Recent Developments of Modulation and Control for High-Power Current-Source-Converters Fed Electric Machine Systems

The pulse-width-modulated(PWM)current-source converters(CSCs)fed electric machine systems can be considered as a type of high reliability energy conversion systems,since they work with the long-life DC-link inductor and offer high fault-tolerant capability for short-circuit faults.Besides,they provide motor friendly waveforms and four-quadrant operation ability.Therefore,they are suitable for high-power applications of fans,pumps,compressors and wind power generation.The purpose of this paper is to comprehensively review recent developments of key technologies on modulation and control of high-power(HP)PWM-CSC fed electric machines systems,including reduction of low-order current harmonics,suppression of inductor–capacitor(LC)resonance,mitigation of common-mode voltage(CMV)and control of modular PWM-CSC fed systems.In particular,recent work on the overlapping effects during commutation,LC resonance suppression under fault-tolerant operation and collaboration of modular PMW-CSCs are described.Both theoretical analysis and some results in simulations and experiments are presented.Finally,a brief discussion regarding the future trend of the HP CSC fed electric machines systems is presented.

Global Control Simulation of Electric Vehicle Based on Finite State Machine Theory

Finite state machine theory (FSM) is introduced and applied to global control of electric vehicle. Theoretical adaptation for application of FSM in control of electric vehicle is analyzed. Global control logic for parts of electric vehicle is analyzed and built based on FSM. Using Matlab/Simulink, BJD6100-HEV global control algorithm is modeled and prove validity by simulation.

Machine Learning-based Electric Load Forecasting for Peak Demand Control in Smart Grid

Increasing energy demands due to factors such as population,globalization,and industrialization has led to increased challenges for existing energy infrastructure.Efficient ways of energy generation and energy consumption like smart grids and smart homes are implemented to face these challenges with reliable,cheap,and easily available sources of energy.Grid integration of renewable energy and other clean distributed generation is increasing continuously to reduce carbon and other air pollutants emissions.But the integration of distributed energy sources and increase in electric demand enhance instability in the grid.Short-term electrical load forecasting reduces the grid fluctuation and enhances the robustness and power quality of the grid.Electrical load forecasting in advance on the basic historical data modelling plays a crucial role in peak electrical demand control,reinforcement of the grid demand,and generation balancing with cost reduction.But accurate forecasting of electrical data is a very challenging task due to the nonstationary and nonlinearly nature of the data.Machine learning and artificial intelligence have recognized more accurate and reliable load forecastingmethods based on historical load data.The purpose of this study is to model the electrical load of Jajpur,Orissa Grid for forecasting of load using regression type machine learning algorithms Gaussian process regression(GPR).The historical electrical data and whether data of Jajpur is taken for modelling and simulation and the data is decided in such a way that the model will be considered to learn the connection among past,current,and future dependent variables,factors,and the relationship among data.Based on this modelling of data the network will be able to forecast the peak load of the electric grid one day ahead.The study is very helpful in grid stability and peak load control management.

Eco-Friendly Selection of Diesel Generator Based on Genset-Synchro Technology for Off-Grid Remote Area Application in the North of Quebec

For most of their energy requirements, greater part of remote communities and small islands around the world rely on imported fossil fuels. The economical cost of energy is therefore very high not only due to inherent cost of fuel, but also due to transportation and due to maintenance costs. One solution for saving fuel in a diesel generator is to allow the engine to operate directly in relation to the request for electrical load at variable speeds. Genset-Synchro Technology has developed an innovative variable speed?generator technology (patent pending) that allows applications where power demand varies widely to benefit from the new technology that maintains constant voltage and frequency while adjusting the generator stator speed to power demand. This paper will present an innovative approach for optimizing the energy production based from the fact that the structure that contains the stator windings of the generator is mounted on roller bearings, which allows its free rotation around the axis of the rotor, consequently stopping the stator structure from being static and aims to minimize the unit cost of electricity. Case study on application in remote area in the north of Quebec is described. A saving of 7%?-?9% on fuel consumption and greenhouse gas (GHG) under low winter ambient temperatures has been registered.

Application of direct torque control to electric screw presses for speeding up torque response and reducing starting current

Fast response and stable torque output are crucial to the performance of electric screw presses. This paper describes the design of a direct torque control (DTC) system for speeding up torque response and reducing the starting current of electric screw presses and its application to the J58K series of numerical control electric screw presses with a dual-motor drive. The DTC drive system encompasses speed control, torque reference control, and switching frequency control. Comparison of the DTC dual-AC induction motor drive with corresponding AC servo motor drive showed that for the J58K-315 electric screw press, the DTC drive system attains a higher maximum speed (786 r/min) within a shorter time (1.13 s) during a 250 mm stroke and undergoes smaller rise in temperature (42.0 °C) in the motor after running for 2 h at a 12 min-1 strike frequency than the AC servo motor drive does (751 r/min within 1.19 s, and 50.6 °C rise). Moreover, the DTC AC induction motor drive, with no need for a tachometer or position encoder to feed back the speed or position of the motor shaft, enjoys increased reliability in a strong-shock work environment.

Reliability Analysis of Electrical System of Computer Numerical Control Machine Tool Based on Bayesian Networks

The core of computer numerical control(CNC) machine tool is the electrical system which controls and coordinates every part of CNC machine tool to complete processing tasks, so it is of great significance to strengthen the reliability of the electrical system. However, the electrical system is very complex due to many uncertain factors and dynamic stochastic characteristics when failure occurs. Therefore, the traditional fault tree analysis(FTA) method is not applicable. Bayesian network(BN) not only has a unique advantage to analyze nodes with multiply states in reliability analysis for complex systems, but also can solve the state explosion problem properly caused by Markov model when dealing with dynamic fault tree(DFT). In addition, the forward causal reasoning of BN can get the conditional probability distribution of the system under considering the uncertainty;the backward diagnosis reasoning of BN can recognize the weak links in system, so it is valuable for improving the system reliability.

基于PLC的数控机床电气设备电压稳态控制研究

数控机床电气设备的电压稳态控制的网络损耗高,导致控制效果差,提出基于PLC的数控机床电气设备电压稳态控制研究。根据电气设备等效电路,分析数控机床电气设备无功输出原理,通过压降计算原理,计算数控机床电气设备间的压降,设计电气设备电压稳态控制方案,实现数控机床电气设备的电压稳态PLC控制。实验结果表明,设计方法将数控机床电气设备网络损耗控制在25 W以内,从而保证数控机床电气设备的安全稳定运行,该方法具备可行性和有效性。

数控机床电气控制部分的维护和保养研究

数控设备是一种集机械、电气、液压、气动和数控系统为一体的高科技产品。数控机床维护和保养水平的高低,直接决定了一台数控机床运行的可靠性程度和故障率。本文就数控机床电气控制部分的维护和保养进行了系统阐述,针对数控机床电气控制部分如何更高效且方便地维护及查找故障,进行了开发性的研究,提出了一种高效查找强电故障的方法;为能实现更高层次的智能诊断建立了硬件基础。

基于案例驱动的“机床电气控制与PLC”教学探索与实践

“机床电气控制与PLC”是机械工程专业课程,随着工业机器人的发展,PLC技术在工业控制系统中发挥着越来越重要的作用,现阶段已经发展成为自动化行业的主流技术之一。本文结合我校应用型大学的办学理念,侧重于学生的实践能力培养,教学过程中以实际工程案例为驱动,将理论应用于实践中,在知识传授的同时,将德育元素融入教学内容,通过课程知识与工程实践联系,推进全员、全过程、全方位育人。

The Electrical Control System PLC Transformation of The XA6132 Milling

For the electrical control system of XA6132 milling machine circuit complexity, reliability and flexibility, high failure rate. Mitsubishi FX2N-40MR programmable controller is used to improve the performance and efficiency of the entire electrical control system by technological transformation. Mitsubishi FX2N-d0MRPLC on electrical control system transformation can expand link to the technological transformation of the similar equipments.

The Electrical Control System PLC Transformation of The T68 Boring

T68 boring machine electric control system circuit is complex, its reliability and flexibility is poor with high failure rate. The mitsubishi FX2N-40MR Programmable controller for the technical innovation of electric control system improves the work performance of the whole electric control system and the work efficiency. This paper introduces the mitsubishi FX2N-40MR PLC in T68 boring machine electric control system, the application of the elaborated system＇s hardware and PLC program design can provide work for technical reform of similar equipment.

双馈虚拟同步机快速励磁控制和功角补偿策略

针对以激磁电势为目标控制电压的双馈虚拟同步发电机策略下运行功角大而带来的功率耦合问题,提出采用快速励磁控制消除功角扰动对无功控制的影响,采用功角补偿消除激磁电势扰动对功角有功控制的影响的功率解耦方案。在分析双馈电机数学模型及双馈虚拟同步机整体控制策略的基础上,构建计及无功控制环节的双馈虚拟同步机小信号模型。通过分析无功环节PI控制器参数对功角稳定性的影响,设计快速励磁控制策略。通过分析无功扰动与功角变化的关系,确定功角补偿传递函数。设定风速扰动、电网频率扰动和电网电压扰动3种不同工况进行验证。结果表明:所提控制策略可有效避免双馈虚拟同步机大功角运行时有功功率控制和无功功率控制间的相互影响,实现功率解耦。

木材深孔钻床的开发与机电设计

为了解决传统数控系统和机床结构无法直接用于木材深孔加工的问题,研究深孔加工的原理,分析重难点问题,从特殊的工装夹具系统和机床主体结构设计、机床的柔性辅助装夹系统设计、整个机床的电气控制系统和PLC内部的进给插补逻辑算法等进行研究和阐述。使用木材深孔钻床预加工16 mm的孔,测得精度为15.99 mm,完全符合加工要求。木材深孔钻床的设计与研究解决了木材在自动化深孔加工的问题,为该行业提供了解决方案。

电火花加工用磁悬浮驱动器控制系统

针对传统电火花加工时,主轴不能及时调整极间间隙导致加工效率低下的问题,提出了一种多自由度磁悬浮驱动器代替传统电火花主轴运动。分析了该磁悬浮驱动器的结构及原理并建立了磁悬浮驱动器的动力学模型,运用有限元仿真软件对该驱动器所产生的电磁力进行仿真分析,通过设计传统PID控制系统及模糊PID控制系统对磁悬浮驱动器的控制效果进行仿真与实验验证。结果表明,该磁悬浮驱动器具有较好的跟随特性和快速的响应速度及符合要求的电磁力,满足微细电火花加工要求。

基于BECKHOFF IPC的GD包装机组控制系统设计

利用BECKHOFF IPC(工业控制计算机)的控制技术,根据GD包装机工艺特点,设计创新GD包装机IPC控制系统。IPC控制技术目前已经在M5,M8,FOCKE等机型上得到了广泛的应用,烟草机械集团技术中心和国内的几个主要卷烟设备生产厂家也已经准备大力发展这种控制技术。

桌面式电火花加工机床数控系统硬件设计

针对桌面式电火花加工机床数控系统的兼容性和加工放电要求,课题组设计了一款基于ARM和现场可编辑门阵列(field programmable gate array, FPGA)的电火花加工机床数控系统硬件平台。该平台任务分配均匀合理,以ARM处理器为核心搭建上位机,移植Linux系统进行多任务处理、人机界面、插补运算等任务;以FPGA为核心搭建的下位机系统负责运动控制、放电脉冲控制、辅助模块控制等任务;硬件平台的搭建采用了核心板+基板的方式并采用以太网口进行通信。试验结果表明该硬件平台搭建的数控系统可以较好地完成电火花小孔加工。该研究提供了一种移植性好、迭代升级成本低、适配多种脉冲电源的电火花加工机床数控系统硬件平台设计方案。

基于PLC技术的机床电气控制系统优化研究

PLC全称为可编程逻辑控制器(Programmable Logic Controller),是一种专门用于控制工作自动化系统的电子设备。随着工业自动化的发展,PLC以其高度的灵活性和可靠性,成为机床电气控制系统的核心技术。它能实现对机床电气控制系统的优化,提升机床运行稳定性与响应速度,减少维护成本,同时增加系统的可编程性,使其能更好地适应多样化和个性化的生产需求。因此,基于PLC技术的机床电气控制系统优化不仅能够推动制造业的技术进步,还能为企业创造更大的经济效益。

矫直机配套电气系统的研究分析

为进一步提升矫直机对钢铁板材的矫直效率和矫直质量,在对矫直机基本结构和原理概述的基础上,对矫直机电气系统的控制器、变频器进行选型并完成相关接线线路的设计;并重点针对矫直机压入系统完成了位移检测传感器、压入控制方式、控制器和软件流程的设计,为后续矫直机电气控制系统的自动化改造奠定了基础。

基于两级均衡电路的电池组智能均衡方法

为解决传统均衡电拓扑均衡效率较低的问题,文中提出了一种两级均衡拓扑结构。该均衡拓扑将电池组分为组内与组间两种形式,组内采用Buck-Boost均衡电路,组间采用可重构均衡电路,组内与组间可同时均衡,提高了均衡效率。以SOC(State of Charge)作为均衡变量,组内均衡算法采用基于SOC的模糊逻辑控制策略,减少均衡时间,提高均衡效率。使用MATLAB/Simulink软件对电路拓扑建模仿真,并与传统Buck-Boost电路进行对比。仿真结果表明,在充放电状态下,相较于传统Buck-Boost电路,所提算法及均衡拓扑使均衡时间减少了约28%,表明该均衡电路及算法具有良好的性能。