Design and Test of Motor Double Fed Speed Regulating System for Conveyer Belt

This paper introduces the design of doubly fed system for conveyor belt motor, the system adopts stator flux orientation vector control technology and AC-AC inverter motor speed and power factor control, and carried on the test in transmission field. This paper introduces in detail the structure and characteristic of DSP system, and gives a design scheme of Doubly Fed Speed Control System of motor based on this chip.

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.

Simulation Analysis and Verifcation of Temperature and Stress of Wheel-Mounted Brake Disc of a High-Speed Train

During the braking process,a large amount of heat energy is generated at the friction surfaces between the brake disc and pads and rapidly dissipates into the disc volume.In this paper,a three-dimensional thermo-mechanical coupling model of high-speed wheel-mounted brake discs containing bolted joints and contact relationships is established.The direct coupling method is used to analyze the temperature and stress of the brake discs during an emergency braking event with an initial speed of 300 km/h.A full-scale bench test is also conducted to monitor the temperatures of the friction ring and bolted joints.The simulation result shows that the surface temperature of the friction ring reaches its peak value of 414°C after 102 s of braking,which agrees well with the bench test result.The maximum alternating thermal stress occurs in the bolt hole where the maximum circumferential compressive stress is−658 MPa and the maximum circumferential tensile stress is 134 MPa.During the braking process,the out-of-plane deformation of the middle part of the friction ring is larger than that of the edge,which increases the axial tensile load of the connecting bolt.This work provides support for the design of brake discs and connecting bolts.

Analysis of torque transmitting behavior and wheel slip prevention control during regenerative braking for high speed EMU trains

The wheel-rail adhesion control for regenerative braking systems of high speed electric multiple unit trains is crucial to maintaining the stability,improving the adhesion utilization,and achieving deep energy recovery.There remain technical challenges mainly because of the nonlinear,uncertain,and varying features of wheel-rail contact conditions.This research analyzes the torque transmitting behavior during regenerative braking,and proposes a novel methodology to detect the wheel-rail adhesion stability.Then,applications to the wheel slip prevention during braking are investigated,and the optimal slip ratio control scheme is proposed,which is based on a novel optimal reference generation of the slip ratio and a robust sliding mode control.The proposed methodology achieves the optimal braking performancewithoutthewheel-railcontactinformation.Numerical simulation results for uncertain slippery rails verify the effectiveness of the proposed methodology.

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.

Position Control Optimization of Aerodynamic Brake Device for High-speed Trains

The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions--constant, linear, and quadratic--are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25,71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

Using Artificial Neural Networks for Energy Regulation Based Variable-speed Electrohydraulic Drive

In the energy regulation based varibable-speed electrohydraulic drive system, the supply energy and the demanded energy, which will affect the control performance greatly, are crucial. However, they are hard to be obtained via conventional methods for some reasons. This paper tries to a new route： the definitive numerical values of the supply energy and the demanded energy are not required, except for their relationship which is called energy state. A three-layer back propagation（BP） neural network was built up to act as an energy analysis unit to deduce the energy state. The neural network has three inputs： the reference displacement, the actual displacement of cylinder rod and the system flowrate supply. The output of the neural network is energy state. A Chebyshev type II filter was designed to calculate the cylinder speed for the estimation of system flowrate supply. The training and testing samples of neural network were collected by the system accurate simulation model. After off-line training, the neural network was tested by the testing data. And the testing result demonstrates that the designed neural network was successful. Then, the neural network acts as the energy analysis unit in real-time experiments of cylinder position control, where it works efficiently under square-wave and sine-wave reference displacement. The experimental results validate its feasibility and adaptability. Only a position sensor and some pressure sensors, which are cheap and have quick dynamic response, are necessary for the system control. And the neural network plays the role of identifying the energy state.

Demonstration of a Dynamic Braking System for Reduced Runaway Speed of Hydraulic Turbines

Reducing the overspeed during load rejection would benefit the mechanical and hydraulic systems in a hydropower station. This paper presents some selected results of a pilot installation of a dynamic braking system. The 4 MW dump load was installed and tested on a 10 MW Francis turbine unit. The results show that the overspeed reduction is obtained and compares well with simulation results. Further, a reduction in vibration levels is positive as well as the reduced time for stopping and possible resynchronization. It is argued that a similar system with continuous cooling could be used as an attractive alternative to spillway capacity.

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.

The research of power saving frequency conversion speed regulation experiment system

A power saving frequency difference controlling method was introduced by the double inverter and motor experiment system.The characters of the system under differ- ent loads were investigated.The theoretical analysis and experiment results show the frequency difference method is a ideal power saving speed regulation method for the dou- ble inverter and motor system.The experiment system is simply structured,convenient to operate and provides a new way of character testing for frequency conversion speed regulation.

A Model-Based Unmatched Disturbance Rejection Control Approach for Speed Regulation of a Converter-Driven DC Motor Using Output-Feedback

The speed regulation problem with only speed measurement is investigated in this paper for a permanent magnet direct current(DC)motor driven by a buck converter.By lumping all unknown matched/unmatched disturbances and uncertainties together,the traditional active disturbance rejection control(ADRC)approach provides an intuitive solution for the problem under consideration.However,for such a higher-order disturbed system,the increase of poles for the extended state observer(ESO)therein will lead to drastically growth of observer gains,which causes severe noise amplification.This paper aims to propose a new model-based disturbance rejection controller for the converter-driven DC motor system using output-feedback.Instead of estimating lumped disturbances directly,a new observer is constructed to estimate the desired steady state of control signal as well as errors between the real states and their desired steady-state responses.Thereafter,a controller with only speed measurement is proposed by utilizing the estimates.The performance of the proposed method is tested through experiments on dSPACE.It is further shown via numerical calculations and experimental results that the poles of the observer within the proposed control approach can be largely increased without significantly increasing magnitude of the observer gains.

Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min, the coefficient of friction decreased rapidly. When the brake speed is 3000r/min, the material’s wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to abradant and oxidation wear.

The Applications of High-voltage variable frequency speed regulation System in Main Exhauster of Sintering

Main Exhauster is one of the main equipment of sintering production. It needs to consume a lot of electricity. Therefore, the system＇ s reconstruction for energy-saving will effectively reduce electricity for the production. The paper takes an iron and steel enterprise that had successfully transformed the synchronous motors of main exhauster of sintering as an example, which describes the application of high-voltage variable frequency speed regulation system in main exhauster of Sintering, so as to provide a reference for other iron and steel enterprises.

基于负载特性测试的矢量控制交流变频调速系统研究

针对堆垛机起升机构使用的三相异步电动机调速精度低、动态响应速度慢的问题,文中提出使用转子磁场定向矢量控制方法进行三相异步电动机调速。首先,根据交流变频调速系统的原理进行参数的等效坐标变换,将交流电动机的定子电流分解成转矩电流和励磁电流分量用于控制电动机的电磁转矩和励磁磁场,并结合三相异步电动机的特性曲线和变频器的工作原理在LabVIEW中建立数学模型;然后,利用Simulink平台对堆垛机起升机构的控制系统进行仿真。对比仿真与实测结果表明,转子磁场定向矢量控制的变频调速方法的使用提高了堆垛机起升机构在实际应用中的转矩和转速精度。

永磁同步电机自整定分数阶PID速度控制

为优化永磁同步电机(PMSM)控制效果,提高电机整体控制性能及鲁棒性,提出自整定分数阶PID控制策略,并应用于永磁同步电机速度环控制。该控制器较常规PID多了2个可调参数,能够更加灵活地控制受控对象。设计了前馈解耦的电流控制器、模糊分数阶PID控制器,利用模糊规则在线整定控制器参数;在Matlab中搭建永磁同步电机仿真模型,对比本文控制策略与常规PID控制、普通分数阶PID控制及滑模控制,分析不同速度下PMSM变负载系统转速仿真曲线。仿真结果表明,模糊分数阶PID控制器抗干扰性强、跟踪精度高、响应速度快,具有更好的控制效果。

基于剩余碰撞时间的线控制动分层控制策略

针对不同制动工况需求的制动策略存在差异的情况,提出一种线控制动分层控制策略.在该分层策略的上层,利用二阶TTC安全碰撞时间模型计算出车辆与前车的剩余碰撞时间,以此作为依据进行制动策略的选取,并建立了汽车二自由度模型、车身法向受力模型和Burckhardt轮胎模型;在该分层策略的下层,进行了制动力在轮间的分配,使用序列二次规划(SQP)方法,分别在一般制动、紧急制动、失稳制动3种工况下,以轮胎滑移率为对象建立优化函数,对车辆制动力进行了优化分配.使用MATLAB/Simulink和Carsim进行了联合仿真,对所提出3种工况下的制动分配策略进行了有效性验证.结果表明:在一般制动工况下,采用该策略时相比对照工况制动距离减少18.08%,制动时间减少25.12%;在紧急制动工况下,采用该策略时相比对照工况制动距离减少19.17%,制动时间减少12.79%;在失稳制动工况下,该策略可通过轮胎差扭来提升车辆的横向稳定性.采用文中制动策略显著提升了车辆的制动效能.

交流调速系统模糊分数阶内模PID控制方法

针对高精度交流调速系统,将分数阶微积分理论、内模控制、模糊控制和比例积分微分(proportional integral differential,PID)控制相结合,提出了一种模糊分数阶内模PI-νDa+ν控制器。首先,考虑到分数阶微积分的优良特性,将其引入交流调速系统的内模PID控制器中,得到了一种分数阶内模PI-νDa+ν控制器,该控制器包含3个可调参数。然后,通过阶跃响应分析了控制器参数对系统性能的影响,并根据分析结果设计了模糊控制器,实现了控制器参数的智能整定,克服了分数阶控制器参数整定困难的不足。实验结果表明,模糊分数阶内模PI-νDa+ν控制器可以使系统具有良好的动态响应、扰动抑制特性和克服参数摄动的鲁棒性。

计及转速及功率限制的双馈抽蓄自适应调频控制

双馈抽水蓄能机组可以通过变速运行灵活调节功率,在发电和抽水工况下均具备一定的调频潜能.为挖掘双馈抽水蓄能机组在不同工况下的调频能力,分别建立其适应不同工况运行特点的调频控制模块,提出计及转速及功率限制的自适应变参数调频策略.首先,在建立考虑可逆式水泵水轮机动态特性的机组模型基础上,构建发电工况下将频率偏差转换为附加功率指令、抽水工况下将频率偏差转换为附加转速指令的调频模块.其次,分析各调频参数对于频率动态响应的影响,并以系统频率偏差最小为目标,以机组的转速及功率限制为约束,提出基于改进粒子群算法的多工况最优调频参数确定方法,在此基础上形成随机组状态实时调整的自适应变参数调频策略.最后,以含双馈抽水蓄能机组的四机两区系统为例进行仿真分析,仿真结果表明:所提调频策略使机组在不同工况、不同运行状态下均具有良好的调频性能.

基于STM32F的智能风扇调速系统设计与研究

随着人们环保意识增强和社会对绿色生活的倡导,节能减排成为了家电产品设计的重要考虑因素。基于STM32F设计了智能风扇调速系统,通过精准调速控制和智能化管理,实现对风扇转速的智能、高效调控,可以有效降低能耗,为新一代的智能家居系统提供有益的技术支持和创新思路。

阀控式铅酸电池结构与包装精益设计

为了优化新能源动力阀控式铅酸蓄电池包装工艺,采用优化电池结构设计的方案,设计出嵌槽倒角式电池盖。将配套的提手绳由嵌槽嵌入圆孔,提高了安装速度。电池装箱后,将配套的提手管置于电池盖的顶面与正面倒角A处,将配套的螺栓置于电池盖的侧面与正面倒角B处,省去泡沫垫板。纸箱封合后外观平整。用嵌槽倒角式电池盖组装的阀控式铅酸蓄电池与传统的阀控式铅酸蓄电池相比,不仅提高提手绳安装速度约1倍,又将提手绳、泡沫垫板和纸箱三者的成本节约367.65~424.05万元/a。