三相恒压恒频逆变电源的输出波形重复控制技术

对瞬时控制和重复控制的内模原理进行了分析，提出了基波扰动瞬时反馈控制内模与谐波重复控制内模相结合的控制器。仿真和实验验证了该方案可以保证系统有较快的动态响应，稳压精度高，输出电压谐波畸变率小。     

Linear Phase Lead Compensation Repetitive Control of a CVCF PWM Inverter

This paper presents a simple and efficient linear phase lead compensation repetitive control scheme for engineers to develop high-performance power converter systems. The linear phase lead compensation helps a repetitive controller to achieve faster convergence rate, higher tracking accuracy, and wider stability region. In the proposed scheme, the phase lead compensation repetitive controller is plugged into generic state-feedback-controlled converter systems. Its comprehensive synthesis, which involves principle, analysis, design, modeling, implementation, and experiments, is systematically and completely presented in great detail. A complete series of experiments is successfully carried out to verify the solution.     

Phase compensation second-order repetitive control for CVCF PWM inverters

Phase compensation for high-order repetitive control (HORC) can improve system transient and steady-state performances. The phase compensator is often designed as the inverse transfer function of a closed-loop system. No other phase compensation methods for HORC have been reported up to now. Hence, in this paper, a simple approximate phase cancellation second-order repetitive control (RC) is proposed. The compensator is a linear combination of two different linear phase lead compensators, which can better fit the inverse of a plant model phase curve compared with the conventional linear phase compensator. Optimisation is introduced to design the parameters of the approximate phase cancellation second-order RC. Analysis and design of the second-order repetitive controlled pulse width modulation inverter system are presented. Simulations and experiments are provided to demonstrate the effectiveness of the optimisation method and verify the advantage of the approximate phase cancellation compensator.     

Zero tracking error controller for three-phase CVCF PWM inverter

A zero tracking error control scheme for three-phase CVCF PWM inverters is proposed. The proposed scheme uses repetitive controller (RC) to force output line voltages to track a sinusoidal reference signal with zero error. Minimised voltage distortion and a fast response are obtained. The validity of the proposed scheme has been verified by simulations     

A General PWM Strategy for Four-Switch Three-Phase Inverters

A general pulsewidth modulation (PWM) method for control of four-switch three-phase inverters is presented. The proposed vector PWM offers a simple method to select three or four vectors that effectively synthesize the desired output voltage, even in presence of voltage oscillations across the two dc-link capacitors. The method utilizes the so called space vector modulation, and includes its scalar version. Different vector combinations are compared. The effect of Wye and delta motor winding connections over the pulse width modulator is also considered. The common mode voltage generated by the four-switch three-phase converter is evaluated and compared to that provided by the standard six-switch three-phase inverter. Simulation and experimental results are presented to demonstrate the feasibility of the proposed approach     

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     

Phase-Shifted Carrier PWM Technique for General Cascaded Inverters

Phase-shifted carrier (PSC) pulsewidth modulation (PWM) in its conventional form is a good solution for single-phase Cascaded inverters as alternative phase opposition disposition (APOD) PWM for single-phase diode clamped inverters. PSC distributes the switching angles of APOD PWM waveform among the legs uniformly and reduces the switching frequency of each leg. This paper proposes a modified PSC technique based on partly shifted carriers for all disposition types including phase disposition (PD) which is suitable for three-phase cascaded inverters. Simulation results are also included for using carrier-based space-vector PWM (SVPWM).     

PWM变频器谐波及其抑制策略综述

随着PWM变频器的广泛使用,它所带来的问题不可忽视。本文主要介绍了变频器使用过程中带来的共模电压和过电压问题。分别介绍了共模电压和过电压的产生机理,在此基础上介绍了过电压和共模电压的几种抑制策略,包括抑制过电压的几种滤波器以及共模电压滤波器和PWM调制策略的优化,并对这几种抑制策略进行了分析比较。     

A Novel Three-Phase Reference Sine-Wave Generator for PWM Inverters

A hybrid circuit for producing a three-phase reference sine wave required with PWM inverters is described in this paper. The principle of the circuit is simple and the implementation of the circuit is easy. The circuit has all the features discussed in the literature. The unit built has, apart from the three-phase sine waves, balanced three-phase square and triangular waves. A high-frequency triangular wave already available in the circuit can be used for the PWM control circuitry. The scheme can easily be extended to generate sine waves of any number of phases.     

Microprocessor Control for Two Magnetically Coupled Three-Phase PWM Inverters

The requirements on the control set for two PWM inverters coupled by a three-phase harmonic canceling reactor are described, and its method of operation, based on a microprocessor Intel 8086 is explained. The input information is a reference space vector (rsv), which represents the required motor voltages. It is shown how the six respective inverter-output potentials can be calculated in a very short time based on this reference vector. One free running mode for low frequencies and special pulse sequences which are synchronized with the stator frequency are realized.     

Multicarrier PWM With DC-Link Ripple Feedforward Compensation for Multilevel Inverters

Like most power converter topologies, multilevel inverters are controlled with modulation techniques that are conceptually based on nonlinear waveform synthesis assuming constant dc-link voltages. However, real applications have load and supply dependent dc-links that usually present important low frequency ripple, which is also modulated and transmitted to the load, generating undesirable low frequency voltage and current distortion. This paper introduces a simple but effective dc-link ripple feedforward strategy into traditional carrier-based modulation techniques. The dc-link ripples are measured and used to modify the carriers or the reference directly in the modulation stage. Simulation and experimental results show the accuracy of the proposed method, eliminating low order harmonics in the load current.     

Improved PWM Control Strategy for Inverters and Induction Motor Drives

This paper develops a novel pulse-width modulation (PWM) strategy for application in uninterruptible power supply (UPS) and ac motor drive systems. The voltage/current harmonic spectra and other properties of this PWM scheme are thoroughly investigated. This modulation strategy is compared with other modulation techniques, especially with the commonly used sinusoidal modulation scheme, from the standpoints of simplicity, inverter switching losses, motor losses, and other output performance features. This novel modulation scheme produces an acceptable motor curent waveform while keeping the number of inverter commutations low. Implementation of this scheme is quite simple in hardware-based as well as microprocessor-based systems.     

PWM逆变器PI双环模拟控制技术研究

文章分析了PWM逆变器模拟控制的特点,采用了一种PI双环(输出电压外环电容电流内环)模拟控制方案,利用极点配王的方法设计控制系统参数,通过仿真分析了该控制方案的可行性,最后给出了各种条件下的实验波形。实验结果表明该方案设计简单、实用,能很好地达到逆变器输出的各项性能指标要求。     

实用新型PWM逆变器双环控制技术研究

文章分析了PWM逆变器控制的特点,采用了一种新的双环（瞬时输出电压外环和电容电流内环）控制方法,控制系统参数是利用极点配置的方法设计,设计起来十分简单。在通过仿真论证了该控制方案的可行性之后进行了实验。实验结果表明该方案简单实用,逆变器输出电压波形具有十分优良的动、稳态性能。     

西门子的优化三电平PWM信号生成方法

本文介绍西门子公司使用的优化三电平PWM信号生成方法,它基于三角载波比较法,计算量少,响应快,实现简单,输出谐波小,有直流母线中点电压自平衡能力。其特点是能解决输最窄脉冲限制影响输出电压波形问题,允许开关频率小于500Hz,且每周期开和关的次数不大于1,开关损耗小。     

双馈式风电变流器网侧变换器控制研究

本文介绍了风电变流器网侧PWM变换器的数学模型和控制框图,给出了控制电路的硬件构成和软件流程,并给出实验波形。     

一种电流型PWM控制芯片的设计

设计并实现了一种高性能的功能齐全的电流型PWM控制芯片。电路采用可调整的带隙基准源和电流型反馈模式,具有基准精度高、温漂低、系统动态响应快等优点。电路的输出级驱动电流可达1A,开关频率可达500kHz,具有过压、过流保护和欠压锁定的功能。     

UPS电源逆变环节嵌入式重复控制系统的改进

在基于嵌入式重复控制和传统P控制的复合控制方案的基础上,加入积分控制,应用于110V50Hz UPS的逆变环节,加速了调节过程,改善了系统静态特性。文章详细分析了系统的结构、重要控制参数的整定,并在SABER软件环境下建立50Hz UPS电源的逆变闭环控制系统仿真模型。仿真实验结果表明:采用此控制方案在额定负载范围内输出特性良好,能获得稳定的50Hz正弦电压,是一种高性能、低成本的控制系统。     

A New Analog Controller for Three-Phase Four-Wire Voltage Generation Inverters

This paper introduces a new controller for three-phase four-wire inverters, with the control goal of generating high-quality three-phase output voltages for all sorts of linear/nonlinear and balanced/unbalanced loads. The proposed controller employs a circuit-level decoupling method, and it is implemented by logic circuitry in combination with a control core and a feedback signal processor. Almost all dc–dc control methods can be adapted as the control core, while the feedback signal processor can be implemented by either voltage compensator and/or current compensator. The implementation of the controller is simple and flexible with only logic and analog circuitry needed. Yet, it demonstrated experimentally excellent load handling and source voltage noise rejection ability. The prototype is tested under balanced and unbalanced resistive and nonlinear loads, as well as under extreme load transients. It is also tested with power from a noisy dc input source. In all cases, the prototype demonstrated high-quality output voltages.