【作者】 杨金辉；

【导师】 戴瑜兴；

【作者基本信息】 湖南大学 ， 电路与系统， 2010， 博士

【摘要】 高频全控型电力电子器件和高性能DSP控制器的问世,使PWM逆变系统的数字控制成为当今电力电子技术的热门研究领域。先进控制技术的应用可以提高PWM逆变系统输出电压的稳定性和可靠性,同时改善系统的动稳态等性能,便于系统的优化升级和产品化。PWM逆变系统向着数字化、模块化、网络化、智能化的方向发展,本文针对数字化PWM逆变系统,研究和开发系统控制关键技术,为系统的设计与开发提供理论依据和实现途径。(1)研究了数字化PWM逆变系统的应用领域与发展趋势;从数字化PWM逆变系统的波形控制、脉宽调制与系统控制的角度,深入研究了逆变控制技术的理论基础和技术基础;阐述了项目的研究背景和作者所承担的开发任务。(2)对于数字化单相PWM逆变器,将其主电路分为逆变桥单元和输出滤波单元,分别建立二者的数学模型。逆变桥单元和PWM产生过程等效为一个增益恒定的放大器,建立了输出滤波单元的连续时间、离散时间模型,对LC滤波参数进行了分析设计。对于数字化三相PWM逆变器,分别建立了基于三相静止abc坐标系模型、基于坐标变换αβ坐标系模型和基于同步旋转dq坐标系模型,三相滤波单元可通过坐标变换解耦为两个单相滤波单元,因而单相PWM逆变器的研究方法和结论都可应用于三相PWM逆变器。为便于对逆变系统控制算法进行仿真研究,建立了单相和三相PWM逆变器的Matlab仿真电路模型。(3)针对逆变系统负载适应性能不强、动静态性能不佳的特点,深入研究了几种实用型逆变波形复合控制策略。通过算法理论推导及分析,给出了各种复合控制策略的实现方法并做了相应的仿真研究;对各种策略的特点和特性进行分析和比较。针对逆变系统,提出了一种基于神经网络内模原理的逆变波形控制策略,建立了系统的正模型和神经网络内模控制器,有效的提高了系统的逆变波形质量和负载适应性。(4)从载波调制和空间矢量调制的角度对单相和三相逆变系统的调制技术进行了深入研究。对于单相逆变系统,分析了采样型SPWM技术,给出了一种脉冲二重化数字SPWM技术,在相同载波频率下获得较普通SPWM低两倍谐波的波形。通过引入单相逆变系统“线电压”的概念,实现了单相SVPWM技术,研究结果证明了单相SVPWM与载波PWM的统一性。对于三相逆变系统,将单相脉冲多重化SPWM实现方法推广到三相系统实现三相数字SPWM技术;研究了三相SVPWM技术的原理及实现方法;通过对两电平以及多电平载波PWM和SVPWM两类调制技术的对比研究,证明了三相SVPWM与载波PWM的统一性。研究表明SVPWM通过在载波PWM调制中迭加适当的零序分量实现,SVPWM通过对载波调制信号注入零序信号与载波PWM相统一。(5)针对逆变系统控制与功能实现,重点分析研究了嵌入式实时操作系统μC/OS-II平台下的软件锁相控制算法。以逆变电源为例,实现了μC/OS-II在LF2407A上的移植;对系统进行任务划分和实现调度;推导了基于同步调制和基于异步变频调制的软件锁相控制算法。利用LF2407A微处理器,分别给出了两种软件锁相控制算法的DSP实现方法,解决了旁路/逆变输出切换时对系统和负载的冲击问题和EPS在系统断电情况下快速起动、快速切换的问题。(6)应用数字化PWM逆变系统控制关键技术,研制高性能环保节能型数字化逆变电源系列定型产品,实现数字化升级换代,提高产品的性价比。本文重点针对一款70kW数字化三相EPS新产品的研制工作,从控制关键技术算法的实现思想、核心硬件模块开发、软件系统设计等方面阐述数字化EPS系统的设计创新。数字化逆变系统控制关键技术解决了控制精度、跟踪速度和逆变输出的切换时间、转换效率等核心技术问题,整机技术性能指标到达有关标准要求和预期的设计目标,目前该机型已作为2010年新产品投入市场应用。数字化PWM逆变系统控制关键技术,逆变波形复合控制策略提高了逆变波形质量、系统动静态特性和负载适应性;脉宽调制技术解决了逆变系统逆变控制问题,简化了逆变算法,提高了逆变效率;软件锁相控制算法解决了EPS旁路/逆变输出切换冲击问题以及快速起动/切换的问题。更多还原

【Abstract】 Digital control of PWM (Pulse Width Modulation) inverter system becomes a popular research area in power electronic technology with the appearance of high performance power transistor and DSP controller. The application of cybernetics technology can upgrade the stability of the system’s output voltage, improve the performance of the dynamic and the steady response, also make the products easily standardized and upgraded. To meet the trend of a digital, modulational, network, intellectual PWM inverter system, the dissertation focused on the research of its digital control key technology, and provides theory foundation and realization means for the system’s supply design and development.(1)Digital PWM inverter system’s application field and development trend have been researched. The theory and technique foundation have been deeply researched based on the digital PWM inverter system’s waveform control, inverter control and system control argument. The paper explained the research background of the project and the project tasks undertaken by author.(2)To reserach digital single-phase PWM inverter, the main circuit was separated into inverter model and output filter model, and its mathematical model was built independently. The inverter model was equival to an amplifier. The LC parameters of the output filter model had been analysised and designed. To reserach digital three-phase PWM inverter, the mathematical models based on abc coordinate,αβcoordinate transformation, dqo coordinate transformation were built independently. The three-phase filter can be decoupled to two single-phase filters through coordinate transformations. So it’s easy for three-phase inverter model introducing single-phase inverter study method. The simulation models of the digital single-phase and three-phase PWM inverter systems were found to make the system structure clear and convenient for the system control algorithm design..(3)To solve the problem of the performance and load adaptability of PWM inverter system being not satisfying, this paper researched several practical digital waveform control strategies. Through the controller arithmetic deducing and analysis, the controller realization method was put forward. And through the simulation research, its own characteristic was analyzed and compared to each other. In addition, the paper put forward neural network internal model control theory based on inverter waveform control arithmetic. The algorithm could effectively enhance the system dynamic or static performance and system load adaptability.(4)According to the single-phase inverter and the three-phase inverter, digital inverter control technology was studied on two categories of carrier modulation and space vector modulation. In the category of single-phase inverter, a pulse multiplied digital SPWM technique was put forward. And its waveform spectrum proved that the technique can obtain twice the harmonics frequency than the common SPWM technique can, under the same carrier frequency. Through introducing the concept of single-phase inverter“line voltage”, a single-phase space vector PWM technique was studied and its DSP realization method was put forward. The research proved the equivalence between carrier PWM and space vector PWM in single-phase inverter. In the category of three-phase inverter, the theory of the three-phase carrier PWM and space vector PWM technology were studied and its DSP realization methods were put forward. This paper also further studied and compared the two PWM inverter control algorithms, and proved that they are equivalence in nature. The results proved that space vector PWM is a special kind of carrier PWM, the zero sequence signal is the connection with space vector PWM and carrier PWM.(5)For the inverter system control and function realization, the paper analysised and researched the phase lock algorithm based onμC/OS-II operation system. Take inverter power for example,μC/OS-II operation system was transplanted to microchip LF2407A and the system duty was divided and dispatched. A synchronous modulation algorithm and an asynchronous varying-Frequency modulation algorithm based on the inverter digital phase lock technique were put forward. These arithmetic effectively solved the impact problem of the system and loads in the EPS(Emergency Power Supply) bypass/inverter output switching, and also solved its quick start and fast-switching problem under the city power failure.(6)The digital PWM inverter control key technologies were using to develop power products, realize products promotion and enhance its performance. The paper explained the design innovation of digital EPS system by the control key technology algorithm’s realization, core hardware module’s development and software system’s design of a 70kW digital three-phase EPS’s design and application. The digital PWM inverter sysytem’s control key technologies improved control precision, track speed and solved the EPS quick start and fast-switching problem. The EPS prototype completely met the standard requests and the anticipated design requirements. As 2010’s new product, it has been invested market using. The research and development of digital PWM inverter system control key technology, waveform control strategies enhanced system dynamic and static responding characteristic, inverter waveform quality and load adaptability. Inverter control arithmetic solved inverter power control problem, simplified the control arithmetic and improved inverter efficiency. The phase lock algorithm solved the EPS bypass/inverter output switching impact problem and quick start and fast-switching problem.更多还原