非平衡条件下矩阵式变换器输入电流偏置角恒定调制策略的仿真实现

介绍了输入非平衡的情况下矩阵式变换器的工作原理，研究了输入电流偏置角恒定的空间矢量调制策略并利用MATLAB建立了相应仿真模型，通过参数设定，相位计算，控制算法实现和开关接口电路，实现了非平衡条件下矩阵式变换器输入电流偏置角恒定调制策略，仿真结果验证了调制策略的正确性。     

矩阵式变换技术的发展综述

本文综述了矩阵式变换器的拓扑结构和开关元件的发展，阐述了矩阵变换器的调制策略，提出了矩阵变换器的最新进展与研究热点，展望了矩阵变换器的应用前景。     

矩阵式变换器空间矢量过调制策略研究

针对矩阵变换器调制策略电压传输比低的问题,在深入研究矩阵式变换器空间矢量调制策的基础上,提出了一种通过改变电压调制系数提高电压传输比的空间矢量过调制策略。根据电压矢量轨迹与空间矢量六边形位置的关系,将电压空间矢量调制区域分为线性调制区和过调制区,通过改变电压调制系数,从而实现过调制策略。最后建立MATLAB/Simulink仿真,结果表明空间矢量过调制策略可以有效提高电压传输比到0.955。     

双线电压调制MC输入/输出特性的仿真研究

在深入分析双线电压调制矩阵式变换器工作原理的基础上,采用理论推导和仿真实验相结合的方法研究了对称/不对称电网电压对矩阵式变换器输出电压及输入电流特性的影响。结果表明,无论电网电压对称与否,矩阵式变换器的输出电压均能达到期望值,但其输入电流在电网电压不对称条件下产生严重的畸变。文中结论对于改善矩阵式变换器的输入/输出特性具有一定的指导意义。     

矩阵变换器安全换流策略综述

矩阵式变换器是一种高效、节能、可靠、有发展前途的新型电力变换器,不需要储能元件,可实现能量再生。本文综述了矩阵式变换器的各种换流策略的优越性及不足,并简述了矩阵变换器换流策略的发展动态与研究热点。     

双级矩阵式变换器的输入功率因数控制

本文深入分析了双级矩阵式变换器的拓扑结构和调制策略。根据中间直流环节电压必须为正的原则,确定了输入功率因数角的调节范围。研究了输入滤波器对输入功率因数的影响,推导得出了网侧功率因数角的计算公式。Matlab仿真结果验证了理论分析的正确性。     

矩阵变换器的过调制方法研究及其仿真

针对矩阵变换器最大电压传输比仅为0.866的问题,研究了基于矩阵变换器输出电压空间矢量的两种过调制策略。文中将空间矢量调制控制区域划分为线性区和过调制区,过调制区又分为过调制Ⅰ区和过调制Ⅱ区。在过调制区中应用过调制策略,即将输入电流空间矢量调制与输出电压空间矢量过调制方法相结合。在调制策略中根据电压调制系数不同,选用不同的参考电压矢量调整策略来实现过调制。在Matlab/Simulink下分别对过调制策略进行了仿真研究,仿真实验结果表明过调制策略能够有效地提高矩阵变换器的电压传输比。     

矩阵式变换器安全换流策略研究

本文对矩阵式变换器的开关换流进行了分析,论述了四步换流策略的正确性和可靠性,并通过CPLD加以实现。仿真和实验结果表明四步换流策略可以使矩阵变换器中的双向开关换流安全可靠地进行。     

矩阵式变换器在变速恒频风电系统中的应用

本文首先对9开关矩阵变换器的工作原理以及控制方法进行分析,然后建立了矩阵变换器在d-q坐标系下的数学模型和矩阵式变换器实现变速恒频风力发电功率转换控制结构,并对矩阵式变换器实现变速恒频风电功率转换控制结构进行仿真,结果表明矩阵式变换器应用于变速恒频风力发电系统实现功率转换是可行的。     

双级矩阵变换器的过调制策略研究及实现

在分析双级矩阵变换器控制原理的基础上,提出了一种过调制控制策略,该策略分为两步:先改进双级矩阵变换器整流器的控制策略,使其整流侧得到尽可能大的直流整流电压,然后研究双级矩阵变换器逆变器的过调制控制策略,增大逆变器输出电压,从而实现电压传输比的提高,文中在过调制控制原理的基础上,基于DSP和CPLD建立了一套双级矩阵变换器实验装置,实验证明:双级矩阵变换器过调制策略能有效提高电压传输比,从而验证了该过调制策略的正确性.     

矩阵变换器双空间矢量控制法的仿真研究

矩阵变换器与普通交-直-交变换器相比有一些优异的性能。目前,在矩阵变换器的调制算法中,双空间矢量算法最为成熟,基于该调制法的矩阵变换器是交-交变换器研究中最具潜力应用于生产的理想变换器。文中论述了空间矢量法的原理,分析了双空间矢量调制策略,在Matlab/Simulink仿真平台上搭建了矩阵变换器模型并进行了仿真,以简单的阻感负载作为供电对象。仿真结果验证了双空间矢量调制策略的正确性和可行性,较明显地看出矩阵变换器与一般电力变换器相比的优点,也显示了矩阵变换器应用于工程实际的可行性。     

Bidirectional Switch Commutation for a Matrix Converter Supplying a Series Resonant Load

This paper describes a bidirectional switch commutation strategy for a three-phase to two-phase matrix converter supplying a series resonant load. Classical modulation techniques are not applicable because of the needed high output frequencies. This fact, together with the different topology compared to classical three-phase to three-phase matrix converters, makes a new investigation of commutation principles necessary. The paper shows that the three-phase to two-phase resonant matrix converter can be compared with the full-bridge series-resonant converter. Thus, the commutation of the full-bridge series-resonant converter gives the conditions for the bidirectional switch commutation at the matrix converter. One of the main benefits of the derived strategy is the minimization of commutation steps independent of the load current sign.     

Modeling and Simulation of Wind Energy Systems with Matrix and Multilevel Power Converters

This paper is concerned with modeling and simulation in Matlab/Simulink of wind energy systems with different topologies for the power converters: matrix converter and multilevel converter. We use pulse modulation by space vector modulation associated with sliding mode for controlling the converters, and we introduce power factor control at the output of the converters. Finally, we present the electric behavior for the power and the current at the input and at the output of the converters.     

Simple Unified Approach to Develop a Time-Domain Modulation Strategy for Single-Phase Multilevel Converters

Single-phase power converters are widely used in power applications as photovoltaics and fuel-cell power conditioners. In addition, multilevel converters are a well-known solution in order to achieve high-quality output waveforms in power systems. In this paper, a time-domain duty-cycle computation technique for single-phase multilevel converters named 1DM is presented. The proposed technique is based on geometrical calculations with outstanding simplicity and generality. The proposed modulation technique can be easily applied to any multilevel converter topology carrying out the necessary calculations. The most common multilevel converter topologies have been studied in this paper as examples to introduce the proposed modulation strategy. Any other multilevel converter topology could be studied, and the corresponding 1DM could be easily developed. In addition, the well-known optimized voltage balance strategy for voltage capacitor control using the redundant switching states of the system is applied working with the proposed 1DM method, showing that both techniques are compatible. Experimental and simulation results for several single-phase multilevel converters are shown to validate the proposed modulation technique.      

双向IGBT开关在矩阵变换器中的应用

双向IGBT模块是实现高频矩阵变换器极为有效的方法。略不同于硬开关PWM变换器，矩阵变换器中的开关和传导损耗取决于所选的调制策略。本文介绍了一种由诺丁汉大学推导的平均损耗的计算公式。测试一个使用1200V，200A的双向模块实现的三相到单相的构造，得到的波形说明了矩阵变换器的实际操作以及可能会出现的输出电流纹波。     

An improved DTC-SVM method for matrix converter drives using a deadbeat scheme

In this paper, a simple direct torque control (DTC) method for sensorless matrix converter drives is proposed, which is characterized by a simple structure, minimal torque ripple and unity input power factor. Also, a good sensorless speed-control performance in the low speed operation is obtained, while maintaining constant switching frequency and fast torque dynamics. It is possible to combine the advantages of matrix converters with the advantages of the DTC strategy using space vector modulation a deadbeat algorithm in the stator flux reference frame. Experimental results are shown to illustrate the feasibility of the proposed strategy.     

New time-discrete modulation scheme for matrix converters

While the known modulation strategies for matrix converters are based on pulsewidth modulation (PWM)-or vector modulation-this paper presents a novel time-discrete modulation method based on real-time prediction calculation to select the switching states. The decision about which switching state is to be set for the following sampling period is made by the use of a predictive quality function. Using this approach, unity displacement factor is seen at the supply side with minimum line current distortion while the load currents follow their reference values with good accuracy. The quality function is derived from a mathematical model of the matrix converter and the controlled system. Measurements taken on a model plant, consisting of a matrix converter and a standard induction machine with a rated output power of 11 kW, show that the matrix converter, equipped with the control method presented here, offers advantages over systems with conventional frequency converters, especially in terms of the input current distortion.     

A new modulation strategy for a buck-boost input AC/DC converter

This paper presents a novel modulation strategy for a power factor corrected (PFC), isolated AC/DC converter derived from the integration of a nonisolated, two switch buck-boost AC/DC converter with an isolated dual active bridge DC/DC converter (2SBBDAB). This strategy, termed discontinuous leading/trailing edge (DLTE) modulation, serves to maximize the duty cycle of the input switch while keeping the current in the buck-boost inductor discontinuous. Hence, the crest factors of the currents in the switching devices are minimized, the input switch is turned on at zero current and the zero-voltage switching ranges of the bridge switches are unaffected by the integration. A conventional isolated, PFC AC/DC converter typically consists of a boost converter cascaded with a forward converter. The ratings required of the power switching devices of the 2SBBDAB employing the DLTE modulation strategy are similar to those required of the conventional design for wide line voltage operation. However, the 2SBBDAB converter has higher line voltage surge immunity than that of the conventional design and, unlike the conventional design, it has inherent inrush current limiting. The DLTE modulation strategy may be applied to the family of converters composed of the two switch buck-boost integrated with half and full-bridge forward converters     

矩阵变换器双空间矢量调制策略的仿真研究

矩阵变换器是一种新型的电力变化装置,具有很好的应用价值,采取先进的控制手段对其进行调制是应用的基础。本文简述了矩阵变换器空间矢量调制原理,分析了输出线电压和输入相电流空间矢量调制以及矩阵变换器双空间矢量调制策略,给出了系统在Matlab仿真环境下的仿真模型和运行结果。仿真结果表明:基于双空间矢量调制策略的矩阵变换器具有良好的输入输出特性,为矩阵变换器进一步应用提供了前期检验和实验依据。     

A Multipulse-Structure-Based Bidirectional PWM Converter for High-Power Applications

Multipulse converters are suitable for high-power application with the merits of low switching frequency and perfect harmonic performance. But less controllability and poor regulation lead the restriction on its application. A bidirectional pulsewidth modulation (PWM) converter based on multipulse structure is proposed in this paper, which has the same perfect harmonic performance with very low switching frequency. A special sequential sampling space vector modulation technique, which has the sampling sequence from the lagging module to the leading module, is proposed to make the converter controllable like conventional PWM converters. The harmonic performance and linear regulation capability are analyzed theoretically. The converter is modeled in detail, and an instantaneous feedback control strategy with phase delay compensation and decoupling control is also proposed. The controller parameters are optimized to get high dynamic performance with adequate phase margin and gain margin. A 3-kVA prototype is built, and the simulation and experiment results validate that the proposed converter is quite suitable for high-power conversion.