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.

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.

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.

Current Search: Performance Evaluation and Application to DC Motor Speed Control System Design

This paper proposes the current search (CS) metaheuristics conceptualized from the electric current flowing through electric networks for optimization problems with continuous design variables. The CS algorithm possesses two powerful strategies, exploration and exploitation, for searching the global optimum. Based on the stochastic process, the derivatives of the objective function is unnecessary for the proposed CS. To evaluate its performance, the CS is tested against several unconstrained optimization problems. The results obtained are compared to those obtained by the popular search techniques, i.e., the genetic algorithm (GA), the particle swarm optimization (PSO), and the adaptive tabu search (ATS). As results, the CS outperforms other algorithms and provides superior results. The CS is also applied to a constrained design of the optimum PID controller for the dc motor speed control system. From experimental results, the CS has been successfully applied to the speed control of the dc motor.

Dynamo Speed Control and Tectonics—Modeling Earth as a Shunt Wound DC Machine

The Sun’s slow periodic flux transfer to the Earth, the low frequency of Schumann Resonance, and the fixed DC voltage of the capacitor direct us toward direct current (DC) machines for electrical modeling purposes. The Earth exhibits dual characteristics of a motor generator set by motoring the mechanical Earth around its axis, while at the same time generating energy for its spherical capacitor. It follows that electrical and mechanical output of the Earth are powered by the magnitude of the flux transfer events, the constant DC voltage supply and any potential nuclear contribution within the core. Like an induction furnace, powerful magnetic flux from the Sun partially melts the outer iron core of the Earth and magnetizes the inner solid iron core. The solid inner magnetic core acts as a rotating armature similar to a DC machine. All electrical machines experience no load and full load power loss while in operation. Speed control of large rotating DC machines is well understood and has been applied in industry for over a century. Speed can be changed either by varying the field resistance and/or the armature resistance. The characteristic of a constant speed DC machine is such that a change in field resistance will cause a compensatory change in armature resistance to maintain velocity. In the case of the earth, a decrease in armature resistance results in an increase in volume of the iron core, which may result in greater seismic and volcanic activity. Climate change may be the direct result of changes in soil and sea water resistance, which we lump together as field resistance.

基于变结构的协同控制方法及其在DC/DC开关变换器中应用

为解决滑模控制因开关频率不固定而不能实用的问题,引入协同控制方法并将其应用于DC/DC开关变换器。简要介绍协同控制方法的解析生成过程。利用变结构理论分析协同控制方法的收敛速度以及对外部干扰和内部参数变化的鲁棒性。分析表明,协同控制方法开关频率恒定、容易数字实现和离开流形的动态特性较好;从任意初始状态都能按指数收敛到流形;对满足一定匹配条件的系统内部参数扰动和外部干扰具有不变性。以带恒功率负载的Boost变换器为例,讨论了协同控制器的设计问题,给出该闭环系统的稳定条件,基于稳定条件设置协同控制参数。Simulink仿真结果表明,协同控制器能渐近稳定在目标工作点上,对负载突变和负载功率突变具有较强的鲁棒性。

多相交错并联磁集成双向DC/DC变换器中耦合电感的通用设计准则

针对多相交错并联双向DC/DC变换器中的耦合电感器设计困难这一问题,提出具有普遍适用性的耦合电感器通用设计准则。以电感全部对称型耦合电感器的Buck+Boost型交错并联磁集成双向DC/DC变换器为例,研究变换器的Buck模态转换规律,得到变换器的等效稳态电感和等效暂态电感表达式,推导出变换器的稳态电流纹波和暂态电流响应速度与占空比、相数及电感耦合系数之间的关系。总结出交错并联双向DC/DC变换器中耦合电感的通用设计准则,按照这一准则,在给定占空比时,通过合理选择耦合电感器的耦合系数,可以既减小稳态相电流纹波又提高暂态输出电流响应速度。最后,通过实验验证了通用设计准则的正确性。

基于磁链函数的BLDC无速度传感器控制策略

针对高速无刷直流电机的驱动控制问题,基于与转速无关的磁链方程,设计了一种无刷直流电机无速度传感器高速驱动控制方案。首先,基于无刷直流电机的电路模型,推导了适用于电机低速运行且与转速无关的磁链方程,保证了电机低速时的可靠运行;然后,设计了电机高速运行时的校正策略,以提供高速时准确的换相点,进而形成了全转速范围内适用的无速度传感器闭环控制系统。最后,基于高速无刷直流电机驱动试验平台开展了全转速范围内的电机驱动控制试验,试验结果验证了所设计控制方案的有效性。

基于锁相环倍频的BLDCM速度控制系统设计

介绍一种基于锁相环六倍频速度采集的无刷直流电机(BLDCM)控制系统,以高性能处理器STM32为核心控制元件,采用锁相环倍频技术实现对电机转速的高精度控制。该系统包括处理器、驱动电路、逆变电路、倍频电路和电机,其中倍频电路对三路霍尔信号实现六倍频处理,输出作为系统的速度反馈。经仿真和实际测试,所设计的锁相环六倍频电路,能够准确有效地进行速度采集和处理,从而提高控制系统速度采集的精度。实验表明:该控制系统实用性强,具有较高的工程应用价值。

DCM模式下双向DC/DC变换器的性能分析

针对目前交错并联磁集成双向DC/DC变换器工作在DCM模态下的分析不全面这一研究现状,以三相电感进行耦合的三相交错并联磁集成Buck/Boost双向DC/DC变换器为实例,在轻载时关断MOS管,利用MOS管的体二极管具有单向导电的特性,避免电感电流出现负值,从而降低变换器的能量损耗,提高变换器的效率。首先,深入分析了运行在Buck状态下的双向DC/DC变换器的DCM模态的稳态性能;其次,分析了变换器的工作状态转换条件,求出各模态转换的临界负载电流,并且通过引入的变比与其他参数之间的关系来具体分析变换器在各种工作情况(CCM/DCM)下的每一相相电流的变化规律;最后,通过仿真和试验的实际数据来验证理论分析的正确性。

电力机车DC600V供电系统的改进

为适应“4·18”提速需要,对电力机车DC600V供电系统进行冗余改造,加装车载故障诊断和远程监控系统。新装置统一了列车供电接地方式,提高了可靠性,实现了信息化,改善了维修性能,现场应用证明效果良好。

交错并联双向DC/DC变换器Buck模式下的耦合电感设计规则

针对目前交错并联双向DC/DC变换器中耦合电感设计规范不全面这一问题,以三相交错并联双向DC/DC变换器为例,在Buck模式下占空比在1/3～2/3范围内,研究变换器采用分立电感和耦合电感,对稳态电流纹波及暂态电流的响应速度的影响。通过对比,证明采用耦合电感具有减小稳态相电流纹波或者增大暂态总输出电流响应速度的作用,且占空比越接近1/3和2/3,耦合越强,效果越明显。给出一个耦合电感的设计规则,在这一规则下选择电感的耦合系数,既能减小变换器的稳态相电流纹波,又能提高暂态总输出电流响应速度。最后,通过实验证明了耦合电感具有提高暂态总输出电流响应速度和减小稳态相电流纹波的作用,从而证明了设计规范的正确性。

用于高速ADC的低抖动时钟稳定电路

介绍了一种用于高速ADC的低抖动时钟稳定电路。这个电路由延迟锁相环(DLL)来实现。这个DLL有两个功能:一是通过把一个时钟沿固定精确延迟半个周期,再与另一个沿组成一个新的时钟来调节时钟占空比到50%左右;二是调节时钟抖动。该电路采用0.35μm CMOS工艺,在Cadence Spectre环境下进行仿真验证,对一个8 bit、250 Msps采样率的ADC,常温下得到的时钟抖动小于0.25 ps rms(典型的均方根)。

纺织印染机械多电机群变频调速同步DCS

针对纺织、印染机械传统多电机拖动同步控制系统操作管理和使用维护都不方便以及故障率高,维修工作量大,严重影响生产的问题,论述了变频器永磁同步电机群调法、变频器电流负反馈软机械特性法和大小电机变频调速法3种变频调速同步原理和方法,研究了采用计算机通过RS-485控制总线控制变频器实现的多电机群变频调速同步新方案,为其设计了基于MCGS的集散控制系统(DCS)。该方案极大地简化了同步拖动控制系统结构,降低了设备成本,大大提高了系统的可靠性和控制管理水平。

VSC-HVDC系统风力发电结构分析与控制

针对基于电压源换流器的高压直流输电(voltage source converter based high voltage direct current,VSC-HVDC),提出了基于永磁同步风力发电机、不控整流和Boost电路的变速直流风力发电系统结构。首先给出先并后串的新型风电场结构;然后建立最小串联系统的简化模型,用一种基于直流电压电流乘积控制的最大风能跟踪控制算法解析出输出电压和输出功率的关系。仿真结果表明:最小串联系统中的2个机组可以互不影响地独立运行,输出电压按照输出功率的变化而变化,同时2个机组均具有较好的最大风能跟踪精度和速度。

基于带抽头电感准Z源变换器的BLDCM控制系统研究

基于带抽头电感的准Z源网络,构建一种永磁无刷直流电机(BLDCM)的控制系统。利用该准Z源网络的高电压增益特性,实现两种工作模式的平滑切换,有效拓宽了无刷直流电机控制系统的调速范围,并弥补了电源端故障时电机转速和转矩特性变差的问题。仿真和实验证明了该方法的有效性、准确性和实时性。

高速ADC THS1207在电动车无刷直流电机中的应用

介绍了12bit同步高速模数转换器THS1207的基本原理及工作特性,重点对THS1207在电动车无刷直流电机中的应用做了具体研究,给出了相关硬件电路图和软件设计流程,为电动车无刷直流电机控制器的性能测试做了很好的准备。

核电厂基于DCS平台的控制棒控制系统棒速控制分析

为了实现核电厂基于DCS平台的数字化控制棒控制系统中棒速的控制并满足棒速控制精度要求,介绍了不同情况下实现该功能的控制算法:采用计时器功能函数或采用控制器任务区执行周期数实现;并分析了在采用任务区执行周期数来实现棒速控制时,不同任务区执行周期以及采用不同的执行周期数计算算法时对棒速精度的影响;给出了在不同算法情况下满足控制棒棒速控制要求时允许的最大的任务区执行周期。可用于指导棒速控制逻辑的编程,也可参考结论检验核电厂所选DCS平台是否满足控制棒控制系统的功能要求的条件之一。

EFFECTIVE DOUBLE LOOP CONTROL FOR A SQUARE WAVE BRUSHLESS DC MOTOR

A new type of brushless DC motor has been developed by using a square wave rare earth permanent magnet synchronous motor with its double loop control circuit. The double loop control scheme of the drive system yields a combination of desired characteristics including simplified control structure, small ripple torque, high speed accuracy, wide operating speed range, and fast dynamic response. Experimental results confirm excellent characteristics of the motor.

和利时DCS在多焦炉集气管压力系统中的应用

以鼓风机调速系统为核心的多焦炉集气管压力控制系统是一个工况复杂多变、大滞后、强耦合、非线性且频发强干扰的工业系统,结合该系统在实际生产过程中对现场仪表及生产过程控制调节的需求,设计了一套基于和利时DCS的自动控制系统。该系统完成了对焦化工艺过程的监控、控制过程参数调整、实时趋势分析、故障诊断等组态。投运结果表明,焦炉生产自动化控制水平得到提高,改善了工作环境;保证了系统可靠稳定运行。