Several control strategies used in shunt active power filters such as triangular carrier waveform control 、 hysteresis - based current control 、 instantaneous current control under fixed frequency have been researched , and the characters of them have been gained through these analysis 对并联型有源电力滤波器的三角波载波线性控制、电流滞环跟踪控制、定频瞬时值控制等电流控制策略进行了研究,通过理论分析比较了各自的特点。对采用ip
The nonlinear problem is ubiquitous and is difficult to solve in electro - hydraulic servo system . it is caused by the throttling property , because of the existing of the servo valve , proportion valve and throttling valve , by the dead band , the back lash and so on 非线性是电液伺服系统中普遍存在且至今没有很好解决的问题,这些非线性主要由电液转换和控制元件(伺服阀、比例阀或节流阀)的节流特性和液压动力机构的滞环及死区等因素引起。
This paper presents a novel single phase aeronautical static inverter . a novel combining two - transistor forward converter is presented and applied in the front of three - level hysteresis current controlled inverter , and a single - phase 6kva aeronautical static inverter is developed 本文介绍了一种新型的单相航空静止变流器，电路通过一新颖双管正激组合式变换器作为三态滞环控制电流型逆变器的直流输入前级，成功研制出6kva单相航空静止变流器。
This paper makes the feasibility design and study of the dtc ( direct torque control ) system based on analyzing some important parts , such as the arithmetic model of asynchronous motor in - coordinates , the choice of voltage vectors , and flux - linkages models , etc . the research work in this paper is described as follows : 1 analyzing of the dtc theory : material about the development and theory of dtc , the composing of dtc - system are presented in this paper 本文在详细分析了定子坐标系下的异步电动机数学模型、电压空间矢量和磁链观测器的基础上，利用直接转矩控制技术，构建了基于dsp的直接转矩控制系统。论文的主要工作包括以下三个方面： 1直接转矩理论分析研究：针对直接转矩控制理论在低速范围转矩观测器和转速波动等问题，采取了滞环模式切换，矢量细分等改进措施。
Because electro - hydraulic servo system has lag circle 、 dead zone 、 nonlinear tache , and difficult to ascertain the precise mathematic model , fuzzy control test system was designed to overcome the system disadvantage , the design method of fuzzy cotroller and the implementation of computer fuzzy control software were all proposed 摘要针对电液伺服系统中往往存在死区、滞环等非线性环节，很难建立精确的数学模型等特点，设计了一个模糊控制测试系统，克服了系统的缺点，给出了模糊控制器的设计方法和计算机模糊控制软件实现方案。
Adopting rotor field - oriented vector control methods , through which make the stator and the rotor magnetmotive forces can be kept orthogonal all along during operation of the bldcm , combining hysteresis current modulation ' s current control advantage and space voltage vector modulation ' s torque ripple attenuation advantage , then designing a sort of bldcm hysteresis current svpwm control method 摘要研究采用转子磁场定向的矢量控制方法使无刷直流电动机定、转子磁势矢量始终保持正交，结合滞环调制电流控制和空间电压矢量调制，设计了无刷直流电动机滞环电流svpwm控制方案。
The controller includes two control loops which are outer speed loop ( variable parameter pi adjustment ) and inner current loop ( single - chop current delta - control ) . in order to improve system performances , design of digital control system based on dsp is presented . the proportional parameter and integral parameter can be obtained through the design 整个系统采用变pi参数转速调节(外环)与单斩电流滞环调节(内环)相结合的双闭环控制方式,为了得到既快速又稳定的恒速系统,本文还给出了基于dsp的双凸极永磁电机数字控制系统的设计方案,通过此设计方案可以得到转速环的比例参数kp和积分参数ki的参考值。
In the simulation system , the performances have been analyzed when the parameter of torque hysterelic comparator or the hysteretic band of stator flux is changed . the simulat ion of switching between hexagon flux control and circle flux control is also compl eted . in addition , the traditional pi regulator is improved in the paper 在仿真中分析了转矩滞环和磁链滞环参数的变化对系统控制性能的影响，并且对两种控制方法在基速范围内的切换进行了仿真研究，同时在仿真中采用积分分离式pi调节算法对传统的pi调节器进行了改进。
In order to avoid the current ripple and the high switch frequency of fixed - band hysteresis current controllers , two hysteresis controllers of change hystersis - band are proposed . one is the sinusoidal - band hysteresis current controller , the other is the adaptive hysteresis current controller based on fuzzy theory 由于常规的滞环电流控制器不能有效地防止负载电流脉动，并且存在着容易导致逆变器的开关器件的开关频率过高的问题，论文提出了两种变环宽滞环电流控制器结构，其一是正弦环宽滞环电流控制器，其二是模糊变环宽滞环电流控制器。
People can easily design the hysteresis current control hardware circuit , but the switching frequency is variable which makes us difficult the design the output filter , moreover the output waveform is not good . the space vector modulation techniques , by selecting the zero vector properly , it can reduce the harmonic content of the output voltage , so it has become a popular control method 滞环电流控制的硬件电路设计简单,但存在开关频率不固定,输出滤波器设计困难,输出波形质量差,空间矢量控制( svm )技术具有较高的电压利用率,且通过对零矢量的合理控制可以降低谐波含量或降低开关损耗,因此是一种较好的控制方法。
