一种新型稀土永磁无刷直流电机及其微机控制系统

提出了一种籍助于８０９８单片微机系统，通过控制永磁无刷直流电机各相电流的导通角来实现电机恒功率调速的方法，即移角控制方法，介绍了微机系统的软，硬件结构，并以一台基速为５００ｔ／ｍｉｎ，额定功率为１ｋＷ的电机为例，使恒功率调速范围扩展到四倍基速，证实了这种高速方法的有效性。     

多相感应电机的电子变极技术

传统感应电机构成的交流传动系统恒功率运行区间是有限的,为了使交流传动系统具有宽广的恒功率调速运行范围,在多对极多相系统变换理论的基础上,提出通过多相电机的电子变极实现宽范围恒功率调速.利用多相电机具有多个控制自由度的特点,通过多相电机转差频率控制产生不同平面的谐波电流,使电机在不同极对数的旋转磁场下运行,实现了在不停电情况下的电子变极.给出了9相感应电机3对极和9对极的变极实验,实验结果表明多相电机能够在不停电的情况下实现变极,从而可有效地拓宽恒功率调速运行范围.     

电动汽车用宽调速范围永磁磁阻电机优化设计研究

提出了一种能够在宽调速范围内实现恒功率运行的电动汽车驱动用复合转子结构永磁磁阻(CPMR)电机的最优设计方法.在交流永磁电机混合励磁机制分析的基础上,本文以逆变器电流定额最小为目标导出了在整个调速范围内实现恒功率运行的最优转子结构设计方案.设计样机的数值分析结果与IPM电机对比表明,该电机系统能够在很好地满足提供大过载转矩和宽调速范围运行要求的同时,具有较高的运行效率和功率因数.     

定子双馈电双凸极电机恒功率弱磁控制的研究

介绍了定子双馈电双凸极电机(SDFDS)的结构、原理和弱磁调速控制方法。相对于永磁电机,定子双馈电双凸极电机磁场可调,易于实现弱磁控制和基速以上的恒功率控制,大大扩大了电机的调速范围。针对一台三相12/8极定子双馈电双凸极电机,运用Matlab/Simulink软件建立仿真模型,实现该双凸极电机的恒功率弱磁调速,从而说明电机有调速范围更宽的优点。     

开关磁阻电机系统恒功率输出控制研究

介绍了开关磁阻电机系统恒功率输出控制的原理,给出了两种恒功率输出控制策略及其实施方案。实验结果表明,电机运行状态下采用开关角控制策略,发电运行状态下采用相电压控制策略,开关磁阻电机具有较高的系统效率和较小的相电流峰值。     

12/8极开关磁阻电机控制电路及软件设计

通过对三相12/8极开关磁阻控制系统的研究,以TMS320LF2407A为控芯片设计了36 k W开关磁阻电机的功率变换电路、过流保护电路及故障检测电路等;同时根据开关磁阻电机控制效果的要求,设计了双闭环控制调速结构,其中速度环采用分数阶PI调节器,并主要阐述了相电流斩波控制程序和电流调节器控制程序的设计。该系统针对硬件和软件方面的综合考虑,提高了开关磁阻电机调速系统的稳定性和可靠性。     

基于PLC的掘进机恒功率变频调速系统仿真分析

悬臂式掘进机在工作过程中负载随机变化且变化幅度较大,以PLC为控制核心,构建自适应模糊控制的掘进机恒功率变频调速系统,根据截割电机电流的偏差变化及变化率,采用模糊推理和自适应调节进行变频调速控制,实现掘进机截割电机的恒功率控制,采用MATLAB/Simulink软件进行仿真分析,结果表明,基于PLC自适应模糊控制的掘进机变频调速系统能够更好的进行掘进机的恒功率控制,提高了系统的稳定性.     

一种新型电动车用宽调速永磁电机驱动系统

介绍了一种新型电动车用永磁电机宽调速驱动系统。在采用新型电机结构的基础上．基于标量算法的快速电流追踪控制满足了高性能的调速要求。在高速下．利用变压器电势来削弱电机旋转电势。从而实现了高于基速的恒功率运行．扩展了电机的调速范围。     

笼型三相异步电动机变极调速和变频调速解析

主要讲述笼型三相异步电动机变极调速和变频调速的特性。重点对变极调速电机恒功率和恒转矩调速的接法和特性,变频调速电机设计特点,基频以下和基频以上调速时对应的恒转矩和恒功率调速特性进行阐述和分析,从而指出两种调速电机的特点和发展趋势。     

开关磁阻电机新型功率变换器的研究与设计

分析了常用的开关磁阻电机公共开关型功率变换器主电路,对续流阶段相电流的影响因素进行了理论分析,说明了续流时间的长短直接影响到系统的输出转矩和转矩脉动。为了提高系统重载和高速时的调速性能,给出了几种新型的功率变换器主电路。仿真结果说明改进的新型功率变换器加速了绕组放电,缩短了续流时间,改善了电流波形,降低了转矩脉动,并提高了系统的输出功率。     

利用电流故障特征的大功率整流装置故障在线诊断方法

针对大功率整流装置单管直通、开路及单相交流进线开路等三种单元件故障,分析了故障电流特征,提出了一种根据电流故障特征在线诊断故障的方法。单管直通时,根据计算得到的直流电流理论值将大于直流电流实测值,且故障相与非故障相的直流分量符号相反,可确定故障元件所在相别,再根据故障相直流分量正负可确定故障元件所在共阳或共阴组别。对单管开路和单相交流进线开路,若滑窗计算得到相电流直流分量持续大于某一整定值时判定为单管开路故障,再通过直流分量极性确定故障元件所在组别;若相电流直流分量先增大超过某一整定值后再减少至0,判定为单相交流进线开路,根据故障相电流基波幅值最小确定开路相别。仿真结果表明,该方法可快速诊断出故障,适用于多重化并联整流电路的故障诊断场合,具有一定的理论与实用价值。     

变压器合闸抑制冲击电流及分断无弧的控制线路

本文提供的控制线路,采用晶闸管,使空载单相变压器在最佳相位角下合闸,以抑制冲击电流,稳态时随即用接触器触头短接晶闸管,转换工作电流。分断时,触头刚分断即令晶闸管导通,转移工作电流,使触头无电弧分断,随即晶闸管自然关断。接通和分断变压器,晶闸管都是瞬间工作,故可选用小电流容量的管子。     

A Comparative Study of Symmetrical Three-Phase Circuits for Phase-Controlled AC Motor Drives

The speed of an induction motor in certain types of drives can be adjusted by phase control of the applied voltage. Three pairs of inverse-parallel thyristors are required for three-phase bipolar symmetry, but several different arrangements of the thyristors and motor windings are possible. A direct series connection of thyristors and windings in each phase can be made; the three phases can then be connected in delta, wye, or wye with neutral return. Alternatively, a delta connection of thyristor modules can be inserted in the opened neutral junction of wye-connected windings. Representation of the motor as a counter EMF in series with leakage reactance allows a simplified analysis of the current waveforms in terms of the thyristor conduction angle. With a given fundamental current, the current harmonics in the motor windings and in the supply lines for each of the circuits can then be compared. The results are equally applicable to thyristor-controlled inductive loads such as may be used for reactive power adjustment.     

Control of wound rotor induction motor using thyristors in thesecondary circuits

An investigation was made of three-phase induction motor operation in the presence of a thyristor-controlled resistive network in each rotor circuit. The experimental realization of the drive posed some serious problems, notably with regard to the successful firing of thyristors over a wide speed range. Motor performance characteristics of output power, stator current, power factor, and efficiency were obtained as functions of speed over the entire range of thyristor firing-angles. An equivalent circuit is used based on the single-phase equivalent of a balanced, sinusoidal three-phase system. Such an equivalence is not directly justifiable because the per-phase performance of the nonlinear, thyristor controlled star-connected load is not the same as that of the corresponding single-phase circuit. Proof of the appropriateness of the chosen equivalent circuit approach is in the high level of agreement between the measured and calculated performance characteristics. The effective value of the external rotor “resistance” was calculated using the principle of power invariance. This resistance value proved to be a function of the motor speed and thyristor firing-angle as well as of the resistor values, for the configurations investigated. Analysis of the external network was extended to calculate the total input “impedance” (i.e., voltage/current ratio)     

New DC Chopper Circuits Using Fast-Switching Reverse-Conducting Thyristors for Low-Voltage DC Motor Control

Fast- switching reverse-conducting thyristors have been developed and used in dc chopper apparatus to control the speed of highvoltage dc traction motors. The newly developed dc chopper circuit and its application for low-voltage dc motor control are discussed. The fast-switching reverse-conducting thyristor is utilized as the main thyristor to control load current.     

电动车无刷直流电动机驱动电路及其速度控制

结合西安微电机研究所为电动轨道车变速驱动设计的三相无刷直流电动机及其控制装置,介绍一种电流为半正弦波方式的驱动电路及由线路实现的电机速度检测。采用乘法器原理将换相逻辑、电流波形和速度环控制的电流幅值等信息综合,实现由ＭＯＳ等ＰＷＭ调制、速度闭环和电流滞环控制的无刷直流电动机驱动电路。该电路结构简单、成本低廉,实用于一般要求的变速驱动。     

可控硅双闭环直流调速系统的研制

直流调速系统是自动调速控制系统的主要形式。该系统以可控硅三相桥式全控整流电路构成系统的主电路,采用同步信号为锯齿波的触发电路。为了获得良好的动、静态品质,在充分利用电机过载能力的条件下获得最快的动态响应,整个系统采用电流、速度双闭环的控制结构。     

System Design Method for a Load Commutated Inverter-Synchronous Motor Drive

In a thyristorized load commutated inverter synchronous motor drive system, the inverter relies on the back EMF of the synchronous motor to provide the reverse voltage for commutation. The level of the back EMF is a function of both the synchronous motor's field current and rotational speed. The inverter operating frequency is determined by the motor speed and number of pole pairs. For a fixed thyristor firing angle, an increase inmthe level of armature current decreases the available thyristor turn-off time due to overlap of the incoming and outgoing thyristor. This overlap time is a function of the commutating reactance of the synchronous motor. These factors, field current, motor speed, inverter frequency, and armature current, together with a thyristor turnoff time specification, set a maximum limit on the value of motor commutating reactance. The motor designer and inverter designer must perform a tradeoff study of these factors to arrive at a satisfactory drive system. The results are presented of an analysis that allows the synchronous motor reactance to be specified based on the other given parameters of the inverter-synchronous motor drive system. Test data are provided from a 20-kVA 500-1000 Hz load commutated inverter/ inductor type synchronous motor drive system. The effects of motor speed and field excitation on the operating condition of the drive are discussed.     

The Performance of a Single-Phase Current-Fed Inverter with Counter EMF?Inductive Load

Current-fed inverters that have series diodes to trap the charge on a commutating capacitor can supply ac loads of any power factor. A single-phase circuit with counter emf-inductance load, such as a motor, has been analyzed by digital computer simulation, valid for all modes of operation. The magnitude and phase of the ac load current are graphically related to the direct current and thyristor firing angle with respect to the counter emf. The ratio of the operating frequency to the natural ringing frequency of the commutating capacitance and the load inductance is a parameter of the circuit that significantly affects its behavior. Problems associated with high-frequency operation in a drive system are discussed.     

A Microprocessor-Controlled Fast-Response Speed Regulator with Dual Mode Current Loop for DCM Drives

A new control method is described in which a microprocessor is used to regulate the speed of a dc motor driven by antiparallel-connected three-phase dual thyristor converters. A distinct feature of this speed regulating system is that speed response is improved by using a fast-response current controller for the internal loop. A fast-response current controller is obtained by employing a nonlinear compensation subloop and a proportional plus integral compensation subloop. The nonlinear compensation subloop is used to linearize the nonlinear load characteristics of the thyristor converter, which are encountered under discontinuous conduction states of current. The proportional plus integral compensation subloop reduces the deviation of detected current from the current reference. With these two current-control subloops a fast motor speed response is achieved under discontinuous as well as continuous conduction states; hence the steady-state accuracy of speed is improved. A speed regulator using a microprocessor was trial manufactured and tested with a 20-kW dc motor. It was found that an extremely fast controlled current response can be obtained even with a relatively long sampling period. Further, normal action was confirmed in four-quadrant operation.