基于双变量控制的交交变频调速系统特性研究

目前,煤矿风机、泵类负载的节能和扩容改造,是我国煤炭行业普遍存在和亟待解决的两个问题,文章在分析传统单变量控制原理缺点的基础上,引出了双变量控制原理,分析了交交变频器的自然无环流运行方式,优化了双变量控制下的输出电压波形:并把双变量交交变频器的应用扩展到双馈调速领域,检验了双变量交交变频器的运行效果,扩大了其应用范围。     

无刷双馈风力发电控制策略研究

本文研究了为实现最大风能捕获和有功、无功功率解耦控制的无刷双馈发电机的定子磁链定向矢量控制策略,并建立了变速恒频双馈风力发电系统的仿真模型,通过仿真验证了理论、模型和控制策略的正确性、可行性。     

SL150交-交变频调速系统在BD轧机中的应用

交-交变频调速系统具有高转矩和低转速的优点,曾广泛应用在钢铁行业、采矿行业和轮船驱动上,其结构简单,可靠性高。本文结合日照钢铁H型钢厂BD轧机传动系统改造项目,介绍了交-交变频调速传动系统的组成、SL150变频器结构和控制功能,并简单介绍了SL150系统的安装调试的关键事项,为以后的故障判断和处理提供依据。     

微特电机

0600290 笼型转子无刷双馈电机d-q模型与控制特性仿真[刊, 中]／黄靖／／海军工程大学学报．-2005,17(5)．-86- 91(G) 无刷双馈电机是一种新型的适于变频调速系统使用的电机,其结构型式和工作原理与传统交流电机相比具有较大的区别。针对转子结构为笼型短路绕组的     

双馈感应风力发电机直接转矩控制的研究

直接转矩控制技术已经广泛应用于感应发电机的调速控制领域,并已取得良好的控制效果,而双馈风力发电机的直接转矩控制主要工作在低频区域,并且它的低频特性是一个研究热点。文章对变速恒频双馈风力发电机直接转矩控制进行了理论分析,阐述了它的工作原理结构,推导出具体的控制方程,并对它进行仿真,结果证明双馈感应风力发电机直接转矩控制在风力发电系统中具有利用率高,并网冲击小,并网速度快的优点。     

风电系统中发电机励磁控制系统的研究

论文介绍了风电系统中双馈风力发电机（DFIG）的工作原理,论文中所提出的双馈风力发电系统主要采用了双PWM换流器结构的交流励磁系统。并运用矢量控制的控制策略对网侧变换器和励磁侧变换器进行控制。并通过Matlab软件构建了最大风能追踪的仿真模型对其进行仿真,仿真表明论文中所提出的控制策略能够实现现风力发电系统的最大风能追...     

基于垂直轴双馈风力发电系统的仿真研究

以垂直轴风轮（VAWT）和双馈感应发电机（DFIG）为研究对象,建立了包括风力机模型、传动系统模型和双馈电机模型的垂直轴双馈风力发电系统的数学模型及结构,采用双馈电机定子磁链定向前馈解耦控制,使得电机的有功分量和无功分量可以分别得到控制。运用Matlab/Simulink建立了系统仿真模型,对定子磁链定向前馈解耦控制策...     

低容量可逆调速系统设计与仿真实现

低容量可逆调速系统设计即为"电流与转速双闭环直流调速系统的设计",长期以来,直流电动机因其具有调节转速比较灵活、方法简单、易于大范围内平滑调速、控制性能好等特点,一直在传动领域占有统治地位。通过设计仿真,提出可逆系统的设计,并仿真实现符合参数要求,建立模型和仿真平台。得出双闭环调速系统比起单环系统更稳定。     

交—交变频器在矿井提升机中的应用

正电力电子器件的制造技术迅速发展为交流调速技术的发展奠定了极为有利的技术条件和物质基础,不但使交流电动机调速系统的调速性能可以同直流电动机相媲美,而且成本和维护费用比直流电动机系统更低,可靠性更高。目前,先进的工业国家生产直流传动装置己呈下降趋势,而交流变频调速装置的生产大幅度上升。因此,采用高效率经济型的交流调速系统来取代原有的直流电动机调速系     

数字控制交-交变频调速技术在热连轧机中的应用

轧机的电机功率大，干扰严重，其调速精度难以控制．文章提出的数字控制调速技术先进、可靠，解决了上述问题。变频对电网的谐波采取了滤波措施。对于变频调速的设计应用具有很大参考价值。     

A fully integrated CMOS direct-conversion transmitter front-end for WiMAX

A naturally commutated six-pulse cycloconverter working in the inverting mode is used to feed power to a single phase AC motor at 400 Hz. The motor is connected at the input side of the cycloconverter while the three-phase mains is connected at its output. Three-phase mains feeds power to the input side of the cycloconverter which is arranged as a tuned load at 400 Hz. The effect of the single-phase induction motor on system performance is discussed. The principle of voltage and frequency control for proper operation of the induction motor is presented. The results are experimentally verified.     

Microprocessor Control of Cycloconverter: Techniques for Implementation and Testing

Since the 1930's, cycloconverter control circuits have been designed with vacuum tubes, transistors, and integrated circuits. With the advent of microprocessors, much more logical and computational power became available in much less space and cost. This led to the design of converter control circuits using microprocessors [2]-[9]. Each of these papers describes a specific implementation. Advancements in microprocessor technology are still going at full steam. To take full advantage of this technology and its continued advancements, a systematic and broad-based study of techniques that can be used for cycloconverter control-on microprocessor-based systems-is required. This paper reports the findings of such a study [10]. In this study a few general techniques were developed for cycloconverter control. In developing the various Techniques, accuracy of trigger timing and the system's speed of response were used as performance criteria. The techniques developed were tested on a system based on the 8085 CPU. Each technique was tested qualitatively by recording the cycloconverter waveforms produced by using it. For quantitative testing, first, the theoretical trigger timings were found by a digital computer simulation of the cycloconverter. These timings were then compared with those produced on the microprocessor-based system. From the test results it was concluded that an 8 bit data width suffices for cycloconverter control. The main bottleneck in achieving the desired performance is the execution time of the processor. In one of the techniques, when improvement in trigger timing accuracy was achieved it lead to reduction in the speed of response.     

一种低成本单相-三相周波变换器的研究

本文提出一种适用于异步电机传动的单相-三相周波变换器。应用一种基于开环恒压频比控制的离散跳频起动策略,实现了电机的良好起动特性,同时保证了低频阶段降低起动电流而保持足够大的起动力矩的目标。由于仅采用7个晶闸管,该周波变换器-电机传动系统具有造价低,结构简单的特点。仿真及实验结果表明了该控制策略的有效性以及系统方案的可行性。     

Input current harmonic analysis of pseudo 12-pulse 3-phase to6-phase cycloconverters

A general analytic approach is presented for input current harmonics in a pseudo 12-pulse 3-phase to 6-phase cycloconverter system. The results can be used to predict the existence or absence of a particular frequency component in the input current of such systems under both symmetrical and asymmetrical operating conditions. A quantitative relationship is established to estimate the amplitudes of the harmonics based on the analysis of a typical 6-pulse 3-phase to single-phase cycloconverter     

An efficient algorithm for the control of a microprocessor-basedsingle-phase to three-phase cycloconverter

An efficient algorithm is designed to calculate the intersection points of a cosine wave and a reference wave in a cycloconverter. The proposed algorithm requires a smaller number of comparisons to calculate the required intersections than the conventional linear search method; hence, processor time is reduced. The algorithm can be implemented on a microprocessor-based cycloconverter multiple feedback system. The reduced number of comparisons as compared with the linear search method make the algorithm useful for many applications in microprocessor-based control circuits     

Modeling and simulation of a cycloconverter drive system forharmonic studies

This paper discusses the steady-state harmonic modeling and simulation of a cycloconverter drive system (CDS). The operation and control of a cycloconverter drive and a synchronous motor load were modeled in the time domain. Based on the duality principle of electric and magnetic circuits, four types of three-phase transformer models with detailed nonlinear magnetizing characteristics were implemented. The harmonic behaviors of the entire system were studied under several worst operation conditions. The goal of this paper is to understand the harmonic problems associated with a CDS from an integrated system point of view, with special attention given to harmonic filtering and cancellation effect of converter coupling transformers     

Microprocessor Control of a Cycloconverter

This paper examines in some detail the problem of controlling a single-phase cycloconverter using a multimicroprocessor system. The cycloconverter must operate with a frequency- and voltage-wild input waveform. A new control scheme based upon input areas has been devised to enable successful operation under such circumstances. Both the hardware and software aspects of the microprocessor controller are described, including details of the area algorithms.     

Experimental Study of a Soft-Switched Isolated Bidirectional AC–DC Converter Without Auxiliary Circuit

An isolated ac-dc converter topology includes a capacitively snubbered voltage source converter (VSC) and a cycloconverter, coupled by a medium frequency transformer. The topology offers the possibility of bilateral power flow as well as three-level pulse width modulation on the ac side. It is shown that by alternately commutating the VSC and the cycloconverter it is possible to achieve either zero-voltage or zero-current switching conditions for all semiconductor devices in all points of operation. This is the case without any need for auxiliary semiconductor devices. At low load the transformer current may be insufficient for recharging the VSC snubber capacitors. In this case, however, it is possible to utilize the cycloconverter for providing a current path by which a quasi-resonant commutation can be made. The design and operation of a 40-kVA prototype converter system is described. It is shown how the rather complex switching logic required for implementing the chosen algorithm for commutation and modulation can be realized by using modern programmable logic devices [field programmable gate array (FPGA)]. Measurement results from the prototype converter are presented and analyzed. The measurements indicate that the studied commutation algorithm works well in practice     

热连轧交交变频全数字矢量控制系统故障处理与改造

本文着重叙述了我厂主传动交交变频系统控制装置的构造及其功能,另对一些常见故障进行介绍和分析,并列出一些成功改造试点,供大家参考。