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.

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.

Model based current mode control design and experimental validation for a 3φ rectifier under unbalanced grid voltage conditions

This paper addresses the control design and the experimental validation of a current mode control for a three phase voltage source rectifier. The proposed control law is able to fulfill the voltage regulation and the current tracking control objectives despite of unbalanced and distorted grid voltages. The proposed control law consists of two loops, which are referred as inner tracking loop and the outer voltage regulation loop. The inner loop is designed to provide damping to the system, which also includes and adaptive mechanism. The construction of the current reference is based on the positive component detection of thegrid voltage. Therefore, the current produced by the power rectifier is proportional to the fundamental component of the grid voltage, despite of the presence of unbalanced grid voltages. The voltage regulation loop is designed as a proportional-integral controller, which is aimed to regulate the DC output voltage to a desired level. Finally, experimental results are obtained in an experimental prototype of2 kW to evaluate the performance of the proposed controller.

A single-inductor dual-output switching converter with average current mode control

An integrated single-inductor dual-output （SIDO） switching DC-DC converter is presented. The outputs are specified with 1.2 V/400 mA and 1.8 V/200 mA. A decoupling small signal model is proposed to analyze the multi-loop system and to design the on-chip compensators. An average current control mode is introduced with lossless, continuous current detection. The converter has been fabricated in a 0.25μm 2P4M CMOS process. The power efficiency is 86% at a total output power of 840 mW while the output ripples are about 40 mV at an oscillator frequency of 600 kHz.

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.

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.

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.

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.

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.

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.

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。

独立充放时序SIDO开关变换器电流型变频控制技术

单电感双输出(single-inductor dual-output,SIDO)开关变换器工作在共享充放时序下存在电感电流纹波大、输出支路间交叉影响严重以及电路参数宽范围变化下控制电路不能正常工作等问题.为此,提出一种独立充放时序电流型变频控制(current-mode variable frequency control,C-VF)技术.首先,具体描述变换器在连续导电模式(continuous conduction mode,CCM)下的工作原理,并推导主电路开环传递函数;进一步构建闭环小信号模型,推导闭环交叉阻抗,详细分析不同输出电压及负载电流下变换器的交叉影响特性;最后,通过仿真和实验进行验证.研究表明:相较于共享充放时序,独立充放时序C-VF CCM SIDO buck变换器减小了交叉影响,改善了负载瞬态响应性能;当两支路负载电压不等时,减轻某一支路负载可以降低该支路的交叉影响;当两支路输出电压相同但负载不同时,重载支路对轻载支路的交叉影响更小.

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。

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。

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。

改进滑模观测器的电流源逆变器驱动PMSM无位置传感器控制

由于电流源逆变器(CSI)的叠流效应以及前级DC-DC控制的母线电流脉动较大,使得扩展反电动势中含有大量谐波,造成较大的位置误差。针对此问题,该文提出一种改进滑模观测器的电流源逆变器驱动永磁同步电机无传感器控制方法。首先,基于传统滑模观测器,设计复系数滤波器代替传统低通滤波器,实现了对估计反电动势的准确提取,同时也抑制了估计反电动势中的高频抖动和高次谐波。其次,将二阶广义积分器内嵌于锁相环中,用于消除位置误差信号中的低次谐波,提高位置观测准确度。最后,将估算的速度信息反馈回复系数滤波器,实现复系数滤波器的自适应性。实验结果表明,所提方法在不同工况下,能够有效提高估算的转子位置精度,验证了方法的可行性与有效性。