基于降阶模型的三相Vienna整流器交流级联稳定性分析

以三相Vienna整流器交流级联稳定性为研究对象,给出了dq坐标系下三相交流系统小信号简化稳定性判据,构建了面向级联系统小信号稳定性分析的Vienna整流器阻抗方程;提出并采用一种虚拟阻抗方法,有效改善了Vienna交流级联系统小信号稳定性;构建了完整的仿真与实验模型,给出了详细的理论分析与虚拟阻抗设计方案,结果表明了所提阻抗与小信号稳定性分析的正确性。     

Unifying adaptive control with the nonlinear PI methodology: Designs for unknown strict‐feedback nonlinear systems with nonsmooth actuator nonlinearities

In this paper, we extend the nonlinear PI control methodology within an adaptive control framework. An adaptive nonlinear PI controller is proposed for output tracking of strict‐feedback nonlinear systems with nonsmooth actuator nonlinearities and unknown control directions. The current approach relaxes the standard assumption of known bounds for the associated system nonlinearities made in earlier nonlinear PI schemes. New theoretical boundedness results have been proved that enable the successful combination of backstepping and linear parametric approximators with the nonlinear PI approach and ensure semiglobal approximate tracking of the output to some reference trajectory. Following recent extensions of the nonlinear PI method to strict‐feedback systems, the intermediate virtual control laws are derived through suitable integral equations. Simulation results are also presented in this paper that verify our theoretical analysis.     

一种新型的基于单电流调节器提高永磁同步电机系统负载与抗扰能力的算法

提出了一种根据永磁同步电机(PMSM)转速来调节交轴电压的最大转矩法。算法对电压极限矢量圆与电流极限矢量圆定量分析,找到电机稳定运行时的最大转矩点,通过在电压极限矢量圆补偿定子电阻压降修正最大转矩点。通过直接给定交轴电压的方式,充分利用修正最大转矩点的电磁转矩,提高电机的负载能力和抗干扰能力。仿真验证了该算法的有效性和可行性。对于最大转矩点的定量分析,使此模型具有良好的可移植性。     

内置式永磁同步电动机弱磁调速优化控制

从永磁同步电机(PMSM)的矢量控制出发,提出了一种PMSM弱磁优化控制方法。内置式永磁同步电机(IPMSM)相对表贴式永磁同步电机弱磁能力强,调速范围宽,以IPMSM为对象,对弱磁调速进行了仿真与优化。PMSM在基速以下采用最大转矩电流比的恒转矩控制,减小了电机损耗,提高了逆变器的效率,在基速以上采用恒功率调速。直轴电流去磁调速结合交轴电流去磁调速的弱磁控制方式,提高了PMSM的功率因数,扩展了调速范围。针对弱磁环节转速的波动问题,在传统PI控制上做出改进,提出了模糊自整定PI的控制方式,提高了PMSM弱磁调速的性能。在MATLAB/Simulink中搭建仿真模型,验证了该控制方法的可行性。     

高效农用杀菌剂——烯唑醇的合成

烯唑醇是一种高效、低毒、广谱杀菌剂，并具有良好的植物生长调节活性。本文介绍了以α－三唑频那酮为起始原料合成该产品的工艺路线、合成方法、影响工艺条件的因素等。     

生产管理系统的应用

介绍了宁夏西部聚氯乙烯有限公司生产管理系统的构成，基于PI数据库的生产管理系统为及时监控各套生产装置的生产运行情况，合理调配资源，科学组织生产提高效益做出了贡献。     

调节剂增量加入对SBR1502性能的影响

研究了增量加入调节剂ｔ－Ｃ１２ｈ２５ＳＨ对单体转化率为７０％的ＳＢＲ１５０２分子参数的调节作用。结果表明，当增量：初加量为２５：７５（质量比），增量加入时的转化率为３０％－４５％时，聚合物的分子量，分子量分布，门尼粘度，凝胶含量均可行进行有效控制；所得产品的物理机械性能达到或超过了ＪＳＲ１５０２及Ｎｉｐｏｌ１５０２的指标。     

全位置自动焊机焊枪摆动系统平稳性研究

焊枪摆动系统的速度平稳性是焊接质量的重要保障。针对摆动系统低速运行特点,为了解决静摩擦和库伦摩擦给伺服系统带来的稳态误差和低速爬行问题,依据仿真通过增大比例增益来减轻低速爬行现象,提出了变参数的PI控制方案。经过对伺服电机实际测量得到低速爬行的速度范围,通过固定参数与变参数控制器速度响应对比,证实了增大比例增益能够减轻低速爬行问题,提高伺服控制系统运动性能。     

Optimal Control of Nonlinear Inverted Pendulum System Using PID Controller and LQR: Performance Analysis Without and With Disturbance Input

Linear quadratic regulator(LQR) and proportional-integral-derivative(PID) control methods, which are generally used for control of linear dynamical systems, are used in this paper to control the nonlinear dynamical system. LQR is one of the optimal control techniques, which takes into account the states of the dynamical system and control input to make the optimal control decisions.The nonlinear system states are fed to LQR which is designed using a linear state-space model. This is simple as well as robust. The inverted pendulum, a highly nonlinear unstable system, is used as a benchmark for implementing the control methods. Here the control objective is to control the system such that the cart reaches a desired position and the inverted pendulum stabilizes in the upright position. In this paper, the modeling and simulation for optimal control design of nonlinear inverted pendulum-cart dynamic system using PID controller and LQR have been presented for both cases of without and with disturbance input. The Matlab-Simulink models have been developed for simulation and performance analysis of the control schemes. The simulation results justify the comparative advantage of LQR control method.     

基于PIC单片机的拧紧机构控制器的研究

设计了一种基于PIC单片机的无刷直流电机控制系统,采用PI调节的控制方法,实现了对直流电机转速的控制。并将控制系统应用到活塞螺母拧紧机上,作为拧紧机执行机构的控制器。文中给出了设计的总体框图,部分硬件电路图和控制软件流程图。试验结果表明,此系统能够满足活塞螺母拧紧机的设计要求。