Robust Nonlinear Current Sensorless Control of the Boost Converter with Constant Power Load

The boost converter feeding a constant power load (CPL) is a non-minimum phase system that is prone to the destabilizing effects of the negative incremental resistance of the CPL and presents a major challenge in the design of stabilizing controllers. A PWM-based current-sensorless robust sliding mode controller is developed that requires only the measurement of the output voltage. An extended state observer is developed to estimate a lumped uncertainty signal that comprises the uncertain load power and the input voltage, the converter parasitics, the component uncertainties and the estimation of the derivative of the output voltage needed in the implementation of the controller. A linear sliding surface is used to derive the controller, which is simple in its design and yet exhibits excellent features in terms of robustness to external disturbances, parameter uncertainties, and parasitics despite the absence of the inductor’s current feedback. The robustness of the controller is validated by computer simulations.

Application of a Current and Voltage Mixed Control Mode for the New Fast Control Power Supply at EAST

A feedback control system is needed to restrain plasma vertical displacement in EAST （Experimental Advanced Superconducting Toknmak）. A fast control power supply excites active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, new demands on the new fast control power supply have led to an enhanced ability of fast response and output current, as well as a new control mode. The structure of cascaded and paralleled H-bridges can meet the demand of extended capacity, and digital control can reMize current and voltage mixed control mode. The validity of the proposed scheme is confirmed by experiments.

A Synthesis of Electronically Controllable Current-Mode PI, PD and PID Controllers Employing CCCDBAs

This paper presents a synthesis of current-mode PI, PD and PID controllers employing current controlled current differential buffer amplifiers (CCCDBAs). The features of these controllers are that: the output parameters can be electronically/independently controlled by adjusting corresponding bias currents in the proportional, integral, and deviation controllers;circuit description of the PID controller is simply formulated, it consists of four CCCDBAs cooperating with two grounded capacitors, and PI and PD controllers are composed of three CCCCDBAs and a grounded capacitor. Without any external resistor, the proposed circuits are very suitable to develop into integrated circuit architecture. The given results from the PSpice simulation agree well with the theoretical anticipation. The approximate power consumption in a closed loop control system consisting of the PI, PD and PID controller with low-pass filter passive plant are 4.03 mW, 4.85 mW and 5.71 mW, respectively, at ±1.5 V power supply voltages.

An Improved Non-isolated LED Converter with Power Factor Correction and Average Current Mode Control

A new type of high power LED drivers is proposed by adopting an improved two-stages non-isolated configuration. In order to improve power factor and achieve accurate average current control under universal input voltages ranging from 100 Vrms to 240 Vrms, the power factor correction and average current mode control methods operating in continuous current conduction mode are designed and implemented. With the LUMILEDS emitter type LEDs, a laboratory prototype is built and measured. And from the measured results, it could be concluded that the proposed driver has many better performances such as high power factor, low current harmonic, accurate average current control and switch protection.

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.

Digital close loop control system for current-programmed mode arc welding inverter

A small-signal model of current programmed mode pulse width modulation converter including the equivalent sampling effect is introduced and analyzed. In this model, an addition pole is brought out by the sampling effect in the current loop gain, and it affects dynamic bandwidth and stability of the inner current loop. By selecting the appropriate stability parameter which determines the additional pole and describes the degree of peaking in closed loop transfer function, a control model of current programmed full bridge arc welding inverter with maximum frequency bandwidth and stability can be obtained. Small and large amplitude pulse current outputs are employed in simulations and experiments and results validate the design method.

Current Mode Universal Filter Using Single Current Controlled Differential Difference Current Conveyor Transconductance Amplifier

This research paper contains a new electronically tunable current-mode biquadratic universal filter using a new active building block;current controlled differential difference current conveyor transconductance amplifier (CCDDCCTA). The proposed filter provides the following important and desirable features: (i) One can use only one CCDDCCTA and two capacitors;(ii) One can get low pass (LP), band pass (BP), high pass (HP), notch (NF) and all pass (AP) current responses from the same configuration without any alteration;(iii) Passive components are grounded, which ease the integrated circuit implementation;(iv) Responses are electronically tunable;and (v) Sensitivity is low. Moreover, the non-ideality analysis shows that the parasitic passive components can be compensated for the proposed circuit. The functionality of the design is verified through SPICE simulations using 0.25 μm CMOS TSMC technology process parameters. Simulation result agrees well with the theoretical analysis.

Loop-Shaping Based Control for Switch Mode DC-DC Power Converters

Renewable energy sources require switching regulators as an interface to a load with high efficiency, small size, proper output regulation, and fast transient response. Moreover, due to the nonlinear behavior and switching nature of DC-DC power electronic converters, there is a need for high-performance control strategies. This work summarized the dynamic behavior for the three basic switch-mode DC-DC power converters operating in continuous conduction mode, i.e. buck, boost, and buck-boost. A controller was designed using loop-shaping based on current-mode control that consists of two feedback loops. A high-gain compensator with wide bandwidth was used in the inner current loop for fast transient response. A proportional-integral controller was used in the outer voltage loop for regulation purposes. A procedure was proposed for the parameters of the controller that ensures closed-loop stability and output voltage regulation. The design-oriented analysis was applied to the three basic switch-mode DC-DC power converters. Experimental results were obtained for a switching regulator with a boost converter of 150 W, which exhibits non-minimum phase behavior. The performance of the controller was tested for voltage regulation by applying large load changes.

永磁直线同步电机改进预测电流控制

永磁直线同步电机(PMLSM)预测电流控制(PCC)时存在易受参数变化和延迟以及负载扰动影响,为此提出基于二阶超螺旋滑模观测器(STSMO)的改进型PCC。首先,建立包含不确定性的PMLSM动态数学模型。然后,为了补偿参数变化以及延迟的影响,采用二阶STSMO估计下一周期的电流和参数变化造成的扰动电压,估计值用以计算下一周期的给定电压,以提高电流跟踪精确度,通过李雅普诺夫函数证明观测器的稳定性。同时,采用基于改进指数趋近律的自适应滑模控制器(ASMC)对速度进行跟踪,将状态变量和滑模面加入到指数趋近律中,不仅削弱了电流抖振,且进一步提升了系统的鲁棒性。半实物仿真实验结果表明,与传统PCC相比,提出方法能有效地抑制不确定性对系统影响,使系统具有更好的跟踪性能和鲁棒性。

三相有源电力滤波器重复滑模控制

有源电力滤波器(active power filter,APF)的谐波电流控制直接影响着APF的滤波效果。针对指数趋近率容易产生抖振的问题,提出了一种变指数趋近率,并在dq坐标系下推导出了基于该变指数趋近率的APF滑模控制律。为提高APF对高次谐波的追踪能力,将重复控制和基于变指数趋近率的滑模控制并联,提出了一种APF的重复滑模控方法。仿真结果表明,相对于基于指数趋近率的滑模控制方法,提出的重复滑模控制方法具有更高的稳态精度,电网电流的谐波畸变率更低。

基于二阶滑模扰动观测的PMSM电流预测控制研究

针对无差拍电流预测控制(DPCC)对电机参数的依赖性,系统性能尤其易受电感参数影响的问题,研究基于二阶滑模扰动观测的永磁同步电机(PMSM)电流预测控制方法。首先,根据滑模控制原理分析电感参数失配对系统参数鲁棒性的影响,及传统滑模控制的不连续函数导致的系统“抖振”;然后,在DPCC中引入一种基于二阶趋近律的滑模扰动观测器(SMDO),实时补偿电感参数失配造成的扰动,同时通过二阶趋近律加速扰动误差的收敛;最后,将该方法与DPCC、SMDO+DPCC进行对比仿真实验。实验结果表明,在电感参数失配的情况下,该方法降低了电流稳态误差,提高了系统参数的鲁棒性,减少了传统滑模控制带来的系统“抖振”现象。

永磁同步电机新型趋近律滑模控制器设计

针对传统指数趋近律因函数不连续性引起抖振、趋近速度与抖振抑制之间无法同时满足高性能控制系统要求的问题,提出基于系统状态变量的新型滑模趋近律,并应用于永磁同步电机速度、电流控制器中。趋近律引入系统状态变量幂次项和状态变量的双曲正弦值,使系统状态变量以等速和指数2种速率趋向切换面,可以加快系统到达切换面的速度,当系统接近切换面时,指数项接近于0,等速项开始起关键作用,对系统的抖振进行抑制。同时采用双曲正切开关函数替代符号函数,以去除因函数的不连续性所引起的抖振问题。既能提高系统到达滑模面的速度,又能有效抑制固有抖振,提升系统的动态性能。仿真和实验结果表明,新型趋近律相比于传统指数趋近律能够有效降低永磁同步电机启动时转速超调,提高系统的响应速度,抑制系统的抖振。

基于电流源和电压源的储能系统双模式控制策略研究

本文针对储能系统在电网辅助服务(调频)、差价套利、新能源发电功率管理等不同应用场景下的适应性问题,提出了一种基于电流源和电压源的双模式切换策略。该策略采用基于PI的电压和相位预同步补偿及虚拟阻抗软限流策略解决并网时可能造成的系统过流冲击。此外,通过对电压控制积分器进行复位和数据切换,实现了模式间的无缝切换;通过在Simulink仿真软件中搭建储能微网模型,对其在并网运行、离网运行、离并网转换、多机并联等典型工况进行了仿真验证。验证表明,该控制策略能够满足并离网要求,而且在多机并联时具备黑启动能力,启动完成后将自动转入并网运行。

预测控制与滑模控制结合的永磁同步电机控制

提出一种改进型无差拍预测电流控制方法与改进型滑模控制方法结合的控制策略。基于永磁同步电机的数学模型,构建电流内环控制算法,设计扩张状态观测器,解决无差拍预测电流控制因参数扰动及模型失配导致的电流误差问题。速度外环设计一种超局部模型滑模控制器,设计滑模扰动观测器削弱滑模抖振。仿真结果证明,结合后的控制方法有效提高了电机暂、稳态性能,提升了系统抗干扰能力、鲁棒性及响应速度。

一种应用于探测的可预测电流模式FSBB电路

探测器的能源供给离不开DC-DC变换器,先进的控制方法能提高工作效率。预测电流模式控制相比于传统的PI控制具有动态响应快、易于进行过流保护等优点,因此被广泛应用到电力电子控制领域。由于控制回路的问题,不能通过计算开环增益的方式对负载波动与输出电压变化的闭环传递函数进行有效地设计。因此,提出了一种在不加前馈控制的情况下,基于预测电流模式控制四开关Buck-Boost(four-switch Buck-Boost,FSBB)变换器补偿器的设计方案,该方法能提升负载动态响应,通过实验数据,证明了该方法的有效性。

High Frequency Oscillator Design Using a Single 45 nm CMOS Current Controlled Current Conveyor (CCCII+) with Minimum Passive Components

In the field of analog VLSI design, current conveyors have reasonably established their identity as an important circuit design element. In the literature published during the past few years, numerous application have been reported which are based on a variety of current conveyors. In this paper, an oscillator circuit has been proposed. This oscillator is designed using a single positive type second generation current controlled current conveyor (CCCII+). A CCCII has parasitic input resistance on it’s current input node. This resistance could be exploited to reduce circuit complexities. Thus in this accord, a novel oscillator circuit is proposed which utilizes the parasitic resistance of the CCCII+ along with a few more passive components.

基于ESO的PMSM无模型快速超螺旋滑模预测控制

为提高表贴式永磁同步电机(Surface permanent magnet synchronous motor,SPMSM)在参数变化和外部扰动下的鲁棒性,提出一种基于扩张状态观测器的无模型快速超螺旋滑模预测控制方法。首先,建立SPMSM参数摄动时的新型超局部模型。其次,采用改进的超螺旋算法作为辅助控制率设计转速环无模型超螺旋滑模反馈控制器,同时利用复合的扩张扰动观测器估计超局部模型中的未知部分,并通过Lyapunov稳定性理论证明了控制器和观测器的稳定性。电流环应用无差拍电流预测控制策略,结合扩张状态观测器对扰动量进一步估计并进行前馈补偿,使电流环具有更好的动态响应和更小的谐波分量。仿真试验结果表明,所提方法可有效提高系统响应速度,改善SPMSM在发生参数漂移和外部扰动下的暂稳态性能,降低电流总谐波畸变率,提升系统鲁棒性和抗干扰性能。

IF-ZVVCD与SMO的PMSM无位置传感器全速域复合控制

针对永磁同步电机(PMSM)全速域无位置传感器控制中,零低速阶段的高频注入法会引起转矩脉动、噪声等问题,提出一种IF控制结合零电压矢量电流微分法(ZVVCD)实现电机零低速运行,并与改进滑模观测器法复合达到全速域无位置传感器控制目标。在零低速阶段,IF控制法启动电机并在低速切换为ZVVCD,减小转速波动,提高控制精度;在中高速阶段,利用连续光滑的Sigmoid函数及扩展卡尔曼滤波器改进滑模观测器,减少系统抖振,提高转速稳定性;在转速过渡阶段,设计斜率可调的加权切换函数实现零低速与中高速控制方法的平滑切换。实验结果表明:所提复合控制策略能够实现PMSM全速域无位置传感器控制,消除转矩脉动,转子转速与位置信息辨识准确,系统动态响应快、稳态性能好。

基于文氏桥振荡器的CCCⅡ带通滤波器

为了得到一个最简单、最经济的电流模式高Q带通滤波器,根据传统的文氏桥振荡器和伴随网络理论,设计了一个电流模式/跨导模式的CCCⅡ带通滤波器。通过调整CCCⅡ的偏置电流,电路的极点频率和品质因数能够被独立地电调谐,当满足IB3=2IB4,电路还能产生正弦振荡。由于电路使用4个CCCⅡ和2个接地电容,因此电路适宜集成。计算机仿真结果表明设计方法正确。