新书介绍

<正>《永磁直流无刷电机实用设计及应用技术》是一本介绍无刷电机基本知识和理论,以及无刷电机、永磁电机实用设计的书籍,由邱国平、丁旭红先生编著,上海科学技术出版社出版。该书介绍了无刷电机的基本知识,站在新的角度介绍了无刷电机内部和外部特征,介绍了分数槽集中绕组和大节距电动机的相关内容,特别是对无刷电机的机械特性,主要常数和     

新书介绍

<正>《永磁直流无刷电机实用设计及应用技术》是一本介绍无刷电机基本知识和理论,以及无刷电机、永磁同步电机实用设计的书籍,由邱国平、丁旭红先生编著,上海科学技术出版社出版。该书介绍了无刷电机的基本知识,站在新的角度介绍了无刷电机内部和外部特征,介绍     

一款军用永磁直流无刷电机控制器的高可靠性设计

本文详细介绍了一款军用永磁直流无刷电机控制器的高可靠性设计。永磁直流无刷电机控制器在应用于航空、航天及武器装备等领域时对可靠性有着较高的要求,需对控制器进行高可靠性设计。本文通过实例详细介绍了军用永磁直流无刷电机控制器的高可靠性设计。     

介绍一种直流无刷电机专用芯片

本文介绍一种简单易设计的直流无刷电机专用芯片,以使大家更好的了解直流无刷电机。首先,大家要牢记:直流无刷电机必须把电机与电子线路紧密结合,就象单相异步交流电机中的定子与转子一样,缺一不可。而且,要先把电子线路掌握了,才能把电机设计得更好!1 介绍 ECN 3022 芯片     

一种抑制永磁直流无刷电机泵类负载停机反转的方法

介绍一种抑制永磁直流无刷电机泵类负载停机反转的方法.永磁直流无刷电机泵类负载在停机后发生反转会产生高电压,该电压将会对控制器与供电电源造成损伤.本文通过案列对永磁直流无刷电机泵类负载反转进行抑制的方案进行了详细分析.     

新书介绍

正《永磁直流无刷电机实用设计及应用技术》是一本介绍无刷电机基本知识理论和实用设计,以及永磁同步电机实用设计的书籍,由邱国平、丁旭红先生编著,上海科学技术出版社出版。该书介绍了无刷电机的基本知识,站在新的角度介绍了无刷电机内部和外部特征,介绍了分数槽集中绕组和大节距电动机的相关内容,特别是对无刷电机的机械特性,主要常数和目标参数进行了分析和介     

直流无刷电机电磁核算程序探讨

讨论了直流无刷电机电磁核算的特点,介绍核算的主要过程,并用VB6.0编制了直流无刷电机的核算程序,该程序具有良好的人机界面,大大缩短了电机设计的时间,提高了工作效率.     

MC33035在直流无刷电机控制中的应用

介绍了直流无刷电机和MC33035的芯片基本原理,并着重介绍了以专用控制芯片MC33035、MC 33039为核心构成的家用传动装置中永磁直流无刷电机控制器的设计,实现了以霍尔元件为速度反馈电路的双闭环无级调速系统驱动.     

永磁无刷电机转矩脉动分析及削弱方法

抑制转矩脉动是永磁无刷电机研究重点,国内外专家学者提出了诸多解决方法.在分析永磁无刷电机脉动转矩的组成及产生原因的基础上,综合介绍了削弱永磁无刷电动机转矩脉动常用的一些方法.     

智能功率模块PS21265在直流无刷电机伺服系统中的应用

介绍了基于智能功率模块（IPM）的直流无刷电机（BLDCM）伺服系统的设计原理和过程,侧重于智能功率模块PS21265在BLDCM控制系统中的具体应用,并分析了直流无刷电机的控制原理,并利用所建数学模型对直流无刷电机的控制系统进行了仿真,仿真结果表明设计达到了预期要求,电机起动快速、稳定,可靠性较好。     

旋转式倒立摆计算机控制系统

研究了一种新型的倒立摆系统,该装置是由连在直流力矩电机转轴上的驱动臂和能自由旋转的摆杆构成,驱动臂在电机的作用下能在垂直平面内旋转,能过驱动臂的转动来保持摆杆稳定在平衡位置,运用动力学原理建立了该系统的数学模型,在此基础上借助于计算机辅助设计软件,进行了仿真研究,设计出控制律,最后实现旋转式倒立摆计算机控制。     

"自控变频同步电机"系统中的交流电机是箝位电动机

针对直流电动机中电枢磁动势的轴线位置由电刷决定的特征,提出了箝位概念,指出自控变频乃是箝位效应的直接后果。对作为电机类型名称的"同步"一词之含义作了明确地阐述,同步电动机是无箝位电动机,稳定运行的同步电动机内频率与本机转速之间的因果关系是以恒定的频率为因。直流电动机是箝位电动机,箝位效应使直流电动机中频率与转速的因果关系颠倒成以易变的转速为因,直流电动机具有优良的控制性能以及无振荡的特性都与箝位的存在密切相关。"自控变频同步电机"系统中的电动机应是交流箝位电动机,而不是同步电动机。     

An impedance measurement of a small‐capacitance circuit using transient responses for lightning surge analysis

A method to measure a small capacitance with its loss resistance using a set of transient current waveforms is proposed in this paper. The parameters are obtained from the time constants in the time domain. The method has high resistance to extraneous noise, because a time‐to‐frequency transformation, which is sensitive to noise, is not required. The transient current waveforms are obtained by a voltage or current source, a current transformer, and a waveform recorder. The measured capacitance by the proposed method is not affected by the capacitance of the voltage probe, because it is obtained without any voltage information. The sheath surge impedance of the current injection cable, which is indispensable for the transient measurement, is corrected. The application of the method has the advantage in that it allows the modeling of a fast transient of a power apparatus, comparing it with the steady‐state measurement using an impedance measuring instrument. The proposed method is applied to create an equivalent circuit between electrodes implanted into a piece of wood, and its reliability is confirmed by comparison between the measured and calculated results. Stray capacitances of a miniature circuit breaker are also measured, and the results show that the proposed method is applicable to equipment in power systems. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

ac magnetic suspension using a differential feedback power amplifier

This paper proposes a new type of magnetic suspension system in which the electromagnet is magnetized by an ac current. The basic idea is a feedback of difference between the exciting current and the applied voltage. The feedback signal is applied to a power amplifier through two phase shifters and a bandpass filter. The usefulness is established by experiments on magnetic suspension. The main merit of this system is that stable suspension is achieved without a displacement sensor and without a self‐sensing controller. © 2000 Scripta Technica, Electr Eng Jpn, 131(2): 61–67, 2000     

Characteristics of Parallel Operation of Inverter‐Type Distributed Generators Operated by a Virtual Synchronous Generator

The capacity of distributed generators (DGs) connected to a grid by inverters is growing. The inverters are generally controlled by a phase locked loop (PLL) in order to achieve synchronization with the power system frequency. They cannot have synchronous power. Power systems become unstable if the capacity of the inverter‐type DGs is increased. The concept of controlling inverters to behave like a synchronous generator is studied in this paper. The result is referred to as a “virtual synchronous generator” (VSG). The VSG has synchronous power. Power systems become stable as a result of using the VSG. The VSG is useful in the parallel operation of DGs. The VSG can synchronize with other VSGs, synchronous generators, or the grid. In this paper, a method for the synchronous operation of a VSG is studied, and experimental results on a VSG running in parallel with a synchronous generator and other VSGs are presented.     

Extending the optimization of the rotating transformer brushless excitation to all rectifier modes

Brushless excitation of a synchronous machine has a significant advantage: no slip-rings are necessary. The rotating transformer method is investigated: the excitation machine is a wound rotor induction machine with controllable voltage supply on the stator side. The synchronous machine is excited by a diode bridge, connected to the rotor of the excitation machine. The operation of the system is essentially determined by the commutation of the rotating diode bridge. It has different rectifier modes in such a configuration (possibly long commutation process caused by the variable, possibly lower voltage; larger commutation inductance). With justified simplifications, a model is derived to investigate the operation. The classical converter theory is applicable for the variable voltage, variable frequency supply of the diode bridge. Optimal operation considering the utilization of the excitation machine is introduced, developed and extended to all rectifier modes. The result is a matching rule for the parameters of the system, which can be satisfied by complex design of the system elements.     

Robust method to provide exponential convergence of model parameters solving linear time-invariant plant identification problem

The scope of this research is a problem of parameters identification of a linear time-invariant plant, which (1) input signal is not frequency-rich, (2) is subjected to initial conditions and external disturbances. The memory regressor extension (MRE) scheme, in which a specially derived differential equation is used as a filter, is applied to solve the above-stated problem. Such a filter allows us to obtain a bounded regressor value, for which a condition of the initial excitation (IE) is met. Using the MRE scheme, the recursive least-squares method with the forgetting factor is used to derive an adaptation law. The following properties have been proved for the proposed approach. If the IE condition is met, then: (1) the parameter error of identification is bounded and converges to zero exponentially (if there are no external disturbances) or to a set (in the case of them) with an adjustable rate, (2) the parameters adaptation rate is a finite value. The above-mentioned properties are mathematically proved and demonstrated via simulation experiments.     

Active fault tolerant control of piecewise affine systems with reference tracking and input constraints

An active fault tolerant control (AFTC) method is proposed for discrete‐time piecewise affine (PWA) systems. Only actuator faults are considered. The AFTC framework contains a supervisory scheme, which selects a suitable controller in a set of controllers such that the stability and an acceptable performance of the faulty system are held. The design of the supervisory scheme is not considered here. The set of controllers is composed of a normal controller for the fault‐free case, an active fault detection and isolation controller for isolation and identification of the faults, and a set of passive fault tolerant controllers (PFTCs) modules designed to be robust against a set of actuator faults. In this research, the piecewise nonlinear model is approximated by a PWA system. The PFTCs are state feedback laws. Each one is robust against a fixed set of actuator faults and is able to track the reference signal while the control inputs are bounded. The PFTC problem is transformed into a feasibility problem of a set of LMIs. The method is applied on a large‐scale live‐stock ventilation model. Copyright © 2013 John Wiley & Sons, Ltd.     

Decentralized nonlinear H∞ controller for large scale power systems

The aim of this paper is to design nonlinear decentralized controllers for multi-machine power systems. The design procedure is based on H_∞ control theory and consists of two parts. First, the feedback linearization technique is used. Then, a robust controller is designed using the linear matrix inequalities (LMI) approach. The controller has two blocks. One, is a nonlinear function of some local measurable signals such as the generator active and reactive powers, the rotor speed and the armature current. The other block is a PID controller. The linear H_∞ theory is used to tune the PID parameters. The method results in a controller which is easy for implementing in practice. The performance of the controller is tested on a sample multi-machine power system model. Simulation results show the effectiveness, robustness and good performance of the proposed controller.     

Real-time economic dispatch and reserve allocation using meritorder loading and linear programming rules

The author presents a real-time economic dispatch algorithm suitable for online generation control and for study programs. The method is based on the rules of linear programming and the classical method of merit order loading. The basis for the algorithm is shown as a natural progression of classical optimization algorithms. Comparison with linear programming is included to exhibit the flexibility of the algorithm. The inclusion of a constraint for a unit or for a system-wide margin (e.g. spinning reserve) is shown. The procedure is fast, in part because the simplex tableau is not explicitly stored. The method is shown in pseudo-code. This method is very suitable for real-time economic dispatch on any energy management system. The method requires little computer resource and is appropriate for personal-computer implementation as part of a back-up automatic generation control system. The algorithm has been tested on data provided by Indianapolis Power and Light Company and has been programmed on a 80286 personal computer