非平衡输入状态下矩阵式变换器的双电压控制策略与仿真

本文分析了当输入不对称或不平衡时,矩阵式变换器的双电压瞬时值控制的原理和在该控制策略下输出电压的合成规律,证明该控制策略具有良好的抗干扰性能;并分析了在非平衡状态下,输入电流的畸变及其消谐方法.最后搭建了与实际电路相近的仿真模型,通过仿真分析,验证了理论分析的正确性,为矩阵式变换器进一步应用研究提供了参考.     

宽输入全桥Buck-Boost变换器控制策略研究

针对全桥Buck-Boost(FBBB)变换器在宽输入电压范围内高散热需求、低效率、可靠性差等问题,提出了一种宽输入FBBB变换器多模式控制策略。该策略根据输入电压与输出电压的关系确定变换器的工作模式,采用平均电流控制与双沿调制、移相控制相结合的方式,实现FBBB变换器在降压、升压和升降压模式之间平滑过渡,变换器工作在有效占空比区间,对电感电流进行有效控制,确保变换器安全可靠工作。使用Type-Ⅲ型补偿网络来改善控制环路,实现高精度输出和快速动态响应。最后通过搭建仿真模型,验证了其正确性和有效性。     

矩阵式变换器的双电压控制策略及其仿真

讨论了基于双电压瞬时值控制的矩阵变换器的开关状态及控制函数, 并在源开关的理论基础上推导出开关状态控制函数表, 最后通过仿真分析, 给出了电压、电流的波形, 验证了理论分析的正确性, 为矩阵式变换器的软硬件设计和实现提供了理论基础.     

矿用超宽输入电压范围电源设计

针对现有多输入电压等级的矿用隔爆兼本质安全型电源存在电压波动大、体积大、维护困难等问题,提出了一种矿用超宽输入电压范围电源设计方案。该电源采用Buck拓扑与反激拓扑相结合的设计,可将AC80~900V超宽输入电压转换为稳定的直流电压。试验结果表明,该电源抗输入波动能力强,输出电压稳定,纹波小,效率高。     

宽输入DC-DC Boost变换器电感参数设计

根据DC-DC Boost变换器的工作原理,给出电流连续模式时电感临界参数的计算表达式。分析负载和开关频率恒定时,临界电感量与占空比的变化关系。重点研究宽范围输入时,电流连续模式下电感量的选取方法。通过仿真进行分析,结果与理论分析一致,验证了电感参数选取的合理性。     

一种应用于LDO的宽范围稳压电路

在LDO的设计中,为了提高输入电源电压上限,一般采用大尺寸的晶体管,但这样会增加电路的面积。为了解决这个问题,采用改进的威尔逊电流镜结构设计了一种宽范围稳压电路,为LDO各个子模块提供电源和偏置。仿真结果表明,稳压电路可以将3.5 V～6 V外部供电电源电压转换为1.8 V内部电压,使得LDO核心电路在高输入电源电压下依然可以使用0.18μm的MOS管,降低了芯片面积,并且可以给LDO模拟模块的设计带来便利。     

一种宽输入范围8 bit循环TDC

设计了一种适用于时域ADC的基于电容-比较器型TDA的循环TDC。循环TDC重复使用单增益级可降低量化时间差量器件的匹配需求,可克服传统延时线TDC中大量延时线变换引起的时间不确定性。同时,循环结构只占用较小的芯片面积而更加适用于片上系统。循环TDC采用不加校准的电容-比较器型TDA来增加线性输入范围,TDA以小于2%的增益误差来放大时间差量。通过0.18μm标准CMOS工艺完成了电路设计和仿真,在1.3 MS/s的采样速率下,TDC获得了±20 ns输入范围和8 bit的分辨率,INL和DNL分别是-1.671/+1.59 LSB和-0.5/+0.604 LSB。     

Multi-input single-output control for extending the operating range: Generalized split range control using the baton strategy

Split range control is used to extend the steady-state operating range for a single output (controlled variable) by using multiple inputs (manipulated variables). The standard implementation of split range control uses a single controller with a split range block, but this approach has limitations when it comes to tuning. In this paper, we introduce a generalized split range control structure that overcomes these limitations by using multiple independent controllers with the same setpoint. Undesired switching between the controllers is avoided by using a baton strategy where only one controller is active at a time. As an alternative solution we consider model predictive control (MPC), but it requires a detailed dynamic model and does not allow for using only one input at a time.     

新能源汽车LLC谐振DC/DC仿真设计

二十一世纪是信息飞速发展的时代,能源技术是世界发展的核心。随着世界能源的过度消耗,世界各国都在发展新能源技术,新能源汽车作为其代表得到了迅速发展,而蓄电池及充放电技术是限制新能源汽车的核心技术之一,对新能源汽车的国内外发展现状及以后的发展趋势进行了分析,指出了双谐振式DC/DC变换器研究的热门问题。采用双谐振式DC/DC变换器作为本次设计变换器的拓扑结构,根据设计要求确定了双谐振式DC/DC变换器的基本参数,使用仿真软件MATLAB/Simulink建立了谐振式DC/DC变换器的仿真模型,用数字控制来达到对谐振式DC/DC变换器的控制,分析其正反向的工作波形,证明了双向谐振式DC/DC变换器的使用在汽车的有效性和可行性,它可以简化电动汽车的控制结构,提高整车的运行效率。     

Type-2 fuzzy control for a flexible-joint robot using voltage control strategy

Type-1 fuzzy sets cannot fully handle the uncertainties. To overcome the problem, type-2 fuzzy sets have been proposed. The novelty of this paper is using interval type-2 fuzzy logic controller (IT2FLC) to control a flexible-joint robot with voltage control strategy. In order to take into account the whole robotic system including the dynamics of actuators and the robot manipulator, the voltages of motors are used as inputs of the system. To highlight the capabilities of the control system, a flexible joint robot which is highly nonlinear, heavily coupled and uncertain is used. In addition, to improve the control performance, the parameters of the primary membership functions of IT2FLC are optimized using particle swarm optimization (PSO). A comparative study between the proposed IT2FLC and type-1 fuzzy logic controller (T1FLC) is presented to better assess their respective performance in presence of external disturbance and unmodelled dynamics. Stability analysis is presented and the effectiveness of the proposed control approach is demonstrated by simulations using a two-link flexible-joint robot driven by permanent magnet direct current motors. Simulation results show the superiority of the IT2FLC over the T1FLC in terms of accuracy, robustness and interpretability.     

A new wide range Euclidean distance circuit for neural network hardware implementations

In this paper, we describe an analog very large-scale integration (VLSI) implementation of a wide range Euclidean distance computation circuit - the key element of many synapse circuits. This circuit is essentially a wide-range absolute value circuit that is designed to be as small as possible (80 /spl times/ 76 /spl mu/m) in order to achieve maximum synapse density while maintaining a wide range of operation (0.5 to 4.5 V) and low power consumption (less than 200 /spl mu/W). The circuit has been fabricated in 1.5-/spl mu/m technology through MOSIS. We present simulated and experimental results of the circuit, and compare these results. Ultimately, this circuit is intended for use as part of a high-density hardware implementation of a self-organizing map (SOM). We describe how this circuit can be used as part of the SOM and how the SOM is going to be used as part of a larger bio-inspired vision system based on the octopus visual system.     

矿用宽范围直流输入电源模块设计

针对矿用传感器与直流供电系统电源电压等级不一致、电源类型不相符的问题,提出了一种新型宽范围直流输入的本安型电源模块设计方案。该电源模块基于Buck和隔离反激拓扑设计,前端采用Buck电路避免了直接采用反激拓扑而导致开关管承受高耐压所带来的风险,后端采用隔离反激拓扑满足了非本安端和本安端的电气隔离要求,具有输入防反接、DC9~350V范围直流输入、本安电源输出、易于集成的优点。     

A new control strategy for IKN-type coolers

This paper presents a new system for the optimized control of IKN-type cement coolers based on adaptive predictive methodology. The new system introduces the concepts of ’layer on grate’ and ’thickness of slope’, which allow a decoupled multivariable control of the layer of clinker over the grate, and the flow rate of the cooler fans, solving a fundamental control problem for this type of process and maximizing the heat transfer from the cooling process to the kiln. The experimental results obtained in the Gador mill of Holcim, in Almeria (Spain), are analyzed.     

基于矩阵式变换器的异步电机直接转矩控制策略

研究一种基于矩阵式变换器的异步电机控制策略,分析了异步电机的直接转矩控制方法和矩阵式变换器的空间矢量调制,给出了在直接转矩控制方案中,矩阵式变换器矢量电压的选择.这一控制策略同时实现了矩阵式变换器的空间矢量调制和异步电机的直接转矩控制.利用MATLAB仿真平台实现了该控制策略,仿真结果表明:采用这一控制策略的调速系统具有良好的静、动态性能,并且保持了单位功率因素.     

A precise robust fuzzy control of robots using voltage control strategy

Fuzzy control of robot manipulators with a decentralized structure is facing a serious challenge. The state-space model of a robotic system including the robot manipulator and motors is in non-companion form, multivariable, highly nonlinear, and heavily coupled with a variable input gain matrix. Considering the problem, causes and solutions, we use voltage control strategy and convergence analysis to design a novel precise robust fuzzy control (PRFC) approach for electrically driven robot manipulators. The proposed fuzzy controller is Mamdani type and has a decentralized structure with guaranteed stability. In order to obtain a precise response, we regulate a fuzzy rule which governs the origin of the tracking space. The proposed design is verified by stability analysis. Simulations illustrate the superiority of the PRFC over a proprotional derivative like (PD-like) fuzzy controller applied on a selective compliant assembly robot arm (SCARA) driven by permanent magnet DC motors.     

A new repetitive control for LTI systems with input delay

In this paper, a new form of Repetitive Control (RC) is proposed which is applicable to an extended class of systems, including time-delay systems. A new convergence condition which is necessary and sufficient will be derived for this RC. Simulation examples will illustrate the practical applications of the results to process control problems.     

A new digital control strategy for a nuclear boiling water reactor

A method is proposed for the design of constant gain optimal feedback control laws for discrete-time systems which reduce trajectory sensitivity to small system parameter variations and ensure the closed-loop eigenvalues at the prescribed locations. The selected performance index is of standard linear regulator type, modified to include a quadratic sensitivity term. An efficient computational procedure based on direct cost oprimization using gradient type algorithm is also reported. A case study of a Boiling Water Reactor power plant has been presented to illustrate the application of the design procedure.     

A new impulse detection and filtering method for removal of wide range impulse noises

A new impulse detection and filtering algorithm is proposed for restoration of images that are highly corrupted by impulse noise. It is based on the minimum absolute value of four convolutions obtained by one-dimensional Laplacian operators. The proposed algorithm can effectively remove the impulse noise with a wide range of noise density and produce better results in terms of the qualitative and quantitative measures of the images even at noise density as high as 90%. Extensive simulations show that the proposed algorithm provides better performance than many of the existing switching median filters in terms of noise suppression and detail preservation.     

An MRAS method for sensorless control of induction motor over a wide speed range

This paper addresses the problem of wide speed range sensorless control of induction motor.The proposed method is based on model reference adaptive system (MRAS),in which the current model serves as the adjustable model,and a novel hybrid model integrating the modified voltage model (MVM) and high-frequency signal injection method (HFSIM) are established to serve as the reference model.The HFSIM works together with MVM to improve the performance of the rotor speed and rotor flux position estimation at low speed,whereas at high speed,the MVM acts alone.In addition,a rotor resistance online estimation scheme is proposed to update the rotor resistance contained in the adjustable model and to ensure the estimation accuracy further.Experimental results show that the proposed MRAS method is very effective from low to high speed range,including zero speed.