UPS逆变器数字控制研究

UPS逆变器的数字控制是实现全数字控制UPS的关键。本文对数字PID控制进行研究。针对数字PID控制方法输出性能不够理想的问题,提出了准双环控制,并采用了死区补偿和输出电流补偿。实验结果表明死区补偿和输出电流补偿的有效性以及整个控制策略的可行性。对无差拍控制方法进行研究,针对无差拍控制对系统参数变化的鲁棒性问题,提出了一种新的控制方案——渐近收敛无差拍控制。该方案与传统无差拍控制的区别是,不是将正弦信号作为参考电压,而是采用当前的输出电压和正弦信号的加权平均作为下一控制周期的目标量。理论分析和实验结果表明,渐近收敛无差拍控制有良好的稳态性能和快速的动态响应,对系统参数的变化有较好的鲁棒性。     

基于重复控制和无差拍控制的逆变电源数字控制技术研究

随着DSP技术的发展，数字控制在逆变电源控制领域的应用受到人们的关注。逆变电源中因非线性负载等因素引起的干扰具有周期性，而这些干扰导致输出波形的畸变具有重复性，采用重复控制策略可以消除输出电压谐波，但该控制方法的动态响应慢。无差拍控制具有瞬时响应快，精度高等特点。文中将重复控制和无差拍控制相结合用于逆变电源数字控制系统中，得到更为完善的逆变电源控制策略。仿真结果表明，由该方法设计的控制器用于逆变电源系统具有输出波形好，动态响应快，适应负载的能力强等优点。     

带状态观测器无差拍控制技术在单相UPS中的应用

将带状态观测器的无差拍控制技术应用于不间断电源（UPS）的控制中,仿真和实验结果表明带状态观测器的无差拍控制技术能有效改善UPS系统的动态特性。     

数字PID控制器简述

数字PID控制器包含硬件和软件两部分，数字控制最重要的就是算法问题，本文简略介绍PID控制原理和算法。     

基于电流无差拍控制的级联型SVG研究

将级联型变流器应用于无功补偿装置是实现大容量无功补偿的重要途径。文中介绍了级联型静止无功发生器的基本原理和结构,讨论了适用于级联型逆变器的基于瞬时无功理论的新型指令电流计算和无差拍电流跟踪控制工作原理,用无差拍电流控制取代传统PI控制应用在级联型静止无功发生器中,解决了PI控制数学模型复杂,参数难以确定的问题。最终通过Matlab仿真验证设计可行性。     

一种基于TMS320F2808的高精度UPS电源锁相技术

针对全数字控制的UPS系统,结合锁相环原理,提出了一种基于DSP TMS320F2808的高精度数字锁相控制方案。建立了数字锁相环的模型,列出了相应的算法和程序实现流程,理论上锁相精度可高达0.144°。在实验板上仿真并最终在实际的UPS样机上进行了实验,实验及实际测试结果充分验证了该方案的正确性和可行性。     

基于DSP实现的无差拍控制逆变器

介绍了一种通过状态的数字瞬时反馈,利用微处理器的高速数据计算功能实现逆变器的全数字化控制的无差拍算法以及利用PI的最新DSP（TMS320F240）实现无关拍控制的方法及控制流程,仿真和实验表明,它具有瞬时响应快、精度高、THD小等特点。     

基于DSP无差拍控制的逆变电源研究

随着高性能数字信号处理器的广泛应用,传统模拟控制的逆变技术被数字化电源取代已成为必然趋势.逆变电源因非线性负载等因素引起的干扰,采用常规控制难以获得理想的控制效果.提出一种基于DSP实现的PI控制和无差拍控制方法相结合的数字双闭环控制方法.逆变器控制电路的电流内环采用优化了的数字PI控制方法;电压外环采用干扰预测型无差拍控制方法.该方案将无差拍控制的瞬时响应快,精度高和PI控制简单,参数易整定,鲁棒性好等优点相结合,能够得到更优的控制效果.最后的仿真试验表明,采用数字双闭环控制方法的逆变器具有输出波形好,响应快和负载适应能力强等优点.     

基于DSP及FPGA的UPS设计

目前,UPS（不间断电源）已被广泛应用到各行各业,人们对UPS的性能也提出了越来越高的要求。文章介绍了基于LF2407A及FPGA的数字在线式UPS的设计,采用DSP芯片满足了UPS逆变器数字控制算法实时性高的要求,并使硬件系统模块化、控制灵活、通讯方便、可靠性高。同时,利用FPGA器件实现键盘扫描及液晶显示接口等,进一步简化了电路设计。     

单相光伏并网逆变器无差拍控制的研究与仿真

光伏并网逆变器是光伏发电系统的主要部件,为了达到更好的效率输出更高质量的电能,对逆变器电流进行快速有效的控制尤为关键。该文简单介绍了当前光伏并网逆变器的几种常用控制方法及其基本思想,分析了并网逆变器的工作原理和无差拍控制方法的原理,给出了逆变器脉冲宽度的计算和参考电流的获取方法,通过MATLAB/Simulink软件仿真表明,无差拍控制在单相光伏并网逆变器控制中动态响应特性好,控制方便,电流跟踪电网电压波形好。     

逆变器无差拍性能控制方案的分析与设计

分析了两种单电压环的无差拍控制方案。通过分析,比较了两者的异同,指出单纯保证输出电压无差拍控制方案的劣势。并详细分析了能够同时实现两个状态无差拍控制的单电压环控制方案。该方案利用输出电压反馈进行极点配置,实现系统对给定无差拍跟踪;利用负载电流进行前馈控制,实现系统对扰动的抑制。并针对控制策略进行了仿真,验证了方案的可行性。     

Digital Control of Three-Phase Series-Parallel Uninterruptible Power Supply Systems

In this paper, a new digital deadbeat controller is designed, implemented, and applied to a three-phase series-parallel line-interactive uninterruptible power supply (UPS). This kind of UPS system provides input power factor correction, output voltage conditioning, and high efficiency. The objective of the controller is to achieve deadbeat dynamic response for the parallel and series converters. The proposed controller adjusts the current of the parallel converter and voltage of the series converter with two and four sampling periods, respectively. A reduced-parts topology is also introduced that has less number of power electronics components as well as switching functions. The power flow of the system in the presence of current and voltage harmonics is discussed. Simulation and experimental results are presented, which show the viability of the proposed controller for this topology.     

Disturbance observer based fully digital controlled PWM inverterfor CVCF operation

A new approach for digital feedback control of a PWM inverter is proposed, in which an output DB (deadbeat) control is achieved combined with a disturbance observer. In the proposed scheme, the pole placements of the state observer and the disturbance observer are chosen separately. When the two observers employed the same pole placements, the experimental setup had a tendency to become unstable due to the detection error. By selection of the different pole placements, the disturbance observer quickly estimates the disturbance and feedforward disturbance cancellation is achieved. Then the state observer estimates the state variables at the next sampling instant, and the deadbeat controller is applied to the nominal system. This scheme has advantages in robustness in the practical application. From the view point of UPS applications, the advantages and disadvantages are discussed through simulations and experiments. Compared with other digital control laws, the superiority of the proposed control law is verified     

Computer-based controller design for quantum boost series resonant rectifier

To obtain a stable output voltage from a recently-developed rectification circuit called a quantum boost series resonant rectifier (QBSRR), two control schemes, digital PI (proportional-integral) control and deadbeat control, are derived for a computer-based system. Since the output voltage regulation loop has a sampling time corresponding to the zero crossing point of the AC line voltage, the output voltage can be controlled regardless of the 120 Hz ripple component. By deriving a simple and exact model for the current program loop (open loop) of a QBSRR and using the pole-assignmenl technique, the controller gains can be systematically designed in the digital PI control scheme. The deadbeat control scheme is also developed to maintain fast dynamic performance in the presence of any load variations. In this control scheme, the controller gain is adjusted in accordance with the load information using a load estimation method. Simulation and experimental results are presented to verify the usefulness of these two control schemes.     

Deadbeat control of PWM inverter with modified pulse patterns foruninterruptible power supply

A modified algorithm of pulse-width-modulation (PWM) inverter deadbeat control suitable for uninterruptible-power-supply (UPS) systems is presented. Two state variables are measured at each sampling interval, then, using the data, the pulse width is computed in real time in order to force the output voltage equal to the reference at each sampling instant which is called the deadbeat control. Two kinds of PWM pulse patterns are used to increase the fundamental component of the output voltage, considering the microprocessor computation time. Experimentation and simulation has verified that the proposed control scheme increased the output-voltage amplitude, providing an excellent transient response and accurate phase positioning for various load conditions. This algorithm is suitable for applications of high-power UPS systems, in which the switching frequency is in the range of a few kHz and the precise control of power flow is required     

DSP control of high-power UPS systems feeding nonlinear loads

Many facilities, such as patient health care centers, data processing systems, and critical telecommunication links, rely on uninterruptible power supplies (UPS) to maintain a continuous supply of power in case of a line outage. In addition to requiring continuous power, many critical nonlinear loads are sensitive to incoming line transients and input harmonic voltage distortion. Conventional UPS systems operate to protect against such disturbances using complex filtering schemes, often employing large passive components. This paper presents the advantages of using real time digital signal processing (DSP) control of UPS systems. A DSP controlled UPS inverter and harmonic conditioning system is described and the performance is verified on a 150 kVA system     

低中频信号采样及数字相检在机载雷达中的应用

分析了Ｉ、Ｑ幅相误差对系统的影响，介绍了低中频采样、数字正交化技术的几种方法，并给出了仿真结果。结合现代机载火控雷达的特点，讨论了其可行性及局限性，提出了两种实现方法     

几种功率因数校正的新方法

介绍了充电泵功率因数校正（PFC）、数字PFC和带PFC的在线UPS的几种新方法。这几种方法不同于传统带PFC控制IC的有源PFC解决方案。