峰值电流模式控制的非理想Buck变换器的建模

在 Ridley 峰值电流模式控制的 Buck 变换器模型的基础上,提出一个包含传导损耗的修正模型.运用平均开关建模法,建立非理想PWM开关的非线性大信号平均模型.包含全部寄生电阻和二极管的正向压降.围绕某一稳态工作点,扰动并线性化平均模型,导出非理想Buck变换器的功率级在连续工作模式下的直流模型和线性小信号模型.在此基础上.修正峰值电流模式控制部分的小信号模型参数.最终建立整个峰值电流模式控制的非理想Buck变换器的线性小信号模型.推导小信号动态的解析结果.给出修正的补偿斜坡信号斜率.在Simetrix/simplis开关电源软件包中进行了仿真分析,结果显示新模型能更准确地预测系统性能.     

A Chaotic Peak Current-Mode Boost Converter for EMI Reduction and Ripple Suppression

A novel chaotic peak current-mode boost converter is proposed. By deriving its corresponding current mapping function, a thorough analysis of its chaotic behavior is carried out. As demonstrated both in simulations and experiments, the proposed design can effectively reduce electromagnetic interference and suppress ripples of the converter's output, resulting in a better design for power supplies.      

电流型控制移相全桥变换器建模及最优化

建立了电流型控制移相全桥变换器主电路的小信号模型,并根据其给出闭环传递函数。以AISE最小为优化目标采用连续优化算法ALAPT和离散优化算法MDOD相结合进行求解。     

Inductor Current Sampled Feedback Control of Chaos in Current-Mode Boost Converter

A chaos control strategy for chaotic current-mode boost converter is presented by using inductor current sampled feedback control technique.The quantitative analysis of control mechanism is performed by establishing a discrete alterative map of the controlled system.The stability criterion,feedback gain,and corresponding critical duty ratio are obtained from the eigenvalue of the map.The simulation results verify the t heoretical analysis results of the control strategy.     

Digital Peak Current Control for Switching DC–DC Converters With Asymmetrical Dual-Edge Modulation

An asymmetrical dual-edge modulation (ADM) method applied to digital peak current (DPC)-controlled switching dc–dc converters is proposed in this brief. Steady-state and transient performance comparison of DPC-controlled buck converters with ADM and conventional symmetrical dual-edge modulation (SDM) is presented and verified by experimental results. Comparison studies show that the steady-state and transient performances of DPC with ADM are better than those of DPC with SDM.      

Dynamics and Operation-State Estimation of Current-Mode Controlled Flyback Converter

By utilizing total magnetic flux φ of the primary and secondary windings of the flyback transformer as a state variable,the discrete-time model of current-mode controlled flyback converter is established,upon which the bifurcation behaviors of the converter are analyzed and two boundary classification equations of the orbit state shifting are obtained.The operation-state regions of the current-mode controlled flyback converter are well classified by two boundary classification equations.The theoretical analysis results are verified by power electronics simulator(PSIM).The estimation of operation-state regions for the flyback converter is useful for the design of circuit parameters,stability control of chaos,and chaos-based applications.     

Model Predictive Control of an Asymmetric Flying Capacitor Converter

Multilevel converters and, in particular, flying capacitor (FC) converters are an attractive alternative for medium-voltage applications. FC converters do not need complex transformers to obtain the dc-link voltage and also present good robustness properties, when operating under internal fault conditions. Unfortunately, with standard modulation strategies, to increase the number of output voltage levels of FC converters, it is necessary to increase the number of cells and, hence, the number of capacitors and switches. In this paper, we develop a finite-state model predictive control strategy for FC converters. Our method controls output currents and voltages and also the FC voltage ratios. This allows one to increase the number of output voltage levels, even at high power factor load conditions and without having to increase the number of capacitors and switches. Experimental results illustrate that the proposed algorithm is capable of achieving good performance, despite possible parameter mismatch.      

Widely Tunable Separate Absorption and Modulation Wavelength Converter With Integrated Microwave Termination

A widely tunable wavelength converter utilizing a separate absorption and modulation configuration and only dc bias connections is demonstrated. The device integrates an SG-DBR laser with a traveling-wave electroabsorption modulator and an optically pre-amplified receiver and introduces a simplified bias scheme by the inclusion of passive resistor and capacitor circuit elements. We discuss a the design of these passive elements and their compatibility with fabrication of photonic integrated circuits. The device demonstrates over 12 GHz optical bandwidth and error free 10 Gb/s wavelength conversion is achieved with less than 2.5 dB power penalty over 25 nm of output tuning.     

基于预测电流控制的三电平并网变流器研究

概述并网用网侧变流器工作原理,分析其工作模式,探讨了基于只与开关频率相关的预测电流控制（PCFF）和电网电压前馈相结合的控制策略,该策略能够弥补三电平变流器直流侧电容电压不平衡的先天性缺陷,而且PCFF控制下的系统有快速的动态响应,特别易于数字化实现。构建仿真模型分析验证了控制策略的有效性和可行性。     

Energy-Efficient Peak-Current State-Machine Control With a Peak Power Mode

The peak-current control that is modeled in this paper is a novel variable-frequency control that maintains regulation in a flyback converter by enabling and disabling cycles instead of modulating the pulse width, which allows for elimination of feedback compensation and can provide for peak power three times higher than the rated full-load power without increasing the power supply component sizes. A state machine sets the peak current of each enabled cycle, based on the load requirements. The variable-frequency nature of this control scheme reduces switching losses significantly at light loads, while the lowering of the peak current by the state machine reduces the output ripple and audible excitations of the transformer. The state-machine control is completely modeled for the first time, including new modeling for the maximum power deliverable in continuous conduction mode (CCM), the peak-current ratio between states, the number of states required for stability, the minimum number of counts for state transitions required for stability, and modeling for a new peak state with double the maximum switching frequency, which provides peak power during brief peak loads, without requiring an overrated transformer . Characterization of a supply that was designed around the monolithic IC that uses this control scheme is provided.      

Fast-Transient PCCM Switching Converter With Freewheel Switching Control

This brief presents a new switching converter operating in pseudo-continuous-conduction mode (PCCM) with freewheel switching control. Compared with conventional discontinuous-conduction mode (DCM) converters, this converter demonstrates much improved current handling capability with reduced current and voltage ripples. The control-to-output transfer function exhibits a single-pole behavior, making the load transient response much faster than its CCM counterparts. Simulation and experimental results show that, with a 6-V, 6-W load and a 10-V unregulated supply, the PCCM converter has a current ripple of only 1.1 A and a ripple voltage of only 58 mV, while a DCM converter has a current ripple of 2.2 A and a ripple voltage of 220 mV. In addition, the PCCM converter takes only 25 mus to respond to a 500-mA load current change while a CCM one requires 1.4 ms.     

Modeling and Control of PV Charger System With SEPIC Converter

The photovoltaic (PV) stand-alone system requires a battery charger for energy storage. This paper presents the modeling and controller design of the PV charger system implemented with the single-ended primary inductance converter (SEPIC). The designed SEPIC employs the peak-current-mode control with the current command generated from the input PV voltage regulating loop, where the voltage command is determined by both the PV module maximum power point tracking (MPPT) control loop and the battery charging loop. The control objective is to balance the power flow from the PV module to the battery and the load such that the PV power is utilized effectively and the battery is charged with three charging stages. This paper gives a detailed modeling of the SEPIC with the PV module input and peak-current-mode control first. Accordingly, the PV voltage controller, as well as the adaptive MPPT controller, is designed. An 80-W prototype system is built. The effectiveness of the proposed methods is proved with some simulation and experimental results.     

A Current-Mode DC-DC Buck Converter with High Stability and Fast Dynamic Response

提出了一种高稳定性的电流型DC-DC转换器.首先应用一种新型的电流型转换器的模型推导了控制环路的增益表达式,在分析其环路增益的基础上,提出了一种新颖的控制环路频率补偿的方法,从而使转换器的稳定性不受负载电流和电源电压变化的影响.其次应用这种新的频率补偿方法,使用0.5μm-CMOS工艺设计了一种电流模式的降压型转换器.仿真结果表明,该稳压器具有高度的稳定特性,其稳定性与负载和电源电压无关.并且由于这种新的频率补偿为环路提供了极高的带宽,所以该转换器具有优异的动态响应.其提供的全负载瞬态响应的建立时间小于5μs,过冲电压小于30mV.     

Predictive Current Control Strategy With Imposed Load Current Spectrum

This paper presents a modified predictive current control strategy which allows one to have control over the spectrum of the load current. The proposed method uses a model of the system to predict the behavior of the current for each possible voltage vector generated by the inverter. For that purpose, at each sampling interval, signal predictions are evaluated using a cost function that quantifies the desired system behavior. The cost function used in this work evaluates the filtered error of the load currents. The inclusion of a filter for the load error allows one to manipulate current spectra. Thus, by designing this filter appropriately, the load spectrum can be shaped. The performance of the proposed control strategy is verified by simulation and experimental results.     

基于预测控制的三相双降压逆变器统一调制策略

针对三相双降压逆变器(Dual Buck Inverter,DBI)这种无需死区时间、开关频率较高、输出高功率因数的变换器调制策略较多的问题,将现有的3种不同的调制策略进行结合,引入预测控制方法,提出统一的调制策略。所提方法能够在同一种控制方法下切换正弦脉宽调制策略(SPWM),空间矢量脉宽调制策略(SVPWM)和不连续空间矢量脉宽调制策略(DSVPWM)3种不同的调制方法,实现控制方法的简化。通过仿真与实验验证了3种调制方法之间的切换,同时对比了3种不同调制方法下的逆变器传输效率。     

Optimal Predictive Control of Three-Phase NPC Multilevel Converter for Power Quality Applications

This paper presents the optimal control of the ac currents, the dc voltage regulation, and the dc capacitor voltage balancing in a three-level three-phase neutral point clamped multilevel converter for use in power quality applications as an active power filter. The ac output currents and the dc capacitor voltages are sampled and predicted for the next sampling time using linearized models and considering all the 27 output voltage vectors. A suitable quadratic weighed cost function is used to choose the voltage vector that minimizes the ac current tracking errors, the dc voltage steady-state error, and the input dc capacitor voltage unbalancing. The obtained experimental results show that the output ac currents track their references showing small ripple, a total harmonic distortion (THD) of less than 1%, harmonic contents that are 46 dB below the fundamental, and almost no steady-state error (0.3%). The capacitor voltages are balanced within 0.05%, and the balancing is assured even when redundant vectors are not chosen. Near-perfect capacitor dc voltage balancing is obtained while reducing current harmonic distortion. Some experimental evidence of robustness concerning a parameter variation was also found, with the optimum controller withstanding parameter deviations from $+$100% to $-$50%. Compared to a robust sliding mode controller, the optimal controller can reduce the THD of the ac currents or reduce the switching frequency at the same THD, being a suitable controller for power quality in medium-voltage applications.      

Joint Adaptive Modulation and Diversity Combining With Downlink Power Control

We consider the problem of finding low-complexity, bandwidth-efficient, and processing-power-efficient transmission schemes for a downlink scenario under the framework of diversity combining. Capitalizing on recent results for joint adaptive modulation and diversity combining (AMDC) schemes, we design and analyze two AMDC schemes that utilize power control to reduce the radiated power and, thus, the potential interference to other systems/users. Based on knowledge of channel fading, the proposed schemes adaptively select the signal constellation, diversity combiner structure, and transmit power level. We show that the novel schemes also provide significant average transmit power gains compared to existing joint adaptive quadratic-amplitude modulation (QAM) and diversity schemes. In particular, over a large signal-to-noise ratio (SNR) range, the transmitted power is reduced by 30%-50%, yielding a substantial decrease in interference to coexisting systems/users, while maintaining high average spectral efficiency, low combining complexity, and compliance with bit-error-rate constraints.     

Digital Multimode Buck Converter Control With Loss-Minimizing Synchronous Rectifier Adaptation

This paper develops a multimode control strategy which allows for efficient operation of the buck converter over a wide load range. A method for control of synchronous rectifiers as a direct function of the load current is introduced . The function relating the synchronous-rectifier timing to the load current is optimized on-line with a gradient power-loss-minimizing algorithm. Only low-bandwidth measurements of the load current and a power-loss-related quantity are required, making the technique suitable for digital controller implementations. Compared to alternative loss-minimizing approaches, this method has superior adjustment speed and robustness to disturbances, and can simultaneously optimize multiple parameters. The proposed synchronous-rectifier control also accomplishes an automatic, optimal transition to discontinuous-conduction mode at light load. Further, by imposing a minimum duty-ratio, the converter automatically enters pulse-skipping mode at very light load. Thus, the same controller structure can be used in both fixed-frequency pulsewidth modulation and variable-frequency pulse-skipping modes. These techniques are demonstrated on a digitally-controlled 100-W buck converter     

峰值电流型PFC Boost变换器斜坡补偿的时变模型和全局动态优化试验

建立连续峰值电流型PFC Boost变换器的时变模型,动态分析快时标不稳定现象的产生,并结合电路试验,分析常规固定斜坡补偿的不足.以斜坡补偿时变模型为基础,以工频输入电流正弦化为目标,提出一种全局优化的动态时变补偿设计理论和方法.基本原理电路试验结果表明全局优化动态补偿既消除了快时标不稳定现象,又获得了单位功率因数,达到了全局补偿优化的目的.     

Separate Absorption and Modulation Mach-Zehnder Wavelength Converter

A monolithic separate absorption and moduation region (SAM) wavelength converter is demonstrated. The transmitter consists of a sampled-grating DBR (SGDBR) laser and a series-push-pull Mach-Zehnder modulator. The preamplified receiver is composed of a flared semiconductor optical amplifier and a quantum-well pin photodetector. Integrated resistors and capacitors are used to minimize microwave losses and remove the need for external bias tees. The design, fabrication, and operation of this photonic integrated circuit is presented. Small-signal response measurements show a device bandwidth in excess of 20 GHz. Operation at 40 Gbps with NRZ data shows less than a 2.5-dB power penalty across the 32-nm laser tuning range with no additional power penalty for conversion to the input wavelength.