浙大电力电子系统建模及控制ch1_dc-dc变换器的动态模型

2020世纪人类最伟大的项科技成果世纪人类最伟大的项科技成果 1. Electrification1. Electrification 2. Automobile2. Automobile 3. Airplane3. Airplane 4. Water Supply and Distribution4. Water Supply and Distribution 5. Electronics5. Electronics 6. Radio and Television6. Radio and Television 7. Agricultural Mechanization7. Agricultural Mechanization 8. Computers8. Computers 9. Telephone9. Telephone 10. Air Conditioning10. Air Conditioning and Refrigerationand Refrigeration 11. Highways 12. Spacecraft 13. Internet 14. Imaging 15. Household Appliances 16. Health Technologies 17. Petroleum and Petrochemical Technologies 18. Laser and Fiber Optics 19. Nuclear Technologies 20. High-performance Materials 受到电力电子技术的深刻影响受到电力电子技术的深刻影响 电力电子装置的分类 （有功）电源：直流开关电源、逆变电源、不停电电源（UPS）、直 流输电装置等 无功电源：静止无功补偿装置（SVC）、静止无功发生装置（SVG）、 有源电力滤波器、动态电压恢复装置（DVR）等 传动装置：直流调速装置、各类电机的变频调速装置等。 电力电子装置的应用范围十分广泛，粗略可分为： （有功）电源 无功电源 传动装置 电力电子技术发展 两条主线两条主线 半导体功率器件的发展 从结型控制器件（晶闸管、功率GTR、GTO）到场控器件（MOSFET、IGBT、IGCT） 的发展历程 高频化、低功耗、场控化成为功率器件发展主要特征 功率器件发展历程也是向理想电子开关逐步逼近的过程 功率变换电路的发展：电路拓扑结构逐渐走向稳定 器件和电路的日趋成熟，注意力转向电力电子装置的整体性能的优化问 题，电力电子系统的问题比以往更加受到重视。 电力电子系统问题 控制系统动态性能、稳态的性能 并联系统的控制问题：均流、输出纹波抑制技术 组合或接连系统的分析与控制 功率管理控制（效率的提高技术） 热分析和设计 电力电子装置对电能质量影响和改进 电磁兼容分析和设计 SOC,SOP功率集成 系统级功率集成：硬件电路的标准化网络控制技术 电力电子装置的技术指标 电力电子装置需要满足静态指标和动态指标要求。 如直流开关电源指标：电源调整率、负载调整率、输出电压的精度、纹波、动态性能、 变换效率、功率密度、并联模块的不均流度、功率因数和EMC。 影响技术指标因素：功率电路设计，系统控制的设计 功率电路设计：电路拓扑、磁设计、热设计、功率元件驱动 功率电路设计影响的指标：变换效率、功率密度、纹波等技术 系统控制的设计影响的指标：电源调整率、负载调整率、输出电压的精度、动态性能、 并联模块的不均流度等指标 功率电路设计功率电路设计与与系统控制的设计系统控制的设计就如汽车的左、右轮，同等重要就如汽车的左、右轮，同等重要 通讯基础电源的系统 为了达到所需的静态和动态指标，一般需要引入反馈控制。 电力电子系统中包含功率开关器件或二极管等非线性元件，是非线性系统 AC/DC DC/DC Objective: maintain v(t) equal to an accurate, and constant value V. There are disturbances due to input vg(t) load R There are uncertainties in component values DC/DC converter system Objective of modeling the converter 1. Design a compensator for the converter system to have good characteristics in both static and dynamics 2. Stability analysis 3. Building a simulation model to evaluate a converter system How to model the converter or inverter is the goal of this course ? 1. Modeling of CCM DC/DC converter 2. Modeling of DCM DC/DC converter 3. Modeling of DC/DC converter with current peak control 4. Compensation design for DC/DC converter system 5. Modeling of single phase inverter 6. Modeling of Three phase inverter or converter Contents Chapter 1 Modeling of CCM DC/DC converter 1. Develop tools for modeling of CCM DC/DC converter systems 2. How do AC variations in vg(t), R, or d(t) affect the output voltage v(t)? 3. What are the small-signal transfer functions of the converter? Purpose of this chapter Capture dominant behavior and ignore insignificant phenomena Simplified model yields physical insight, allowing engineer to design system to operate in specified manner Modeling Definition: describing dynamic physical behavior by mathematical means For modeling, simplifications are used due to following reasons: DC/DC converter system( static state) )(td)(tvDtd)(t t PWM调制器G(s)refv( )gv t补偿网络电压参 考值( ) t驱动器R+-( )v tLCv ( ) tvcdTs Tsttvc(t)constDtd)(ssf2Switch frequency D and Dm are constants, | Dm | Ts is zero. Equilibrium (dc) state-space averaged model 0 = A X + B U Y = C X + E U A = D A1 + D' A2 B = D B1 + D' B2 C = D C1 + D' C2 E = D E1 + D' E2 Solution for X and Y: where Averaged state space equations Large signal dynamical model Nonlinear model Perturbation and linearization Substitute into averaged state equations: Perturbation and linearization Linearized small-signal state equations Use DC equations: 0 = A X + B U, Y = C X + E U The second-order (nonlinear) terms are smaller State-space averaged small signal AC model Circuit Averaging and Averaged Switch Modeling Above methods are mathematical intensive Rather than doing mathematical operations, is it possible to derive the model by performing the converter circuit transformation. Separate switch network from remainder of converter nonlinear linear Linear subcircuit Nonlinear switch network Boost converter example Original circuit is divide into linear subcircuit and switch network 1. Simple dc-dc converter case, the switch network is two terminal network 2. The switch network terminal variables are terminal voltages and currents: v1(t), i1(t), v2(t), and i2(t). 3. Two of these terminal vraibales are taken as independent inputs to the switch network, and the remaining two variables are then viewed as dependent outputs of the switch network. 4. Definition of the switch network terminal variables is not unique. Discussion Two ways to define the switch network Boost converter example Since i1(t) and v2(t) coincide with the converter inductor current and output voltage and are state variables, it is convenient to define these waveforms as the independent inputs to the switch network. v1(t) and i2(t) are selected as dependent outputs. )(2ti)(1ti)(1tv)(2tv+ _ _ + Obtainin