Adaptive Gain Tuning Rule for Nonlinear Sliding-mode Speed Control of Encoderless Three-phase Permanent Magnet Assisted Synchronous Motor

In this paper, an adaptive gain tuning rule is designed for the nonlinear sliding mode speed control(NSMSC) in order to enhance the dynamic performance and the robustness of the permanent magnet assisted synchronous reluctance motor(PMa-Syn RM) with considering the parameter uncertainties. A nonlinear sliding surface whose parameters are altering with time is designed at first. The proposed NSMSC can minimize the settling time without any overshoot via utilizing a low damping ratio at starting along with a high damping ratio as the output approaches the target set-point. In addition, it eliminates the problem of the singularity with the upper bound of an uncertain term that is hard to be measured practically as well as ensures a rapid convergence in finite time, through employing a simple adaptation law. Moreover, for enhancing the system efficiency throughout the constant torque region, the control system utilizes the maximum torque per ampere technique. The nonlinear sliding surface stability is assured via employing Lyapunov stability theory. Furthermore, a simple sliding mode estimator is employed for estimating the system uncertainties. The stability analysis and the experimental results indicate the effectiveness along with feasibility of the proposed speed estimation and the NSMSC approach for a 1.1-k W PMa-Syn RM under different speed references, electrical and mechanical parameters disparities, and load disturbance conditions.

Speed Regulation Method Using Genetic Algorithm for Dual Three-phase Permanent Magnet Synchronous Motors

Dual three-phase Permanent Magnet Synchronous Motor(DTP-PMSM)is a nonlinear,strongly coupled,high-order multivariable system.In today’s application scenarios,it is difficult for traditional PI controllers to meet the requirements of fast response,high accuracy and good robustness.In order to improve the performance of DTP-PMSM speed regulation system,a control strategy of PI controller based on genetic algorithm is proposed.Firstly,the basic mathematical model of DTP-PMSM is established,and the PI parameters of DTP-PMSM speed regulation system are optimized by genetic algorithm,and the modeling and simulation experiments of DTP-PMSM control system are carried out by MATLAB/SIMULINK.The simulation results show that,compared with the traditional PI control,the proposed algorithm significantly improves the performance of the control system,and the speed output overshoot of the GA-PI speed control system is smaller.The anti-interference ability is stronger,and the torque and double three-phase current output fluctuations are smaller.

Rotor Strength Analysis of High-speed Permanent Magnet Synchronous Motors

为了对转子进行有效的冷却，在满足电机电磁性能的前提下，可通过减小保护套的厚度来尽可能增大定转子之间的气隙，因而必须对保护套和永磁体进行强度校核。将转子受力状况简化为平面应变问题，在此基础上推导出了两层过盈配合、三层过盈配合转子的应力场、应变场、位移场的解析公式，并利用有限元方法验证了解析公式的正确性。归纳了高速情况下热套式永磁转子强度设计准则，为转子的优化设计提供了理论依据。以一台额定转速120kr／min、10kW的高速永磁同步电机为例，给出了两种常用过盈配合高速电机转子的强度设计方法。

Speed Identification of Speed Sensorless Linear Induction Motor Based on MRAS

In the linear induction motor control system,the optical grating speed transducer is susceptible to strong magnetic field interference.What's more,it may reduce motor integration and raise device costs.Therefore a speed identification method to replace grating speed transducer is studied in this article.This speed identification method for linear induction motor mainly adopts Model Reference Adaptive Method(Abbreviated as MRAS)and Popov Hyperstability Theory.The research content of this paper can be divided into four parts.First,the mathematical model of the motor based on the model reference adaptive system structure is deduced.Second,the adaptive law of the estimated speed is solved by Popov hyper-stability theory,which ensures the stability of the system.Third,the simulation model of the linear induction motor speed identification control system based on model reference adaptation is built in the MATLAB environment.Finally,the simulation test and analysis are carried out.The simulation results show that the speed identification control system can track the actual speed of the linear induction motor well in the no-load operation and the load operation,and the stability of the system is guaranteed in the full speed range.

Research Progress of Key Technology of High-Speed and High Precision Motorized Spindles

High speed machining and high precision machining are two tendencies of themanufacturing technology worldwide. The motorized spindle is the core component of the machine toolsfor achieving the high speed and high precise machining, which affects the general developmentlevel of the machine tools to a great extent. Progress of the key techniques is reviewed in thispaper, in which the high speed and high precision spindle bearings, the dynamical and thermalcharacteristics of spindles, the design technique of the high frequency motors and the drivers, theanti-electromagnetic damage technique of the motors, and the machining and assembling technique areinvolved. Finally, tha development tendencies of the motorized spindles are presented.

Experimental Studies on Support Systems of High Speed Motors With Flexible Squirrel-cage Support and Squeeze Film Dampers

以100kW级工作转速为45000r／min的高速永磁同步电机为实验样机，对采用鼠笼式弹性支撑和挤油膜阻尼器的滚动轴承支撑系统进行研究。分析了弹性支撑和挤压油膜阻尼器的刚度和阻尼特性，在此基础上分别计算出刚性支撑和弹性阻尼支撑时轴承一转子系统的临界转速和瞬态动力特性。最后在样机上进行对比实验，并对电机机壳振动加速度和弹性支撑笼条微应变信号进行分析。结果表明，弹性阻尼支撑可以使转子以较低的转速通过其刚体模态，同时对转子的振动起到良好的抑制作用。实验样机稳定运行在设计工作转速，其分析和实验结果为高速电机轴系设计和动力学分析提供了参考。

MECHANICAL-ELECTRIC COUPLING DYNAMICAL CHARACTERISTICS OF AN ULTRA-HIGH SPEED GRINDING MOTORIZED SPINDLE SYSTEM

On the basis of the traditional mechanical model of a grinding wheel rotor and the mechanical-electric coupling model with ideal sinusoidal supply, taking high-frequency converting current of inverter power switches into further consideration, a modified mechanical-electric coupling model is created. The created model consists of an inverter, a motorized spindle, a grinding wheel and grinding loads. Some typical non-stationary processes of the grinding system with two different supplies, including the starting, the speed rising and the break in grinding loads, are compared by making use of the created model. One supply is an ideal sinusoidal voltage source, the other is an inverter. The theoretical analysis of the high-order harmonic is also compared with the experimental result. The material strategy of suppressing high-order harmonic mechanical-electric coupling vibration by optimizing inverter operating parameters is proposed.

LUBRICATION FILM FORMATION MECHANISM OF SLIPPER PAIRS IN LOW SPEED HIGH TORQUE HYDRAULIC MOTORS

Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connecting rod type low speed high torque （LSHT） hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by computer simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coefficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.

Analysis for Rotor Losses of High Speed Permanent Magnet Synchronous Motor

This paper presents an analysis based on analytical method for solid rotor motors for determining the rotor eddy current losses due to the current harmonics of the stator winding. The accuracy of the analytical results is verified by experiments.

Application of Super-Synchronization Speed Control Technology in Two 80 MVA Motor-Generator Units of HL-2A

Two sets of super-synchronization speed control assemblies for two 80 MVA motor-generator units have been developed successfully in order to satisfy the demand of the toroidal field system in the HL-2A tokamak. Based on the three-phase logical no-circumfluence a.c./a.c. cycloconverter, the speeds of two 2500 kW double fed drive motors have been regulated by means of the vector control technology. The maximum operating speed of each motor- generator unit has been raised from 1488 rpm （revolutions per minute） to 1650 rpm and the released energy of each unit during a pulsed discharge can reach 500 MJ. As a result, the toroidal field system has the capacity to provide 2.8 tesla （T） in HL-2A experiments.

Frequency-Speed Control Model Identification of Ultrasonic Motor Using Step Response

Control model of ultrasonic motor is the foundation for high control performance.The frequency of driving voltage is commonly used as control variable in the speed control system of ultrasonic motor.Speed control model with the input frequency can significantly improve speed control performance.Step response of rotating speed is tested.Then,the transfer function model is identified through characteristic point method.Considering time-varying characteristics of the model parameters,the variables are fitted with frequency and speed as the independent variables,and the variable model of ultrasonic motor system is obtained,with consideration of the nonlinearity of ultrasonic motor system.The proposed model can be used in the design and analysis of the speed control system in ultrasonic motor.

Wide speed range for traction motor in braking force of electric braking control system

A vehicle stopping method using an electric brake until a traction motor is stopped is studied. At the moment of vehicle stop, electric brake is changed to control mode where torque is reduced at a low speed. Gradient is controlled by estimating the load torque of motor, thereby traction motor is not rotated after stop. In addition, coasting operation and brake test are performed from normal-opposite operation and start using a small-scale model comprising the inertial load equipment and the power converter. Further, traction motor is made to be equipped with a suspension torque. Pure electric braking that makes traction motor stop by an air brake at the time of stop is also implemented. Constant torque range and constant power range are expanded during braking so that braking force is secured with the electric brakes even in high speed region. Therefore, vehicle reduction effect can be expected by reducing parts related with an air brake which is not used frequently by using a pure electric brake in the M car in wide speed region. Further, maintenance of brake system can be reduced. Besides, ride comfort of passenger in the electric rail car, energy efficiency improvement, and noise reduction effect can be additionally expected. Further, an improved brake method that uses only an electric brake till motor stop is proposed by comparing those in the blending brake that uses an air brake while reducing brake torque at vehicle stop.

Virtual Speed Sensorless Desired Control Strategy of Maglev Single-sided Linear Induction Motors

单边短初级长次级直线感应电机己普遍应用于低速磁悬浮的驱动系统。由于在动态纵向边端效应影响下等效电路不对称，单边直线感应电机（single-sided linear inductionmotor，SLIM）的一些参数非线性变化。传统的应用于旋转电机的无速度传感器方法不再适用。首先分析了SLIM的M／T轴等效电路，选择次级磁链作为速度观测器状态变量。根据李雅普诺夫系统稳定性判据，推导出适用于SLIM的无速度传感器辨识；然后，采用反馈广义积分观测器控制稳态辨识速度的双幅脉振幅值；引入虚拟期望变量（virtualdesiredvariable，VDV）法，利用估算速度参与SLIM的恒滑差频率矢量控制。仿真与实验对所提控制算法的有效性和实用性进行了验证，所得结论可为磁悬浮的无速度传感器控制提供参考。

Dynamic Model Identification for Ultrasonic Motor Frequency-Speed Control

The mathematical model of ultrasonic motor(USM)is the foundation of the motor high performance control.Considering the motor speed control requirements,the USM control model identification is established with frequency as the independent variable.The frequency-speed control model of USM system is developed,thus laying foundation for the motor high performance control.The least square method and the extended least square method are used to identify the model.By comparing the results of the identification and measurement,and fitting the time-varying parameters of the model,one can show that the model obtained by using the extended least square method is reasonable and possesses high accuracy.Finally,the frequency-speed control model of USM contains the nonlinear information.

Application of Diagonal Recurrent Neural Network toDC Motor Speed Control Systems

A new kind of dynamic neural network--diagonal recurrent neural network (DRNN) and its learning method and architecture are presented. A direct adaptive control scheme is also developed that is applied to a DC (Direct Current) speed control system with the ability to auto-tune PI (Proportion Integral) parameters based on combining DRNN with PI controller. The simulation results of DRNN show better control performances and potential practical use in comparison with PI controller.

A Digital Phase Locked Loop Speed Control of Three Phase Induction Motor Drive: Performances Analysis

This paper deals with performance analysis and implementation of a three phase inverter fed induction motor (IM) drive system. The closed loop control scheme of the drive utilizes the Digital Phase Locked Loop (DPLL). The DPLL is safely implemented all around the well known integrated circuit DPLL 4046. An ex-perimental verification is carried out on one kw scalar controlled IM system drives for a wide range of speeds and loads appliance. This presents a simple and high performance solution for industrial applications.

CFD Study of Forced Air Cooling and Windage Losses in a High Speed Electric Motor

High speed and high efficiency synchronized electric motors are favored in the automotive industry and turbo machinery industry worldwide because of the demands placed on efficiency. Herein an electric motor thermal control system using cooling air which enters from the drive end of the motor and exits from the non-drive end of the motor as the rotor experiences dissipates heat is addressed using CFD. Analyses using CFD can help to find the appropriate mass flow rate and windage losses while satisfying temperature requirements on the motor. Here, the air flow through a small annular gap is fed at 620 L/min (0.011 kg/sec) as the rotor spins at 100,000 rpm (10,472 rad/sec) and the rotor dissipates 200 W. The CFD results are compared with experimental results. Based upon the CFD findings, a novel heat transfer correlation suitable for large axial Reynolds number, large Taylor number, small annular gap Taylor-Couette flows subject to axial cross-flow is proposed herein.

DC Motor Speed Regulator via Active Damping Injection and Angular Acceleration Estimation Techniques

This paper suggests a novel model-based nonlinear DC motor speed regulator without the use of a current sensor.The current dynamics,machine parameters and mismatched load variations are considered.The proposed controller is designed to include an active damping term that regulates the motor speed in accordance with the first-order low-pass filter dynamics through the pole-zero cancellation.Meanwhile,the angular acceleration and its reference are obtained from simple first-order estimators using only the speed information.The effectiveness is experimentally verified using hardware comprising the QUBEServo2,myRIO-1900,and LabVIEW.