Inductor Current Sampled Feedback Control of Chaos in Current-Mode Boost Converter

A chaos control strategy for chaotic current-mode boost converter is presented by using inductor current sampled feedback control technique.The quantitative analysis of control mechanism is performed by establishing a discrete alterative map of the controlled system.The stability criterion,feedback gain,and corresponding critical duty ratio are obtained from the eigenvalue of the map.The simulation results verify the t heoretical analysis results of the control strategy.

Feedback Control of Plasma Current and Horizontal Position in HT-7

There is a strong magnetic coupling between poloidal field coils of superconducting tokamak HT-7, especially between ohinic heating and vertical field coils. These coils are connected to individual power supply. The control system for the plasma current and horizontal position control has been designed and showed satisfactory results with the feedback control of multivari- able feedforward-decoupling and var-parameter PID controller to simultaneously modulate power supplies. The design and analysls of the control system is presented.

Controlling Beam Halo-Chaos via Time-Delayed Feedback

The study of controlling high-current proton beam halo-chaos has become a key concerned issue for manyimportant applications. In this paper, time-delayed feedback control method is proposed for beam halo-chaos. Particle incell simulation results show that the method is very effective and has some advantages for high-current beam experimentsand engineering.

Control of Halo-Chaos in Beam Transport Network via Neural Network Adaptation with Time-Delayed Feedback

在横梁运输网络(隧道) 的光圈混乱控制的题目为高水流的质子横梁 since1990' 的许多重要应用程序成为了一个关键担心的问题。在这篇论文，磁场适应控制基于神经网络，推迟 withtime 的反馈为与周期的集中的隧道在横梁运输网络压制横梁光圈混乱被建议。高水流的质子横梁的信封半径被控制由合适选择控制结构和神经网络的参数到达匹配的横梁半径，调整延期时间和神经网络的控制系数。

Feedback Control System for Antenna Phase Difference in the LHCD Experiments

It is well accepted that lower hybrid current drive （LHCD） is the most efficient method for non-inductive current drive in fusion devices and the effect of the current drive is dependent on not only microwave power but also its grill phase shift. This paper presents a new kind of feedback control system for antenna phase difference in LHCD experiments. In this highspeed control system, a lot of new technologies and methods are incorporated. The results of the experiments show a very good agreement with the system design.

The Novel Current Control for Virtual Synchronous Generator

In recent years, power generation using renewable energy sources has been developed as a solution to the global warming problem. Among these power generation methods, wind power generation is increasing. However, as the penetration level of wind power generation increases, the low inertia and lack of synchronous power characteristics of the penetrated power system can have a significant impact on the transient stability of the grid. The virtual synchronous generator provides the ability of virtual inertia and synchronous power to interconnected inverters. The interconnected inverter with the virtual synchronous generator ability uses, in general, PI control based current controller. This paper proposes a new current-control method and compares it with conventional methods. The proposed current control is a method that follows virtual synchronous generator model that changes every moment by solving the discrete-time linear quadratic optimal control problem for each sampling time interval. The new method follows the conventional method, and therefore the reactive power fluctuation can be suppressed and the interconnected inverter will be downsized.

Control of magnetic levitation positioning stage with an eddy current damper

To enhance the system damping,a permanent magnet set which served as an eddy current damper was added to the magnetic levitation positioning stage which consists of a moving table,four Halbach permanent magnetic arrays,four stators and displacement sensors.The dynamics model of this stage was a complex nonlinear,strong coupling system which made the control strategy to be a focus research.The nonlinear controller of the system was proposed based on the theory of differential geometry.Both simulation and experimental results show that either the decoupling control of the movement can be realized in horizontal and vertical directions,and the control performance was improved by the damper,verifying the validity and efficiency of this method.

Two Simple Analog Multiplier Based Linear VCOs Using a Single Current Feedback Op-Amp

Two simple voltage-controlled-oscillators (VCO) with linear tuning laws employing only a single current feedback operational amplifier (CFOA) in conjunction with two analog multipliers (AM) have been highlighted. The workability of the presented VCOs has been demonstrated by experimental results based upon AD844 type CFOAs and AD534 type AMs.

某型地面发控点火电流异常分析和电路改进

针对某型地面发控系统在使用过程中出现的点火电流异常问题,采用数学方法研究点火电流与元器件参数的变化规律,发现地面发控点火电流在某些环境下不稳定的根本原因。最后提出一种闭环控制方案,增加电流反馈环节,解决点火电流异常问题。实际应用验证表明,改进后的点火电路能适应更大的点火负载,有效提高了点火的可靠性。

图腾柱功率因数校正器的二自由度控制分析

TPFC一般采用一自由度输出电压控制,在负载变化时输出电压动态特性较差,且启动过程存在明显超调。本文在推导TPFC双闭环控制结构基础上,引用了负载电流前馈控制和输出电压反馈补偿控制,构成两种二自由度(2DOF)控制结构。仿真分析表明,负载电流前馈型2DOF控制可以有效抑制负载变化引起的输出电压波动,但启动过程超调明显;输出电压反馈补偿型2DOF控制可以实现输出电压无超调启动,但是抑制负载变化的能力较差;综合负载电流前馈型和输出电压反馈补偿型的2DOF控制获得满意的输出电压控制效果,表现为启动过程无超调和变载过程无波动。

永磁同步电机扩展卡尔曼滤波器电流观测方法

为提高前置电感电容LC滤波器永磁同步电机系统性能,提出一种基于扩展卡尔曼滤波器(extended Kalman filter,EKF)的电机电流观测控制方法。该方法采集逆变器侧电流,通过新型EKF观测器获得实际电机电流,并将估计的电机电流用于电流环反馈控制。论文给出了新型EKF电流观测器的结构和参数设计过程,并利用Lyapunov稳定性定理证明了该方法的稳定性。仿真结果表明,与传统Luenberger观测器相比,新型EKF观测方法的电流估计误差更小,电机电流跟踪性能更好,电磁转矩脉动及其谐波明显降低。

混合级联直流输电系统整流/逆变不同控制回路动态交互作用与稳定性研究

为了研究混合级联直流输电系统整流侧和逆变侧各换流器控制系统间的交互作用,文中首先建立混合级联直流输电系统的状态空间模型,并推导得到系统的多输入多输出传递函数模型。然后针对不同的研究目标,根据单通道分析设计理论建立等效单输入单输出反馈控制模型;在此基础上,分离出不同控制回路的耦合控制通道,定量评估系统强度、逆变侧交流联络线与控制参数等对控制回路间交互作用的影响。理论分析表明,当整流侧或逆变侧交流系统强度降低时,两侧控制回路间交互作用增强;当交流联络线长度缩短时,逆变侧电网换相换流器(line commutated converter,LCC)和模块化多电平变换器(multilevel modular converter,MMC)控制回路间的动态交互增强,各控制环节参数之间存在相互制约关系。最后,在PSCAD/EMTDC上搭建混合级联直流输电系统的电磁暂态详细仿真模型,验证所建立单输入单输出反馈控制模型及上述理论分析结果的正确性。

多挡位电流比较仪研究

针对传统的电流比较仪均采用人工操作,自动化程度和检测效率低的问题,设计了多挡位电流比较仪。采用嵌入式单片机控制技术,智能化测量检测绕组信号,自动输出测试数据,实现了自主跟随,负反馈智能控制,提高了工作效率及测试精度。

Design of Controller for New EAST Fast Control Power Supply

The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.

A Configuration for Realizing Voltage Controlled Floating Inductance and Its Application

A configuration using current feedback amplifiers AD844 and multiplier AD534 has been presented, which is capable of realizing Voltage Controlled Floating Inductance (proportional and in-verse proportional). The application of band pass filter in Figure 4(a), notch filter in Figure 5(a) and Hartley oscillator in Figure 6(a) and simulation result in Figures 4(b)-(d), Figures 5(b)-(d), Figures 6(b)-(d) shows the workability of proposed configuration.

弱电网下LCL型并网逆变器的改进稳定性控制方法

弱电网下并网点电压谐波和电网阻抗不可忽略。LCL型并网逆变器考虑电网阻抗后会发生谐振频率平移现象,同时并网点电压谐波会影响电压前馈控制效果。文章在并网电流结合电容电流反馈的基础上,通过修改电容电流反馈系数应对电网阻抗,提出了一种查表法的电容电流反馈系数选取方法。通过多谐振并网点电压前馈控制通道的控制器应对电压谐波。实验验证了文章所提改进稳定性控制方法的有效性。

Canonic Realizations of Voltage-Controlled Floating Inductors Using CFOAs and Analog Multipliers

New voltage-controlled floating inductors employing CFOAs and an analog multiplier have been presented which have the attractive features of using a canonic number of passive components (only two resistors and a capacitor) and not requiring any component-matching conditions and design constraints for the intended type of inductance realization. The workability and applications of the new circuits have been demonstrated by SPICE simulation and hardware experimental results based upon AD844-type CFOAs and AD633-type/MPY534 type analog multipliers.

基于改进电容电流反馈的含非线性负载光伏并网系统振荡抑制策略

在含非线性负载的光伏并网系统中,光伏发电单元、非线性负载、电网三者之间的相互作用可能导致系统出现振荡,因此提出一种改进的电容电流反馈有源阻尼(capacitor current feedback active damping, CCFAD)控制方法。首先,采用谐波线性化方法建立含非线性负载的光伏并网系统序阻抗模型,并基于阻抗模型和对数频率稳定判据揭示含非线性负载的光伏并网系统振荡特性。随后,基于负电阻理论定义阻抗相对灵敏度指标,评价不同参数变化对系统阻抗特性的影响程度,获取影响系统稳定性的关键参数。基于不同参数的阻抗相对灵敏度分析,提出一种改进的CCFAD方法。该方法拓展了传统CCFAD的正阻尼区域,有效地改善了系统输出阻抗的相位裕度,提高了系统稳定性。最后,在Matlab/Simulink中搭建仿真模型,验证了分析方法的正确性和所提控制策略的有效性。

弱电网下抑制谐波谐振的LCL型并网逆变器鲁棒性CCFAD方法

LCL型并网逆变器采用电容电流反馈有源阻尼在弱电网下进行并网电流控制时,如果系统环路谐振频率高于1/6的采样频率,数字控制延时会导致并网逆变器在较宽范围变化的电网阻抗影响下鲁棒性较差甚至失稳。通过分析指出,电容电流反馈有源阻尼环路可等效为并联在滤波电容两端的虚拟阻抗Zeq(s),表现出的负阻特性是造成系统失稳的主要原因。鉴于此,提出一种采用负一阶惯性环节进行电容电流反馈有源阻尼的鲁棒性方法,在电容电流阻尼环路中引入惯性环节,利用频率稳定性分析对所提方法进行详细论述,并给出相关参数的设计过程。理论分析表明,该方法可保证Zeq(s)在LCL滤波器谐振频率有效范围内始终处于正阻特性范围,不仅提高系统的稳定裕度,并网系统的谐波谐振也得到抑制。此外,该方法具有较好的灵活性,当采用电容电压反馈有源阻尼控制并进行锁相时,可节省一组电流传感器的使用。最后,通过实验验证了所提方法的有效性。

静止无功补偿器的小波神经网络PID控制方法研究

静止无功补偿器(SVC)是电力系统中应用广泛的动态无功补偿装置。针对传统比例积分微分(PID)在SVC动态调节过程中由于控制器参数固定而存在动态响应、自适应能力差的问题,提出了一种基于小波神经网络PID(WNNPID)的SVC电流反馈电压稳定控制方法。首先,分别选取SVC的电压差ΔUr、电压误差ΔU和补偿电压USL作为WNNPID控制器的输入信号,而控制器的输出为SVC的参考电纳。然后,采用小波神经网络(WNN)和增量式PID控制对WNNPID控制器的结构进行设计。最后,采用Matlab/Simulink仿真平台对所提控制方法进行仿真,并与基于反向传播(BP)神经网络PID的控制效果进行了对比。仿真结果表明,所提WNNPID控制方法具有更稳定的电压控制效果、较快的响应速度、较好的动静态响应性能和较强的自适应能力。