Predictive direct power control of three-phase PWM rectifier based on TOGI grid voltage sensor free algorithm

In predictive direct power control(PDPC)system of three-phase pulse width modulation(PWM)rectifier,grid voltage sensor makes the whole system more complex and costly.Therefore,third-order generalized integrator(TOGI)is used to generate orthogonal signals with the same frequency to estimate the grid voltage.In addition,in view of the deviation between actual and reference power in the three-phase PWM rectifier traditional PDPC strategy,a power correction link is designed to correct the power reference value.The grid voltage sensor free algorithm based on TOGI and the corrected PDPC strategy are applied to three-phase PWM rectifier and simulated on the simulation platform.Simulation results show that the proposed method can effectively eliminate the power tracking deviation and the grid voltage.The effectiveness of the proposed method is verified by comparing the simulation results.

The Research of Three-phase Boost/Buck-boost DC-AC Inverter

This paper presents a new inverter based on three-phase Boost/Buck-boost single-stage inverter. The basic configuration of the new topology and their fundamental principle are firstly introduced, the method of design double-loop controller and sliding mode controller are clarified, analyzed and compared in the following. Finally the validity and feasibility of the new topology are tested by simulation. The results indicate that regulation of the voltage transfer ratio and output frequency can be realized optionally by the new converter, furthermore the harmonic distortion of waveform is low. So the inherent drawback of low voltage transfer ratio of traditional converter is effectively settled. This study may provide inspiration for further engineering application.

Simulation of a kind of active harmonic reduction 18-pulse rectifier

To solve the input current harmonic pollution of the high power rectifier system,18-pulse rectifier based on a kind of active harmonic suppression technique at dc side is proposed in this paper.The pulse rectifier employs three-phase diode bridges,each of them followed by a boost converter.Unlike the conventional three-phase unity-power-factor diode rectifier,the ideal sinusoidal main currents of circuit topology are obtained by control its output current or input currents of three boost converters for approximately triangular modulation.The theoretical of modulation strategy and characteristics of input and output currents about the proposed rectifier are analyzed in detail.Simulation results by Matlab/Simulink demonstrate that the proposed rectifier draws nearly sinusoidal current and power quality index is improved.The correctness of the theoretical analysis is validated.

Power Factor Correction Rectifier with a Variable Frequency Voltage Source in Vehicular Application

This paper presents a PFCVF (Power Factor Correction) rectifier that uses a variable frequency source for alternators for electric and hybrid vehicles application. In such application, the frequency of the signal in the alternator changes according to the vehicle speed, more over the loading effect on the alternator introduces harmonic currents and increases the alternator apparent power requirements. To overcome these problems and aiming more stability and better design of the alternator, a new third harmonic injection technique is proposed. This technique allows to preserve a good THD (Total Harmonic Distortion) of the input source at any frequency and to decrease losses in semiconductors switches, thereby allowing more stability and reducing the apparent power requirements. A comparative study between the standard and the new technique is made and highlights the effectiveness of the new design. A detailed analysis of the proposed topology is presented and simulations as well as experimental results are shown.

基于半有源倍压整流的交错并联高增益Boost变换器

提出一种电流型Boost半有源倍压整流变换器,二次侧整流桥只有一个二极管承受输出电压,其余半导体器件和变压器二次绕组电压应力为输出电压的1/2。通过降低变压器匝比和减小其寄生参数,以及使用具有较小关断损耗和低导通电阻的低压器件,提高变换器在高频轻载时的效率。在一次侧占空比控制和二次侧移相控制基础上,分析其功率特性、软开关约束条件以及交错电流纹波特性,对比其与传统半有源变换器的性能,并搭建50 kHz/1 kW实验样机,来验证理论分析。

耦合电感型高增益Boost变换器拓扑分析

耦合电感型高增益Boost变换器在光伏、燃料电池等新能源并网系统中得到广泛重视,但鲜有文献阐述其拓扑构建思路及方法。为此,以基本耦合电感型Boost变换器为出发点,分析了其优点和不足;然后围绕如何抑制开关管电压尖峰、如何降低输出二极管电压应力、如何进一步提高电压增益,系统分析并推导了有源钳位、带整流单元、多绕组以及带倍压单元等四类改进的耦合电感型Boost变换器,明确了它们之间的内在联系及各自的性能特点;最后根据分析结果,选择一种带倍压单元的层叠型高增益Boost变换器进行实验研究,搭建了250W的实验样机,实测最大效率为97%。

Boost电路的一种软开关实现方法

提出了一种 Boost 电路软开关实现方法,即同步整流加上电感电流反向。根据两个开关管实现软开关的条件不同,提出了强管和弱管的概念,给出了满足软开关条件的设计方法。一个24V输入,40 V/2.5 A 输出,开关频率为200 kHz 的同步 Boost 变换器样机进一步验证了上述方法的正确性,其满载效率达到了96.9%。

单相半桥式BOOST整流电路的仿真研究

分析了单相半桥式boost整流电路的拓扑结构和操作模式,并探讨了该电路关键参数的选取依据. 在Matlab/Simulink仿真平台上,应用电流滞回控制方法实现了电路的有源功率因数校正.

一种新的三相Boost-PWM整流器控制技术

针对传统的三相Boost-PWM整流器控制技术在电网电压不平衡和变换器输入阻抗不相等时控制性能不理想,本文提出一种新的控制方法。首先分析和建立了三相Boost-PWM整流器的数学模型,该模型放宽了原控制方法中要求电网电压平衡和输入阻抗相等的条件,在保持输出功率不变的基础上,求出三相电流的期望值。在电流环控制上,采取正负序分量分解和静止的三相到两相坐标变换,在两相坐标系中,实现对正序分量幅值和负序分量幅值的分别控制。仿真和实验结果表明,该方法在电压平衡或不平衡下均能得到低次谐波的输入电流和单位功率因数,在输入阻抗不平衡度达到三倍时,仍能得到较高的功率因数。

基于0.5m CMOS工艺的BOOST变换器设计

针对便携式通信设备对DC-DC变换器的输出电压纹波和效率要求较高的问题,提出了一种同步整流模式的BOOST型DC-DC变换器电路,以提高芯片的转换效率。该设计采用CSMC(Central Semiconductor Man-ufacturing Corporation)0.5μm CMOS(Complementary Metal Oxide Semiconductor)工艺,并利用0.5μm双层多晶硅三层金属的CMOS工艺实现了电路的版图绘制。仿真结果证明,变换器能稳定输出电压,并具有较小的电压纹波和较高的转换效率等优点。

基于双Boost交联拓扑的三相功率因数校正器

研究了基于双Boost交联拓扑的三相功率因数校正器,其主支路三相不控整流器通过外加并联功率因数校正电路来改善网侧电流波形,提高功率因数。首先对主支路的拓扑结构以及工作方式进行分析,总结该拓扑的特点,并针对其特点提出相应的控制策略以及参数设计方案。理论分析和仿真、实验结果表明:这种新型三相功率因数校正器适用于恒功率负载场合,只需通过控制从整流器的选相开关以及双Boost交联变换器即可获得稳定的6脉波直流输出电压、理想的功率因数以及总谐波畸变率,而仅有约1/5的功率经过双Boost交联变换器。

控制风力发电蓄电系统并联Boost电路

同步发电机在低风速时输出电压较低,无法达到蓄电池的额定电压值,因此,对一种适用于风力发电蓄电的带耦合电感并联Boost电路进行了研究。通过将耦合电感与Boost电路相结合,建立了控制风力发电蓄电系统电路。阐述了Boost电路的原理,设计了三段式充电电路的控制方法。Matlab仿真结果表明,相对于传统Boost电路,该电路很好地降低了输入电流的波纹,同时能够有效提高蓄电池的使用寿命。

Dual Boost PFC电路拓扑的研究

传统的Boost PFC电路的整流桥损耗是通信开关电源的主要损耗之一。无整流桥的拓扑更具有效率优势。由于无桥Boost PFC省略了整流桥模块,效率显著的提高。文中分析了一种高效率的Dual Boost PFC的大功率应用,通过实验证明了Dual Boost PFC电路效率比传统的Boost PFC提高1个百分点,还介绍了电阻采样控制电路的使用和如何降低EMI干扰。

A Voltage Sensorless Finite Control Set-Model Predictive Control for Three-Phase Voltage Source PWM Rectifiers

In this paper,a grid voltage sensorless model predictive control is proposed and verified by simulation and experimental tests for a PWM rectifier.The presented method is simple and cost effective due to no need of modulator and voltage sensors.The developed sliding mode voltage observer(SMVO)can theoretically track the grid voltage accurately without phase lag and magnitude error.Based on the proposed SMVO,the finite control set-model predictive control(FCS-MPC)is incorporated for power regulation.The active power and reactive power are calculated and predicted using the measured current and the estimated grid voltage from the SMVO.With the predicated power for one-step delay compensation,the best voltage vector minimizing the tracking error is selected by FCS-MPC.The whole algorithm is implemented in stationary frame without using Park's transformation.Both the simulation and experimental results validate the effectiveness of the proposed method.

基于LT8705的高性能buck-boost模块电源的研制

以Linear公司的LT8705为控制核心,针对宽范围直流输入、稳压输出用电设备的供电要求,研制了一款高性能的同步整流buck-boost模块电源。该模块电源集成了DC-DC单元、驱动电路单元、电压及电流环路工作状态反馈单元、电流控制功能单元,同时,对电路中的关键电路参数进行了计算。实验结果表明,该模块电源实现了预期功能,满足应用要求。

Simulation of multiphase boost DC-DC converter with the stable control strategy

The multiphase boost DC-DC converter with stable control strategy is presented. Multi- phase boost DC-DC converter is designed for high voltage and high power applications, and could be achieved by the adjustment of voltage doubler rectifiers on the secondary side of high frequency transformers. The stable control strategy for three phase boost DC-DC converter has been utilized during simulation in this study and this strategy can be extend to N-number of phases. The stable control strategy consists of only three voltage loops, which are sufficient for appropriate and efficient operation of three phase boost DC-DC converter. With the stable control strategy, the equal power balance sharing can be obtained between input and output. The stability of control strategy has been evaluated by simulating the multiphase boost DC-DC converter for the same and mismatch turn ratios of high frequency transformers. The simulation result is good and the objective of the strategy is a- chieved.

低压BOOST控制器ML4861及其应用

本文介绍用于DC-DC转换的低压型BOOST控制器ML4861的原理,工作特性和应用。并进一步讨论了电路设计中电感对系统效率,噪音等的影响。

锂电池低压逆变器前级升压设计

目前国内在低压逆变器方面的研究与工程应用相对较少,设计一台输出220 V、50 Hz稳定正弦波的锂电池低压逆变器,需要克服前级低压到400 V升压过程中出现的电路纹波过大、电流过大以及器件散热等问题。在电压变换电路、升压主电路和控制电路上,通过优化电路拓扑结构和PCB布线,辅助电源的纹波降低了23.1 mV;结合元器件的选择和研究,提出一种适用于锂电池低压逆变器的前级升压方案,通过调节反馈电路,将3.2 V的电压稳定地升压至400 V,用于3.2 V低压逆变器实物中。该设计方法对其他低压逆变的研究和应用具有一定的借鉴意义。

新型可变升压比18脉波自耦变压整流器研究

多脉冲整流器具有结构简单、效率高、可靠性强等优点,在航空领域有着广泛的应用前景。该文基于机载电子设备高功率因数和低谐波污染的要求,研究了一种输出直流电压可调节的新型18脉波自耦变压整流器,分析了其工作原理,详细推导了升压比例因子与输出直流电压、输入电流总谐波含量以及变压器等效容量之间的基本关系与变化规律,为系统的优化设计提供了理论依据。最后通过仿真和实验验证了理论分析的正确性。10 k V·A额定实验条件下,整流器功率因数为0.988,输入电流总谐波含量为7.36%,效率为98.7%,系统总重量为4.5 kg,其中自耦变压器重量为3.3 kg。

基于直通零矢量脉宽调制的Z源整流器研究

Z源整流器是一个特殊的阻抗网络,将变换器主电路和电源耦合在一起,获得独特的升/降压特性,有效地克服了传统的电压源和电流源变换器的不足。本文介绍Z源整流器的工作原理及其特点,在传统PWM调制基础上提出适用于Z源整流器的等分直通零矢量PWM调制方法,Simulink仿真证明了该调制方法的可行性,稳态和动态性能优良。