A New Rapid Nonlinear Simulation Method for Switched Reluctance Motors

This paper presents a new rapid nonlinear simulation method for switched reluctance motors (SRMs). An exact mathematical relationship among the magnetization curves of an SRM is obtained by curve fitting the variable parameters in the Torrey model. Only geometry-based requirements are taken as input needed. Since complete magnetic characteristics are not necessary, a lot of preliminary measurements and calculations are eliminated. The dynamic performances under two operating conditions are predicted using the proposed method, and the measured results are obtained by an experimental laboratory setup. Furthermore, predictions using other two traditional models are presented for the purpose of comparison. Experimental and simulation results verify the accuracy and rapidity of the proposed method.      

Piezoelectric Actuator Design and Placement for Switched Reluctance Motors Active Damping

This paper describes the design and the placement of piezoelectric actuators on switched reluctance motors by means of a genetic algorithm (nondominated sorting genetic algorithm II) for the purpose of reducing stator vibrations. Two distinct approaches are presented: one energy-related and the other based on a minimization of the resultant displacement. These methods lead to design and placement strategy for the piezoelectric actuators. A number of optimal actuators obtained using these kinds of approaches is also compared with mechanical finite-element simulations. At last, a solution is achieved in order to validate optimal placement using positive position feedback active filtering.      

非对称中点钳位型逆变电路的开关磁阻电机模型预测直接转矩控制方法

针对开关磁阻电机(SRM)转矩脉动过大的问题,提出一种非对称中点钳位型逆变电路的模型预测直接转矩控制方法,该控制方法基于开关磁阻电机的电感特性及转矩产生原理对扇区进行重新划分,对非对称中点钳位型逆变电路的基本工作模式进行分析并选取基本电压状态,根据直接转矩控制原理及扇区实际意义制定新型矢量选择方案,减少每个控制周期中的...     

Efficiency Improvements of Switched Reluctance Motors With High-Quality Iron Steel and Enhanced Conductor Slot Fill

In this paper, a comparison of efficiencies is put forward for a set of test machines constructed from several different types of low-loss magnetic steels. These are laminated amorphous alloys, 6.5% high silicon steel, and general-purpose low-loss silicon steel. Efficiency and characteristics are compared by experiment. The test switched reluctance motors are shown to have more than 95% efficiency at an output of about 2 kW. The effectiveness of an enhanced winding slot fill factor is also evaluated. The use of the high silicon steel is more practical at improving the efficiency as opposed to the use of increased slot fill factor.      

基于模糊控制的新型永磁开关磁阻电机控制系统研究与设计

提出了一种新型永磁式开关磁阻电机。通过对传统电机结构上进行了改进,在定子上加入永磁材料,使得电机成为混合励磁电机,分析了其结构及原理等,并探讨了其调速方式,把模糊控制运用于调速系统,设计了其调速系统的软硬件,最后对其样机进行了试验,对开关磁阻电机的改进具有一定指导意义。     

Semiactive and Active Piezoelectric Vibration Controls for Switched Reluctance Machine

This paper presents two vibration control approaches using piezoelectric inserts applied to a switched reluctance machine (SRM) in order to reduce acoustic emission. The semiactive approach, called synchronized switch damping, consists of a particular voltage processing that increases the electromechanical energy conversion of the piezoelectric insert and leads to effective vibration energy dissipation. Piezoelectric inserts can also be considered as actuators: the active technique aims at imposing an adequate force in order to compensate the structure strain originated by the electromagnetic forces. These two techniques are compared on a single-phase structure mechanically similar to that of an SRM. Advantages and drawbacks depending on the chosen technique are then discussed.     

功率变换器叠层母排优化设计

以60kW开关磁阻电机系统中采用三相不对称半桥电路的功率变换器为例,设计叠层母排方案,通过电路仿真,研究各部分杂散电感对电路瞬态特性的影响。分析母排设计中各几何因素对杂散电感影响,引入影响因子,对母排设计中各因素的影响程度进行评估。据此,为母排最优设计提供依据。     

A Position Stepping Method for Predicting Performances of Switched Reluctance Motor Drives

This paper presents a novel numerical method, which will be referred as the position stepping method (PSM), to predict the performances of switched reluctance motor (SRM) drives. The 2D bicubic spline is employed to generate the finite rectangular elements. The 2D bilinear spline is used to model the nonlinear magnetic characteristics in SRMs. Consequently, the conventional nonlinear first-order differential voltage equation for describing the performances of SRM drives can be simplified into an analytical expression in terms of the current with respect to the rotor position. Furthermore, the position stepping algorithm is developed according to the boundary and continuity conditions, to accurately and rapidly compute the current from the proposed current expression. Simulated and measured current waveforms are reported to validate the developed PSM. The CPU execution time required by the PSM compares very favorably with that of the analytical method. Overall, this paper provides an accurate and speedy approach to predict the currents and torques of SRM drives.     

Online and Offline Rotary Regression Analysis of Torque Estimator for Switched Reluctance Motor Drives

A new torque estimator for switched reluctance motor (SRM) drives based on 2-D rotary regression analysis is presented in this paper. The proposed torque estimator is composed of a bicubic regressive polynomial as a function of rotor position and input current. The regressive coefficients can be computed offline or online from the torque characteristics acquired either experimentally or from numerical computation. Furthermore, a torque estimation method by taking mutual coupling into consideration is proposed. It can be seen that the estimated and experimentally obtained self-coupling and mutual-coupling torque characteristics are in good agreement with each other. In addition, the dynamic torque waveforms with and without the mutual coupling, estimated by the proposed estimator, are found to be virtually the same as those obtained from the bicubic spline interpolation for SRM drives with single-pulse voltage, hysteresis current chopping, as well as with voltage pulse width modulation control. The success of all the case studies being reported is a good validation of the usefulness and accuracy of the proposed real-time torque estimator that, as described in this paper, can be used to quickly estimate the instantaneous output torque of SRM drives.     

变频电机驱动轴系扭矩脉动特性试验研究

为研究变频电机扭振机理,采用信号分析方法建立了变频电机SPWM运行模式下扭矩谐波特性分析模型,在变频电机驱动轴系试验台上开展了升速过程中扭矩特性试验研究.结果表明:变频电机不仅会产生转速的多阶整数倍频分量,在转速频率附近也会产生若干间谐波分量,随着分量阶次的升高,相应阶次分量的幅值减小;弯曲振动对脉动扭矩的影响较小;随着转速的升高,扭矩脉动幅值越来越大;扰动情况下,脉动扭矩中出现了大量杂频分量,幅值较无扰动时大.     

三相异步电机弱磁控制策略研究

基于异步电机矢量控制弱磁方法,探讨了传统1/ωr方法、考虑转矩电流分量改进型的1/ωr弱磁方法和基于电压控制策略的转矩最大化弱磁方案,并对比分析了三种弱磁策略的关键控制量的仿真波形,同时比较验证了弱磁控制策略的有效性,以供工程应用.     

Adaptive Dynamic Surface Control of Nonlinear Switched Systems with Prescribed Performance

This paper studies the adaptive control problem for a class of switched nonlinear systems with guaranteed prescribed performance bounds under arbitrary switchings. The unknown system functions are approximated by radial basis function neural networks. We employ dynamic surface control technique to solve the explosion of the complexity problem. We control the transformed system such that it is stabilizable, by this way, the original system is stabilizable as well as the prescribed performance is guaranteed. The proposed controller and update laws guarantee the stability of the closed-loop system and the boundedness of all signals. Furthermore, the prescribed performance is ensured. Finally, a simulation example is employed to illustrate the effectiveness of the proposed method.     

汽油机瞬态工况点火系统的优化控制

应用微机技术,使汽油机在非爆震区根据发动机的转速和功率由开环控制系统自动寻找点火角度;而在爆震区,则由闭环控制系统对其跟踪调整,至微爆状态。这样,发动机在稳态和瞬态运行都能实现点火系统的最佳控制。本文介绍的正是这种技术在480型汽油机上应用的成果。     

普通油环弹力修正系数的计算

0引言 最近,我公司经常接到一些出口国外的普通油环产品,对于这种环的弹力修正系数的确定比较复杂,我们采用了一种近似方法求解,介绍如下,仅供参考.     

带有可调导叶的径流涡轮气动特性的研究

采用数值模拟的方法对单级径向涡轮在导向叶栅的不同开度、不同工况下的全流场进行了三维模拟分析。研究表明,可调导叶对涡轮性能的影响是叶栅收敛度、气流冲角与出气角的综合影响。在综合考虑了导叶损失以及叶轮损失的基础上,提出了变几何径向涡轮随速比变化的调节方案。     

Speed Control System for Brushless Cascade Induction Motors in Control Range of Slips s1>1 and S2>1

This paper describes principles together with analytical and experimental studies of a speed control system for brushless induction motors of cascade connection in the control range of the slips s1> 1 and s2>1 which was devised by one of the authors. Steady state analyses of the performances of the motor control system are discussed, and results of the tests are presented. It is found that the motor can be controlled widely and comparatively efficiently by controlling the converters which are connected electrically to one of the stator windings of the two motors.     

汽轮发电机组轴系扭振主动控制模拟实验研究

在理论分析的基础上建立了国产２００ＭＷ汽轮发电机转子轴系扭振主动控制模拟试验台,并在该试验台上进行了阻尼减振和主动控制减振等多项实验研究,结果表明主动控制可以有铲地抑制汽轮发电机组轴系的扭振。