三相电压暂变主电路拓扑及其检测方法的研究

提出了一种三相电压暂变补偿的主电路拓扑。针对此方案对三相电压暂变进行独立补偿,提出一种单—三相检测方法,通过将各相电压变换,实现了对三相电压的独立检测。给出了检测方法的基本原理,并对其进行了动态性能分析。最后,得出了此检测方法的仿真结果。     

10kV电压扰动装置主电路设计及稳态运行特性

为了检测电能质量补偿装置在电能质量扰动情况下的性能,文章提出了适用于10kV电压等级的多功能电压扰动发生器的主电路结构设计方案,采用H桥级联的拓扑结构,将该装置直接串联在线路,形成了电压扰动发生源。结合该装置主电路拓扑,研究了装置的稳态运行特性,利用PSCAD/EMTDC软件对装置稳态运行特性进行了仿真,仿真结果验证了该装置主电路设计方案的可行性。     

三相四开关整流器的研制

三相四开关整流器拓扑具有功率器件少、成本低、装置体积小、效率高和开关损耗低等优点,同时又可作为三相六开关整流器故障时的容错拓扑,因此三相四开关整流器受到广泛关注.本文首先介绍了三相四开关整流器的主电路,并且提出一种电流前馈型解耦的电压电流双闭环控制策略.为了抑制直流侧两电容电压不平衡的情况,采用了一种前馈补偿的控制策略...     

三相电压型PWM整流器设计

本文在对比了电压型和电流型PWM整流器的基础上,采用模块化设计思想设计了一种具有工程实用性的三相电压型PWM整流器,包括主电路、驱动电路、检测电路及保护电路的设计,并利用MATLAB进行相关仿真,仿真结果表明本方案达到提高功率因素的目的。     

永磁同步电机矢量控制中死区补偿技术的研究

本文针对永磁同步电机矢量控制系统,分析了死区电压矢量对三相输出电压的影响以及死区电压矢量与定子电流方向的关系,提出了一种基于SVPWM矢量控制的死区补偿方法。定子电流矢量角根据计算得出,避免了传统方法在相电流过零处由于电流方向检测不准而影响补偿效果。该方案无需增加硬件电路,对软件进行修改即可实现。仿真试验结果证实了该方法的有效性。     

电力有源补偿及滞环电流跟踪控制研究

本文在对电力系统有源无功与谐波补偿的原理进行理论分析的基础上,运用其有关分析结果主要讨论一种电力有源滤波器主电路及变结构非线性控制系统的组成和工作原理,给出了一种变结构滞环电流跟踪控制的思路,通过Pspice软件对单相和三相系统进行了仿真研究,仿真结果证实了该系统及控制方法的正确性与可行性。     

三相电压型准阻抗源AC～AC变换器

摘要：为了克服传统三相斩控式交流调压器的不足,提出了一种三相电压型准阻抗源变换器电路拓扑。研究了其拓扑结构和工作原理,推导了输出电压与占空比的定量关系。运用matlab对电路进行了仿真,并根据仿真结果建立了实验电路,采用脉冲宽度调制法（PWM）对电路进行总体控制,得到占空比为0.2与0.8时的三相电压波形。实验结果验证了三相电压型准阻抗源电压调节的的可靠性和可行性。     

基于单片机与TC787芯片的三相半控整流电路设计

整流电路广泛应用在直流电机调速,直流稳压电压等场合。而三相半控整流桥电路结构是一种常见的整流电路,其容易控制,成本较低。本文中介绍了一种基于PIC690单片机与专用集成触发芯片TC787的三相半控整流电路,它结合专用集成触发芯片和数字触发器的优点,获得了高性能和高度对称的触发脉冲。它充分利用单片机内部资源,集相序自适应、系统参数在线调节和各种保护功能于一体,可用于对负载的恒电压控制。主电路采用了三相半控桥结构,直流侧采用LC滤波结构来提高输出的电压质量。     

三相四线制无功与谐波全补偿的并联有源电力滤波器的研究

简要分析了并联有源电力滤波器的工作原理,选取含有裂相电容的三桥臂电压源型逆变器作为系统主电路,输出电流采用动态滞环控制。针对三相四线系统,且考虑到电网电压畸变和不对称的情况,给出了一种基于瞬时功率理论实现无功功率和谐波全补偿的控制策略,并使用Matlab对系统进行了仿真。     

三相四线制无功与谐波全补偿的并联有源电力滤波器的研究

简要分析了并联有源电力滤波器的工作原理，选取含有裂相电容的三桥臂电压源型逆变器作为系统主电路，输出电流采用动态滞环控制。针对三相四线系统，且考虑到电网电压畸变和不对称的情况，给出了一种基于瞬时功率理论实现无功功率和谐波全补偿的控制策略，并使用Matlab对系统进行了仿真。     

一种递归模糊神经网络自适应控制方法

构造了一种递归模糊神经网络(RFNN),该RFNN利用递归神经网络实现模糊推理,并通过在网络的第一层添加了反馈连接,使网络具有了动态信息处理能力.基于所设计的RFNN,提出了一种自适应控制方案,在该控制方案中,采用了两个RFNN分别用于对被控对象进行辨识和控制.将所提出的自适应控制方案应用于交流伺服系统,并给出了仿真实验结果,验证了所提方法的有效性.     

Robust force control based on compensation for parameter variationsof dynamic environment

Force control strategies that are robust against disturbance and parameter variations are proposed. These strategies are expansions of disturbance observer-based control strategy, and require little computation. Observers are proposed that estimate parameter variations of the dynamic environment on which the force is imposed are introduced. Since the observer-based control represents a nominal system, a second derivative of force can be controlled. A force control strategy for controlling the second derivative of force is also proposed. The force response similar to the force command is realized by these strategies in spite of the disturbance and the parameter variations of the control object. The effectiveness of the proposed methods is confirmed by simulation and experimental results     

A new state feedback control of resonant converters

A state feedback control that can be easily implemented is proposed to improve the stability and dynamic characteristics of resonant power converters. An important characteristic of the system with the proposed control is the reduction of order in the discrete time domain. The design parameters of the control are reduced by one, compared with those of the conventional linear state feedback control, and the design procedure is similar to that of a variable structure system (VSS) control. The proposed control is illustrated by its application to a series resonant power converter. The experimental results confirm the validity of the proposed control     

多重化有源电力滤波器的研制

分析了多重化大功率有源电力滤波器的基本结构及控制系统的构成,采用一种基于负载基波电流作为参考电流的控制模式,提出了在该模式下多模块并联时的均流控制方法.应用该方法设计基于DSP和CPLD的数模混合控制系统,给出了采用该系统的二重化有源电力滤波器的实验结果,结果表明,能有效补偿非线性负载产生的谐波,具有很好的补偿效果.     

An RMRAC Current Regulator for Permanent-Magnet Synchronous Motor Based on Statistical Model Interpretation

A new robust model reference adaptive control (RMRAC) scheme for the current regulation of a permanent-magnet synchronous motor (PMSM) is proposed in a synchronous frame, which is completely free from the control performance degradation caused by parameter uncertainties. The current regulator of the PMSM is the innermost loop of its electromechanical driving system and plays an important role in the control hierarchy. When the PMSM runs precisely at high speeds, the cross-coupling terms must be compensated for. In the proposed RMRAC, the input signal is composed of the control voltage obtained by the model reference adaptive control (MRAC) law and the output of the disturbance estimator. The gains of the feedforward and feedback controllers are estimated by the proposed modified gradient method, where the system disturbances are filtered out by the estimated current regulation error. A voltage corresponding to the estimated system disturbances is fed forward to the control input in order to filter out the disturbances. The proposed method compensates the cross-coupling terms in a synchronous current model regardless of parameter variations. It also shows a good real-time performance due to the simplicity of control structure. Through simulations and real experiments, the efficiency of the proposed method is verified.     

Motion control algorithms based on the dynamic modelling of kinematically redundant hybrid parallel robots

This paper discusses the motion control problem of kinematically redundant hybrid parallel robots that were recently proposed. The kinematic and dynamic models are firstly reviewed. It is pointed out that the robot can be decomposed into two parts and that each part can be analysed independently. A new hybrid approach is proposed based on this property of the robot. This approach includes an adapted computed-torque control scheme for the legs that operates in the joint space as well as a compensation of the errors of the platform applied in the Cartesian space. The convergence of this proposed approach is also verified using the Lyapunov stability theory. Two example architectures of kinematically redundant robots are built and experiments are conducted. Finally, the results are compared and analysed in order to validate the improvements provided by the proposed control method. It is shown that the proposed control scheme significantly reduces the position error. Potential extensions of this work are also discussed.     

Robust PID control of fully-constrained cable driven parallel robots

In this paper dynamic analysis and robust PID control of fully-constrained cable driven parallel manipulators are studied in detail. Since in this class of manipulators cables should remain in tension for all maneuvers in their workspace, feedback control of such robots becomes more challenging than that of conventional parallel robots. In this paper, structured and unstructured uncertainties in dynamics of the robot are considered and a robust PID controller is proposed for the cable robot. To ensure that all cables remain in tension internal force concept is used in the proposed PID control algorithm. Then, robust stability of the closed-loop system with proposed control algorithm is analyzed through Lyapunov direct method and it is shown that by suitable selection of the PID controller gains, the closed-loop system would be robustly stable. Finally, the effectiveness of the proposed PID algorithm is examined through experiments on a planar cable driven robot and it is shown that the proposed control structure is able to provide suitable performance in practice.     

Perfect tracking control based on multirate feedforward controlwith generalized sampling periods

In this paper, a novel perfect tracking control method based on multirate feedforward control is proposed. The advantages of the proposed method are that: (1) the proposed multirate feedforward controller eliminates the notorious unstable zero problem in designing the discrete-time inverse system; (2) the states of the plant match the desired trajectories at every sampling point of reference input; and (3) the proposed controller is completely independent of the feedback characteristics. Thus, highly robust performance is assured by the robust feedback controller. Moreover, by generalizing the relationship between the sampling period of plant output and the control period of plant input, the proposed method can be applied to various systems with hardware restrictions of these periods, which leads to higher performance. Next, it is shown that the structure of the proposed perfect tracking controller is very simple and clear. Illustrative examples of position control using a DC servomotor are presented, and simulations and experiments demonstrate the advantages of this approach     

A new instantaneous torque control of PM synchronous motor forhigh-performance direct-drive applications

A new instantaneous torque-control strategy is presented for high-performance control of a permanent magnet (PM) synchronous motor. In order to deal with the torque pulsating problem of a PM synchronous motor in a low-speed region, new torque estimation and control techniques are proposed. The linkage flux of a PM synchronous motor is estimated using a model reference adaptive system technique, and the developed torque is instantaneously controlled by the proposed torque controller combining a variable structure control (VSC) with a space-vector pulse-width modulation (PWM). The proposed control provides the advantage of reducing the torque pulsation caused by the nonsinusoidal flux distribution. This control strategy is applied to the high-torque PM synchronous motor drive system for direct-drive applications and implemented by using a software of the digital signal processor (DSP) TMS320C30. The simulations and experiments are carried out for this system, and the results demonstrate the effectiveness of the proposed control     

Generalized digital redesign method for linear feedback systembased on N-delay control

A new digital redesign method is proposed for feedback control systems, by which the states in the continuous-time system are completely reserved in the redesigned sampled-data system. The features of the proposed method are: 1) the N-delay control is employed, and the lth plant input is changed N_l times during one sampling period; 2) the states of the redesigned sampled-data system completely match those of the original continuous-time closed-loop system at every sampling period; and 3) the proposed redesign method can be applicable for a static state-feedback and/or a dynamic controller. An illustrative example of position control using a DC servo motor is presented. The advantages of the proposed redesign approach are demonstrated both in the time and frequency domains