【作者】 孙运全；

【导师】 孙玉坤；

【作者基本信息】 江苏大学 ， 农业电气化与自动化， 2008， 博士

【摘要】 静止同步补偿器（STATCOM）是FACTS家族的重要装置成员之一,在世界各地正得到越来越广泛的应用。因为先进的控制性能,STATCOM已经成为世界上静止无功补偿发展研究的方向。作为STATCOM的重要组成部分,控制器和控制系统直接影响它的运行性能。本文针对混合型级联多电平主电路,结合其控制器和控制系统的设计和研究,对控制器和控制系统的软、硬件设计进行了系统性分析并加以实现。首先,在分析了STATCOM装置的工作原理和工作特性的基础上,给出了STATCOM控制系统的两层模型,即系统层与装置层,它的优点是可以将一个复杂系统分为两个设计相对容易的子系统,并且每个子系统有各自的控制对象,同时各子系统之间还存在着一定的控制关系。分析了STATCOM控制系统模型中由于参数不确定性带来了STATCOM模型的不确定性和摄动性,影响了模型的精确性。随着装置容量变得越来越大以及对输出波形谐波频谱更高的要求,多电平STATCOM主电路成为未来的发展方向。在分析多电平STATCOM主电路结构和原理的基础上,对单元级联式多电平主电路的构成和工作原理进行了研究,而混合型级联多电平主电路与输出相同电平的其它类型多电平主电路相比,具有所需的功率器件最少的优点。采用SHE PWM技术,降低了主电路输出注入系统电流中的低次谐波含量,分析了开关角误差与谐波之间的关系,并给出了通过选择开关角鲁棒系数来降低其影响的方法。其次,在分析了STATCOM系统存在非线性、参数摄动和外部扰动的基础上,建立了存在参数摄动和外部扰动的两种模型,即单机无穷大系统的系统级数学模型与装置级数学模型。采用H₂/H_∞混合控制理论和直接反馈线性方法,分别设计了两种模型的非线性控制器。利用线性矩阵不等式（LMI）对控制器进行求解。通过Matlab仿真,表明了H₂/H_∞混合控制兼有鲁棒性能和最优性能,可使系统快速平息振荡,有效提高系统的暂态稳定,改善系统的动态性能,提高系统的传输容量,同时又能满足故障切除后电压精度的要求。所设计的控制器在保证控制性能的基础上,对参数的不确定具有鲁棒性,同时保证在所有参数摄动范围内具有渐近稳定性。接着,分析了传统集中控制中存在的局限性,依照建立的数学模型,针对混合型级联多电平主电路的特点,在STATCOM控制系统设计中提出了基于模块化嵌入式的分布式控制系统结构,即基本控制单元执行层、协调层和组织层。在这种控制系统结构下,系统具有很好的自适应性,当外界环境变化或出现故障时,通过同级子系统之间以及子系统和较高层次系统之间的信息交换,相关层次的子系统的结构与功能进行调整,从而实现了整个系统的动态平衡,因此整个系统反应灵活,柔性好,可靠性高。采用标准化组件和标准化通讯接口规范,各层之间可以通过明确的接口进行交互,因此不需要关心层内结构的细节。各个组件一般实现不同的功能范畴,要求功能相对独立,组件之间耦合为松耦合。这样可以实现所谓的“即插即用”功能,并使得控制软件的调试、维护和升级都得到简化。随后,在硬件设计方面,详细地设计了基本控制单元执行层和协调层。根据基本控制单元执行层的功能要求,设计了模块化嵌入式单相控制单元。该单元采用基于ARM内核的32位LPC2129局部控制器和CPLD设计方案,完成了对基本控制单元执行层的触发电路、驱动单元、通信单元、同步电路及保护等电路单元的设计。根据协调层的功能要求,采用双DSP方案,设计了模块化嵌入式主控制器单元。DSP56F807（1）完成采集、判断及控制策略等功能,而DSP56F807（2）则负责整个系统的运行、协调及人机交互等功能。同时,还对STATCOM保护进行了初步讨论,提出了主电路故障检测方案,给出了控制性保护是STATCOM装置中一种特殊而且有效的保护,并且具体说明了控制性保护在STATCOM中的实现方法。最后,结合硬件平台和STATCOM的两种运行方式,对STATCOM控制系统的软件进行了设计。利用uC/OS-Ⅱ嵌入式实时多任务操作系统,提高了系统软件的移植性、维护性和扩展性。更多还原

【Abstract】 As one of the important members of FACTS,Static Synchronous Compensator（STATCOM） has widely applied all over the world.Because STATCOM has advanced control performance,it has become the direction of development research in the world’s SVC.As the important components of STATCOM,controller and control system directly impact on the operation performance of STATCOM.Aiming at the mixed-cascade multi-level main circuit and with the design and research of its controller and control system,this paper carries out and achieves system analysis in relation to controller and the control system hardware and software design.At first,the principle and performance of STATCOM are introduced in this thesis.Control system of STATCOM is a two-layer model,the system layer and the equipment layer.Its advantage is that a complex system can be divided into two designed relative easy subsystems, and each subsystem has not only its own control object but also a certain relationship between the various subsystems.In the control system model of STATCOM,parameter uncertainty not only brings uncertainty and perturbation of the STATCOM model but also impacts on the accuracy of the model.As equipment capacity becomes bigger and bigger,and then requirements of output waveform harmonic spectrum become higher,main circuit of the multi-level STATCOM becomes the direction of development in the future.Based on the main circuit structure and principle of STATCOM,the structure and principle of unit cascade multi-level main circuit are studied,and mixed-cascade multi-level main circuit compared with multi-level main circuit of other types of output same level has a advantage of the least needed power devices.Using SHE PWM technology lowers the low harmonic content of the main circuit output injection system current,analyzes the relationship between Switch angle error and harmonic and gives a method reducing its influence through the select switch angle robust coefficient.Secondly,based on nonlinear,parameter perturbation and external disturbance,STATCOM establishes two models existing parameter perturbation and external disturbance,system-level mathematical model and device-level mathematical model of the single infinite system.Using H₂/H_∞Mixed Control theory and direct feedback linear method,the two models are designed for the non-linear controller.Using LMI（LMI）for Solving the controller,through Matlab simulation,it shows the H₂/H_∞Mixed Control both robust performance and optimal performance, rapidly subsides oscillation of the system,effectively improves transient stability of the system, improves dynamic performance of the system,increases transmission capacity of the system and can satisfy the requirement of voltage precision after failure removal.The designed controller based on control performance has robust on uncertain parameters and has asymptotic stability within the perturbation range of all parameters.Then,analyzing the limitations of the traditional centralized control,according to the established mathematical model in this thesis,with the characteristics of the mixed-cascade multi-level main circuit,the distributed control system structure of modular embedded is presented in the control system design of STATCOM,namely,the basic control unit implementation layer,the coordination layer and the organizing layer.In this control system,the system has a good adaptability,when the external environment change or failure,through information exchange in the same level subsystems,as well as between subsystem and higher level subsystem,and the adjustment of the structure and function between the relevant level subsystems,thus the dynamic balance of the whole system is realized,so the whole system has response flexible,good flexibility and high reliability.At the same time,using standardized components and standardized communication interface specifications and interaction between the layers through the clear interface,there is no need of concern within the internal layer structure details.Generally,various components achieve different functional areas to function relatively independent,and the coupling of various components is loosely coupled.This realizes the so-called "plug-and-play" feature,and makes the control software debugging,maintaining and upgrading simplify.Subsequently,in hardware design,the basic control unit implementation layer and coordination layer are designed in detail.According to the functional requirements of the basic control unit implementation layer,the modular embedded single-phase control unit is introduced. Based on the ARM core of the 32 bits LPC2129 local controller and the CPLD design scheme, this unit completes the circuit unit design of the basic control unit implementation layer,such as trigger circuit,drive unit,communication unit,synchronization circuit and protection,and so on. According to the functional requirements of the coordination layer,using a dual-DSP project,the modular embedded main controller unit is designed.DSP56FS07（1）completes some functions, such as,acquisition,estimation and control strategy,and so on,while DSP56FS07（2）is responsible for the operation of the whole system,coordination and human-computer interaction.At the same time,the protection of STATCOM is discussed preliminarily.The main circuit fault detection schemes are presented.The controlled protection is a special and effective protection in STATCOM devices.The implementation method of the controlled protection is explained concretely in STATCOM.Finally,combining the hardware platform with two operation modes of STATCOM,the software of the STATCOM control system is designed.Using uC/OS-Ⅱembedded real-time multi-tasking operating system improves the transplantation,maintainability and scalability of the system software.更多还原