,分析了该变换器各参数在不同条件下产生分岔的情况,通过电路仿真及实验验证了高频Boost变换器中出现的分岔及混沌现象与理论分析结果一致。本结论能够为Boost变换器在高频条件下维持稳定运行提供参考,也为系统的进一步优化设计和控制提供理论依据。     

电流控制模式下Boost变换器的混沌行为

该文建立了Boost变换器在电流可编程控制模式下的离散数学模型和迭代方程,并通过仿真分析了不同分岔参数变化下的工作规律,证实了该变换器中的倍周期和混沌行为。     

基于时延反馈的Boost变换器混沌化控制

时延反馈是一种混沌或混沌化控制的有效方法,本文建立了电流模式控制DC-DC Boost变换器输出电压时延反馈混沌化模型,以非线性微分方程时延反馈混沌化理论为基础,研究了控制策略中不同控制参数对变换器混沌化的影响,并给出了控制参数的选择依据.时延反馈混沌化方法控制范围宽,结构简单且设计过程系统性强.同时,验证了变换器系统的混沌化对EMI的有效抑制,为相关混沌研究的工程应用提供了实现思路.     

峰值电流控制变换器斜坡补偿电路的优化设计

指出工作于DCM的变换器是稳定的,而工作于CCM且占空比D>0.5的峰值电流控制变换器需要进行斜坡补偿。论述了由单只电阻与电容简单串联构成的最佳斜坡补偿电路,分析了斜坡补偿系数与D的关系及斜坡补偿电路对振荡器参数的影响,论述了电流前沿尖峰滤波参数设计和斜坡补偿网络各元件参数的优化设计方法。文中给出了以UC3843控制的反激变换器设计实例,实验结果验证了理论分析的正确性和方案的可行性。     

多级脉冲序列控制Boost变换器

针对开关DC-DC变换器的非线性控制问题,提出多级脉冲序列控制方法,并对工作于电感电流断续模式的多级脉冲序列控制Boost变换器进行分析。多级脉冲序列控制策略通过在若干连续开关周期内,产生能量等级不同的控制脉冲信号所组成的脉冲序列,实现对DC-DC变换器功率电路的控制。分析了多级脉冲序列控制的基本原理和工作过程,并对多级脉冲序列控制断续工作模式Boost变换器进行了稳态工作特性分析和稳定性分析。与已有的脉冲序列控制相比,采用多级脉冲序列控制的Boost变换器在具有快速动态响应能力的同时,能够有效减小稳态工作时的输出电压纹波。仿真和实验结果验证了控制策略的可行性以及理论分析的正确性。     

峰值电流模式控制Boost PFC变换器斜波补偿设计

峰值电流模式控制Boost PFC变换器中存在着丰富的菲线性行为,为了控制以削弱不稳定现象的范围,工程上通常采用斜波补偿的方法,但完全靠设计经验.以非线性系统理论的分叉控制观点给出了系统稳定性的临界参数条件及判据,推导了斜波补偿法的参数选择公式,为设计电路时的参数选择提供了理论依据,对实际产品开发具有一定的指导意义.     

Boost矩阵变换器的离散滑模控制策略

针对目前矩阵变换器存在电压传输比低的缺陷,在对拓扑结构的基本构成及其工作原理分析基础上,提出一种新型的称为Boost矩阵变换器的电路拓扑结构.推导了其电压传输比与占空比之间函数关系的解析表达式,阐述了所采用的离散滑模控制策略的设计方法,并通过仿真对其有效性和可行性进行了验证.结果表明,该拓扑结构能实现输出电压和频率在一定范围内的任意调节,其电压传输比既可大于1,也可小于1,且直接输出高品质的正弦波而无需滤波环节,从而有效解决了传统矩阵变换器电压传输比低的难题.     

电容补偿与通用变频器节能原理及合理选用

从提高功率因数谈起,阐述交流电动机电容补偿与变频调速的节能原理,并对它们作以简单比较,以便合理选用配置,取得良好的经济效益.     

Analysis of high-power factor AC-DC boost converter

This paper presents analysis of a high-power factor ac-dc converter with a boost converter operating in the discontinuous conduction mode (DCM) and the critical conduction mode (CRM). The converter can be expressed by a nonlinear differential equation for each mode. The equation in DCM is solved analytically by separating its variable (output voltage) into two terms of a ripple component and a direct component, and by linearizing the equation for the ripple component. On the other hand, the equation in CRM can be solved analytically. Furthermore, the source current waveform of the converter is expanded into the Fourier series. As a result, the output voltage, its ripple and the power factor of the converter in DCM and CRM are derived as a function of the circuit parameters, respectively, and verified experimentally. These equations exhibit clearly the effect of each circuit parameter of the converter and the difference between the converter in DCM and in CRM. The converter operating in CRM produces sinusoidal ac current with unity power factor.     

Load voltage compensation using series–shunt power converter

This paper presents a method of amplitude control and unbalance compensation of the load voltage using a series–shunt power converter. The series power converter works to obtain a constant balanced sinusoidal load voltage. The shunt converter regulates the DC link voltage and compensates for the reactive current of the source within the rated current of the converter. To design the required capacity for the series–shunt power converter, the relation between the converter capacity and the load power factor at constant compensation voltage is introduced. The required capacity of the series–shunt power converter is reduced by more than 50% compared with that of a conventional series power converter. The effectiveness of the proposed load voltage compensation technique using the series–shunt power converter is verified by experiments. © 2001 Scripta Technica, Electr Eng Jpn, 136(3): 39–48, 2001     

Comparative evaluation of sliding mode fuzzy controller and PID controller for a boost converter

Nonlinear controllers such as fuzzy controllers and sliding mode controllers have been applied to boost converters because of their nonlinear properties. Although both fuzzy and sliding mode controllers have desirable characteristics, they have disadvantages in practice when applied individually. A sliding mode fuzzy controller is proposed to control boost converters. The sliding mode fuzzy controller combines the advantages of both fuzzy controllers and sliding mode controllers. It also has advantages of its own that are well suited for digital control design and implementation. A sliding mode fuzzy controller is designed and verified with experimental results using a prototype boost converter with a DSP-based digital controller. Experimental results of the boost converter using sliding mode fuzzy control are evaluated in comparison with experimental results using a linear PID and PI controller. The comparison indicates that the sliding mode fuzzy controller is able to obtain the desired transient response under varying operating points without chattering. The startup response using sliding mode fuzzy control is superior to the response using PID and PI control, while the load transient response shows no obvious advantage.     

基于纹波补偿的恒定导通时间控制Buck变换器

针对恒定导通时间(COT)控制的Buck变换器,在输出滤波电容的等效串联电阻(ESR)较小时出现次谐波震荡问题,提出了一种基于纹波补偿的恒定导通时间控制技术。通过引入输出滤波电容的等效串联电阻(ESR)的纹波电压补偿,使反馈电压的纹波得以增强,从而改善系统的稳定性。仿真和实验结果表明,采用提出的方法,当输出滤波电容的等效串联电阻(ESR)较小时,系统仍然具有较强的稳定性。     

COMBIVERT型变频器滑差补偿特性参数整定

介绍了ＣＯＭＢＩＶＥＲＴ型变频器滑差补偿特性的工作原理和功能,总结了滑差补偿特性参数的设置、调试的方法和步骤。     

Simulation of variable‐speed wind generation system using boost converter of permanent magnet synchronous generator

This paper proposes a variable‐speed wind generation system using the boost converter. The proposed system has three speed control modes for the wind velocity. The control mode of low wind velocity regulates the armature current of the generator with the boost converter to control the speed of wind turbine. The control mode of middle wind velocity regulates the DC link voltage with the vector controlled inverter to control the speed of wind turbine. The control mode of high wind velocity regulates the pitch angle of the wind turbine with the pitch angle control system to control the speed of the wind turbine. The hybrid combination of three control modes extends the variable‐speed range. The proposed system simplifies maintenance, improves reliability, and reduces the costs compared with the variable‐speed wind generation system using a PWM converter. This paper describes the control strategy and modeling for a simulation of the proposed system using Simulink of Matlab. It also describes the control strategy and modeling of a variable‐speed wind generation system using a PWM converter. The steady state and transient responses for wind velocity changes are simulated using Matlab Simulink. This paper verifies the fundamental performance of the system using a boost converter by discussing the simulation results of both systems. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(4): 37–54, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20902     

浅谈台线考核与降线损技术

城区配电线路线损偏高,10 kV及其以下配电网络的线损电量约占整个电力网的线损电量78％,因此合理设计馈线、采用无功补偿优化配置等节能降损技术措施,加强台线考核的十分必要.由于台线考核量大、面广而且所有数据需要在很短时间汇集到同一个平台,所以台线考核目标的实现更需要依靠一系列科学高效的技术措施和实施方案.