A 1.6-kW, 110-kHz DC-DC converter optimized for IGBT's

A full bridge DC-DC power converter using a zero current and zero-voltage switching technique is described. This circuit utilizes the characteristics of the IGBT to achieve power and frequency combinations that are much higher than previously reported for this device. Experimental results are included for a 1.6 kW, 110 kHz converter with 95% efficiency     

A 2-kW 100-kHz power converter

The literature contains many papers on resonant switching power converters and their main drawbacks, such as the variable driving frequency. In this paper, we show another approach to the design of switched converters that takes its origin from the high-power converters based on thyristors. It is well known that thyristors are switched off at “zero current” by firing a current oscillation with an auxiliary circuit. These converters work at fixed frequency driven with the pulsewidth modulation technique. We have replaced thyristors with faster devices like insulated gate bipolar transistors and have reused the same ideas at high frequencies (100 kHz), showing that good performance and efficiency can be easily obtained     

Phase-staggering control of a series-resonant DC-DC converter withparalleled power modules

A method of decreasing the ripple on the output voltage of high-power AC-DC or DC-DC series-resonant converters without increasing the internal converter frequency or the capacity of the energy storage elements is discussed. This improvement is accomplished by subdividing the converter into two or more series-resonant power modules operated with a constant relative phase shift (phase-staggering control). The method of eliminating the harmonic components in the input and output currents of the conversion system, without increasing the internal pulse frequency, is justified by Fourier analysis of the current waveforms. The frequency spectra of the source and output waveforms for the continuous and discontinuous resonant current mode are shifted to higher frequency ranges, as computations show for both one single module and multiple paralleled modules. Inadequacies in the phase-staggering control method applied to series-resonant converters are indicated in relation to the dominant harmonic component, in particular for two modules and supported by experimentally acquired waveforms. High-frequency current components to the source and to the load are reduced. Resulting in smaller input and output filters. This improves the resolution of the control of the flow of energy from the source to the load, resulting in a faster system response     

A 2.5-kW cascaded Schwarz converter for 20-kHz power distribution

The cascaded Schwarz converter, which provides a relatively simple method for driving 20 kHz power systems, is discussed. The cascaded Schwarz is compared with other 20 kHz converters, showing that the circuit is relatively easy to protect and provides a predictable trapezoidal voltage waveform. Because it avoids the high currents in a parallel loaded capacitor, the cascaded Schwarz should offer better component utilization than converters with sinusoidal output voltages. Operation has been verified on a 2.5 kW circuit that uses input and output voltages in the same range as those anticipated for certain future spacecraft power systems     

混合动力船舶双向DC-DC变换器的研究与设计

针对全桥双向DC-DC变换器Buck和Boost两种模式参数设计要求不同的问题,提出了一种"占空比-变压器-电感"匹配设计法。对全桥双向DC-DC变换器的两种工作模式分别进行建模,设计了闭环控制系统,Buck模式的闭环控制系统保证了动力电池恒压充电;Boost模式的闭环控制系统保证了母线电压恒定。根据混合动力船舶的特点设计了双向DCDC变换器,仿真实验验证了所设计的双向DC-DC变换器控制系统和控制策略的正确性,保证了分别处于两种工作模式时输出端电压稳定。     

DSP-based active power filter with predictive current control

This paper presents an active power filter based on a digital signal processing (DSP) controller with enhanced current control performance. A novel predictive current control method is introduced to compensate the phase error of harmonic components caused by discrete sampling and finite nonnegligible execution time delay. The concept of average current control is also introduced that is adequate for digital current control. With a close coordination between the reference current prediction, PWM pattern generation, and control timing, a high performance control is achieved. Experimental results show that the developed system gives satisfactory performance in harmonic and reactive power compensation     

A planar 4.5-GHz DC-DC power converter

In this paper, we present two DC-DC converters that operate at a microwave frequency. The first converter consists of a class-E switched-mode microwave amplifier, which performs the DC-AC conversion, and two half-wave diode rectifier outputs. The class-E MESFET amplifier has a minimum power-added efficiency of 86%, corresponding drain efficiency of 95%, and 120 mW of output power at 4.5 GHz. The diode rectifier has a maximum conversion efficiency of 98% and an overall efficiency of 83%. The second converter consists of a high-efficiency class-E oscillator and a diode rectifier. The class-E oscillator has a maximum efficiency of 57% and maximum output power of 725 mW. The DC-DC converter is planar and compact, with no magnetic components, and with a maximum overall DC-DC conversion efficiency of 64% for a DC input of 3 V, and the output voltage across a 87-Ω load of 2.15 V     

A bidirectional DC-DC converter topology for low power application

This paper presents a bidirectional DC-DC converter for use in low power applications. The proposed topology is based on a half-bridge on the primary and a current-fed push-pull on the secondary side of a high frequency isolation transformer. Achieving bidirectional flow of power using the same power components provides a simple, efficient and galvanically isolated topology that is specially attractive for use in battery charge/discharge circuits in DC UPS. The DC mains (provided by the AC mains), when presented, powers the down stream load converters and the bidirectional converter which essentially operates in the buck mode to charge the battery to a nominal value of 48 V. On failure of the DC mains (derived from the AC mains), the converter operation is comparable to that of a boost and the battery regulates the bus voltage and thereby provides power to the downstream converters. Small signal and steady state analyses are presented for this specific application. The design of a laboratory prototype is included. Experimental results from the prototype, under different operating conditions, validate and evaluate the proposed topology. An efficiency of 86.6% is achieved in the battery charging mode and 90% when the battery provides load power. The converter exhibits good transient response under load variations and switchover from one mode of operation to another     

扰动分离自抗扰控制在光电稳定平台上的应用

针对当前光电稳定平台伺服系统中扰动抑制能力不足的问题,提出一种扰动分离自抗扰控制（DSADRC）算法。扰动分离自抗扰控制充分利用工程实际中可获取到的部分已知的光电稳定平台模型信息及经典控制中的控制器信息,并将其加入到自抗扰控制的设计中。该算法通过减少光电稳定平台系统中的总扰动量,增加系统的扰动观测精度及扰动抑制能力。同时,通过算法设计实现了经典控制器的复用,减少了设计工作量。仿真实验结果表明:在控制器相同、扰动条件相同的情况下,扰动分离自抗扰控制阶跃响应调节时间减少58.8%,上升时间减少26.5%,且无超调量;在1V2Hz等效扰动下,系统稳态精度提高51.5%,系统性能提升效果明显。在实物验证实验中,对于不同频率的等效扰动,相比PID控制,扰动分离自抗扰控制稳态精度提升50%以上,有效地提高了光电稳定平台的稳态精度。     

基于自抗扰控制器的柴油机转速控制

当柴油机作为转速控制系统的被控对象时,是一个多变量强耦合非线性系统,采用经典PID控制难以得到满意的控制效果,但是自抗扰控制理论设计的控制器,能够提高调速系统的精度、准确度和柴油机的抗扰动能力。本文主要介绍了自抗扰控制技术(Active Disturbance Rejection Control Technique,ADRC),并且根据自抗扰控制技术设计了切实可行的自抗扰控制器,通过与PID控制的仿真比较,显示出自抗扰控制器对转速控制的较小超调量和较短调节时间,反应出良好的动态性能和稳态特性。     

Data-driven iterative tuning based active disturbance rejection control for piezoelectric nano-positioners

The nano scale motions of piezoelectric actuated nano-positioning systems are very sensitive to operating tasks, external disturbances, as well as variations of system dynamics. In this paper, a data-driven Iterative Feedback Tuning (IFT) based Active Disturbance Rejection Control (ADRC) approach is developed to optimize the control performance by conducting controller parameter tuning iteratively from experimental test data. In particular, a parameterized input-output form of the linear ADRC controller is derived for the nano-positioner, where the IFT algorithm is applied to solve the established optimization problem to get the optimal control parameters. The proposed method is verified in simulations where the selection of control criterion and the impact of update step-size are also discussed. Single-axis and dual-axes real-time experiments are finally conducted on an X-Y piezoelectric actuated nano-positioner, which demonstrate significant performance improvement on nano-positioning and tracking over the conventional ADRC method.     

MPPT控制器的线性自抗扰控制

光伏并网发电系统极易受到外部环境的影响,并且抗干扰能力较差。环境改变、电网不稳定或参数难以确定等原因都会对电能输出效率和其工作效率造成很大影响。针对光伏系统的这些特性,提出一种线性自抗扰控制器对电流进行控制。采用扩张状态观测器对扰动进行补偿,从而快速消除扰动,达到平和状态,使系统对扰动有着很好的适应能力。为了验证该算法的有效性,通过Matlab/Simulink仿真表明,加入自抗扰控制器能够明显提高光伏并网系统的跟踪速度和控制性能,降低了功率震荡,在外界环境突变的情况下,也能够达到很好的效果。     

Fast maximum power point control of current-fed DC-DC converter forphotovoltaic arrays

The design and operation of a modular current-fed DC-DC converter is described, together with the implementation of an algorithm for tracking the maximum power point of a photovoltaic array. The method utilises inherent features of the array current to obtain a fast control action. A novel test setup for the converter system has been developed, and test results are presented which show correct operation of the system with a response time of only a few milliseconds     

基于自抗扰控制的空间飞行器姿态控制研究

空间飞行器姿态控制的主流方法是基于经典控制理论的,但它要求建立对象精确的数学模型。当对象模型不精确或是具有非线性、时变特性时,经典控制方法将很难满足实际的设计要求。在分析了空间飞行器姿态运动特性的基础上,引入自抗扰技术,设计了两种姿态控制系统,并将两者的结果进行对比,验证了自抗扰控制方法的有效性,同时指出了在实际应用中需注意的问题。     

A PWM plus phase-shift control bidirectional DC-DC converter

A pulse-width modulation (PWM) plus phase-shift control bidirectional dc-dc converter is proposed. In this converter, PWM control and phase-shift control are combined to reduce current stress and conduction losses, and to expand ZVS range. The operation principle and analysis of the converter are explained, and ZVS condition is derived. A prototype of PWM plus phase-shift bidirectional dc-dc converter is built to verify the analysis.     

双向全桥DC-DC变换器的优化控制研究与实现

双向全桥DC-DC变换器是固态变压器的重要组成部分,双向全桥DC-DC变换器采用移相的控制方式,但简单的单移相控制方式下存在较大的回流功率,根据相关文献里提到的双重移相控制原理分析内移相占空比与传输功率和回流功率的关系。针对减小甚至消除回流功率这一目标,对内移相占空比进行优化计算。最后搭建实验样机,将单移相控制和优化控制进行实验对比,实验结果证实该优化方法正确性和可行性,具有一定应用价值。     

机载光电稳瞄平台的线性自抗扰控制

为了提高机载光电稳瞄平台的抗扰动能力和动态响应特性,在平台上进行了基于线性自抗扰控制的改进控制方法研究。改进的线性自抗扰控制器采用模型辅助的降阶线性扩张状态观测器以及采用系统输出量和输出量微分来产生控制量,不仅可以减小观测器的相位滞后和观测负担,提高观测器对扰动的估计能力,还可以减小观测器滞后和估计误差对控制律的影响。仿真实验结果表明:改进的线性自抗扰控制器在低中频段具有更好的频域特性,阶跃响应实验中表现出更好的动态响应特性,在系统输入为零的条件下,给系统施加幅值为、频率为2.5 Hz的正弦波力矩扰动和正弦波角速度扰动,基于线性自抗扰控制器的系统输出残差峰值分别为0.175（）/s与0.566（）/s,基于改进的线性自抗扰控制器的系统输出残差峰值分别为0.155（）/s与0.030（）/s,实验结果验证了改进方法的有效性。     

Novel topologies for DC-DC converter with PWM control

Two topologies for the buck converter are presented. The first converter consists of two active switches whereas the second converter, derived from the parent twoswitch converter, consists of only one active switch. The main feature of this new converter is the ability to operate at a constant switching frequency using a simple PWM control. The design of the gate circuit is simplified as there is only one switch. The converter has a good efficiency, as is proved by the experimental results. The operation of the parent two-switch converter, from which the new single-switch converter is derived, is also presented to gain insight into the design of the new converter.     

A 1-MHz hard-switched silicon carbide DC-DC converter

Silicon Carbide (SiC) is a wide bandgap semiconductor material that offers performance improvements over Si for power semiconductors with accompanying benefits for power electronics applications that use these semiconductors. The wide bandgap of SiC results in higher junction forward voltage drops, so SiC is best suited for majority carrier devices such as field effect transistors (FETs) and Schottky diodes. The wide bandgap of SiC results in it having a high breakdown electric field, which in turn results in lower resistivity and narrower drift regions in power devices. This dramatically lowers the resistance of the drift region and means that SiC devices with substantially less area than their corresponding Si devices can be used. The lower device area reduces the capacitance of the devices enabling higher frequency operation. Here, the results from a 1-MHz hard-switched dc-dc converter employing SiC JFETs and Schottky diodes will be presented. This converter was designed to convert 270Vdc to 42Vdc such as may be needed in future electric cars. The results provide the performance obtained at 1MHz and demonstrate the feasibility of a hard-switched dc-dc converter operating at this frequency.     

双有源桥双向DC-DC变换器的多模式控制

双有源桥(Dual Active Bridge,DAB)双向DC-DC变换器能够双向传输功率,实现零电压开关(ZVS),且功率密度高,能够很好地应用到电力自动化设备中。文中详细介绍了DAB变换器的三种常见的控制方式,分别是移相控制、单PWM和双PWM控制。针对变换器存在低载运行时环路电流大、零电压开关范围受限制的缺点,提出一种多模式控制,拓宽了零电压开关的范围,降低了电流的有效值和峰值,使变换器效率提高。最后用MATLAB软件进行仿真,验证了方案的可行性。