基于dsPIC30F3011单片机的双路直流稳压电源设计

传统使用的双路直流稳压电源大多是线性电源,缺乏自我保护的功能、故障率较高,且维修工作量很大.本文介绍了一种基于单片机的双路直流稳压电源的设计方法,该设计主电路采用二极管完成AC/DC变换,再通过IGBT进行斩波调节,实现DC/DC变换,输出直流电压.控制电路以dsPIC30F3011为核心,按照时间最优和PID控制方式实现PWM调节.实验证明,该设计电路具有故障自我保护和液晶显示功能,以便准确、快速的对故障进行维修.     

VSC-HVDC高压直流输电实验装置

VSC-HVDC高压直流输电实验装置是由2个独立的电压源型换流器系统组成,每个系统的输出功率器件选用了IGBT模块,体现了该装置的先进技术。IGBT模块采用脉宽调制(PWM)控制方法,该控制方法是本装置的关键技术。文章结合基于VSC的高压直流输电系统的功率传输原理,阐述了PWM的控制方法。     

最大功率点跟踪的太阳能光伏发电系统实验平台设计

设计了太阳能光伏发电铅蓄电池充电的简易实验教学平台,由光伏电池板、充电控制器、阀控式铅蓄电池和变阻箱负载构成。以近似梯度值计算代替一阶求导,提出了一种变步长的电压扰动观察法来实现太阳能光伏发电最大功率点跟踪(MPPT)。以STM8S105单片机为控制器核心,采用Buck直流降压斩波主电路,结合铅蓄电池四阶段充电方式,进行系统硬件和软件设计。测试表明,该实验平台具有MPPT功能,造价较低、结构简单、性能良好、易于操作和维护,能够满足实验教学的要求。     

IGBT电焊机的稳定性设计

介绍了IGBT模块在电焊机中的应用以及IGBT电焊机的众多优点和缺点,指出了IGBT电焊机存在的安全隐患;在此基础上,从电压保护、电流保护、吸收电路以及热保护等方面论述了电源中IGBT模块必要的典型保护方法.     

基于PSpice的IGBT擎住效应的仿真教学分析

绝缘栅双极型晶体管(IGBT)是一种新型的电力电子器件,由于具有良好的特性,在电力电子装置中得到了非常广泛的应用。分析了IGBT的物理结构和工作原理,得出IGBT元胞结构中寄生了一个等效的晶闸管器件,这是引发擎住效应的内部原因。总结了引发擎住效应的外电路条件,即过大的集电极电流或过大的集电极—发射级电压变化率。利用PSpice电路仿真软件建立了一个IGBT擎住效应教学模型电路,并进行具体的分析。     

IGBT在表面处理方面的应用实践

围绕大功率器件IGBT在塑料表面处理方面的实际应用，论述了电路的基本原理、IGBT的器件特性和基本的保护方法．在实际应用中达到令人满意的结果．     

Estimation of the Forces on Rubbing Rotor Bearing System

识别转子轴承系统动态载荷在工程上是十分重要的．本文将离散系统的动态载荷时域识别方法运用到碰摩转子轴承系统中,对转子所受碰摩力进行识别．该法避免了对系统模态参数的求解．仿真结果表明该方法识别精度较好,对于动静摩擦故障,本方法能识别出摩擦点及冲击力的变化情况,从而提高摩擦故障诊断的准确性．     

全桥DC／DC（H桥）变换电路的设计与实现

在对桥式可逆斩波电路作出理论分析的基础上,建立基于MATLAB／Simulnk／PowerSystem工具箱的桥式可逆斩波电路的仿真模型,给出了电阻电感性负载及电动机负载时的仿真结果,并对其进行分析,同时也验证了本文所建模型的正确性．     

Analysis on Dynamic Performance for Active Magnetic Bearing—Rotor System

In the application of active magnetic bearings(AMB),one of the key problems to be solved is the safety and stabiltiy in the sense of rotor dynamics,The project related to the present paper deals with the method for analyzing bearing rotor systems with high rotation speed and specially supported by active magnetic bearings,and studies its rotor dynamics performance,including calculation of the natural frequencies with their distribution characteristics,and the critical speeds of the system.one of the targets of this project is to formulate a theory and method valid for the analysis of the dynamic performance of the active magntic bearing-rotor systemby combining the traditional theory and method of rotor dynamics with the analytical theory and design method based on modern control theory of the AMB system.     

基于PLECS软件的电力电子仿真教学分析

针对电力电子技术课程传统教学过程中强调主电路而忽视控制电路分析的情况,提出在电力电子技术课程教学中引入系统级电力电子仿真软件PLECS进行辅助教学的新方法,通过在降压斩波电路的应用,说明该方法能灵活应用于仿真教学,加深学生对电力电子控制技术知识的理解.     

直流脉宽调速器的功能及应用

系统介绍了一种 X射线管道爬行器电机驱动用软启动直流脉宽调速器 ,包括波形的产生、IGBT的驱动、斩波、器件的保护等电路 ,提出了 IGBT对驱动电路的要求 ,介绍了三菱 IGBT驱动电路 M5 7962 L和逆变电源中 IGBT的过压保护措施     

Rotor broken bar fault diagnosis for induction motors based on double PQ transformation

A new rotor broken bar fault diagnosis method for induction motors based on the double PQ transformation is pre-sented. By distinguishing the different patterns of the PQ components in the PQ plane,the rotor broken bar fault can be detected. The magnitude of power component directly resulted from rotor fault is used as the fault indicator and the distance between the point of no-load condition and the center of the ellipse as its normalization value. Based on these,the fault severity factor which is completely independent of the inertia and load level is defined. Moreover,a method to reliably discriminate between rotor faults and periodic load fluctuation is presented. Experimental results from a 4 kW induction motor demonstrated the validity of the proposed method.     

基于Matlab和PLECS的电力电子仿真实验教学

提出在电力电子技术课程教学中引入Matlab和系统级电力电子仿真软件PLECS进行辅助教学的新方法,结合SEPIC斩波电路,分析了该实验教学的特点和具体思路。基于Matlab和PLECS的辅助实验教学方法能够加深学生对理论知识的理解,克服传统模拟实验教学实验装置数量不足和创新不足的缺点。     

常规FB-ZVS-PWM变换器的改进

本文认真地分析和探讨了常规的全桥移相软开关PWM变换器存在的不足,提出了改进的方法和措施,并在采用IGBT作为开关元件、实现了移相控制的电压软开关桥式逆变电路中得到验证,改进的方法和措施有实际应用意义。     

Investigation of the dynamic characteristics of a dual rotor system and its start-up simulation based on finite element method

Recently, the finite element method (FEM) has been commonly applied in the engineering analysis of rotor dynamics. Gyroscopic moments, rotary inertia, transverse shear deformation and gravity can be included in computational models of rotor-bearing systems. In this paper, a finite element model and its solution method are presented for the calculation of the dynamics of dual rotor systems. A typical structure with two rotor shafts is discussed and the procedure for obtaining the coupling motion equations of the subsystems is illustrated. A computer program is developed to solve critical speeds and to simulate the transient motion. The influence of gyroscopic moments on co-rotation and counter-rotation is analyzed, and the effect of the speed ratio on critical speed is studied. The dynamic characteristics under different conditions of increasing speed during start-up are demonstrated by comparison with transient nodal displacements. The presented model provides a complete foundation for further investigation of the dynamics of dual rotor systems.     

等离子体制备氮化铁磁流体用高频高压脉冲电源的研制

根据等离子体活化装置对电源的要求,利用新型功率器件IGBT设计了一种高频高压大功率脉冲电源,并对IGBT的驱动调制电路、保护电路以及电路频率范围的拓宽和功率提高进行了讨论.结果表明,该电源在功率输出、频率范围、波形等方面均能达到设计要求.     

基于传递矩阵法的涡轮增压器临界转速分析

发动机涡轮增压器是一种轻型高速旋转机械,其作用是通过增压增加气缸进气量,提高发动机的燃油经济性和动力性．发动机涡轮增压器核心部件是双盘双支撑的转子轴承系统,所以对转子轴承系统运动稳定性的研究显得尤为重要．通过传递矩阵法建立求解涡轮增压器转子系统临界转速的计算模型,将某型国产汽油机涡轮增压器转子系统的参数带入数学计算模型．利用Matlab软件编程计算涡轮增压器转子系统的临界转速,并通过台架试验验证了理论计算的正确性,为涡轮增压器转子系统设计提供理论参考．     

感应电机多参数辨识的实验研究

从理论及试验上深入地分析了定子电阻参数变化对定子磁链估计的影响。同时,在伪降阶磁链观测器的基础上提出了定子电阻、转子电阻及转速的参考模型自适应律,从实验结果可以看出电机参数依据本文所得到自适应律进行独立辨识时可以获得的估计精度。     

Nonlinear dynamic analysis of a rotor/bearing/seal system

In this study a new dynamic model of a rotor system is established based on the Hamilton principle and the finite element method (FEM). We analyze the dynamic behavior of the rotor system with the coupled effects of the nonlinear oil film force, the nonlinear seal force, and the mass eccentricity of the disk. The equations of the motion are solved effectively using the fourth order Runge-Kutta method in MATLAB. The dynamic behavior of the system is illustrated by bifurcation diagrams, largest Lyapunov exponents, phase trajectory diagrams, and Poincaré maps. The numerical results show that the rotational speed of the rotor, the pressure drop in the seal, the seal length, the seal clearance, and the mass eccentricity of the disk are the key parameters that significantly affect the dynamic characteristics of the rotor system. The motion of the rotor system exhibits complex types of periodic, quasi-periodic, double-periodic, multi-periodic, and chaotic vibrations. This analysis can be used to guide the design of seal parameters and to diagnose the vibration of rotor/bearing/seal systems.     

一种新的IGBT驱动保护电路

针对IGBT驱动保护问题,提出了一种新的驱动保护电路．采用555集成电路作延时降压电路．电路具有状态检测功能、延时缓降栅压功能和降压功能等功能．此电路的特点是简单,定时精度高,可靠性高,反应快．