【作者】 刘景芳；

【导师】 高强；

【作者基本信息】 哈尔滨工业大学 ， 电气工程， 2011， 硕士

【摘要】 作为柔性交流输电系统中一种重要的无功补偿装置,STATCOM由于具有能够迅速地提供系统动态电压支撑、维持母线电压稳定、补偿系统中的无功功率、降低系统中的损耗、提高经济效益、有效抑制电压波动和闪变、改善系统三相电压不平衡等作用,不仅在输电领域,而且在化工、煤炭等工业应用场合都获得了广泛应用。目前,级联式结构被认为是中压系统STATCOM装置性价比较高的拓扑结构,因此,研制STATCOM装置,使其获得更广泛的应用,具有重要的意义。本文首先对基于H桥级联结构的STATCOM装置工作原理进行了分析,并分别对其调制策略和控制算法进行了数学建模和仿真验证。调制策略采用调制波反相的单级倍频CPS-SPWM调制,使等效开关频率提高;控制算法交流侧则采用状态反馈解耦控制,以期实现电流的完全解耦;直流侧则采用分层控制,上层将电容电压控制为固定值,下层则采用有功矢量叠加的算法来分别控制。在Matlab环境下对该调制策略和控制算法的响应速度、无功补偿效果、直流侧电容电压维持平衡能力进行仿真验证。其次,对级联式STATCOM中功率单元进行了分析设计。结合该功率单元要实现的具体功能,对包括IGBT的驱动与保护部分、三相输入缺相检测部分、故障监测部分及高输入电压的多路输出开关电源部分在内的硬件电路进行了设计。根据上位机与驱动电路通信要实现强电与弱电间的有效隔离,通信速度要快的要求,选择了光纤通信,并对通信控制进行了软件编写。最后,在硬件调试环境下,对驱动电路各部分功能进行了调试。外部模拟电路应用环境,验证功率单元驱动电路设计是否正确。最后给出了主电路参数的初步计算方法,并选择各参数数值。更多还原

【Abstract】 As one of the important reactive power compensators in Flexible AC Transmission Systems, STATCOM has gain world-wide application not only in the transmission system, but also in the chemical, coal and other industrial applications, for it can provide fast dynamic voltage support, maintain bus-voltage stability, provide reactive power, inhibition voltage fluctuation and flicker effectively, change unbalance of the system,and so on. Cascade structure is considered to be cost-effective topology of high pressure STATCOM .Therefore,it make great senses to develop the STATCOM device and make it more popular.This paper derived from the basic principle of STATCOM based on cascaded H-bridges, of which modulation strategies and control algorithm were mathematical analyzed and simulated. The unipolar dual-frequency carrier phase-shifted PWM with inverting modulation wave were choosen as the modulation strategy,which can double the equivalent switching frequency. When came to control algorithm,state feedback decoupled control algorithm ,which realizing the full decoupling of active and reactive power, were applied to AC side, while DC voltage balancing were layered controlled, in the upper it was fixed with a constant value, and in the lower it was controlled with active voltage vector superposition. Modulation strategy and control algorithm were simulated in Matlab environment, in order to verify the response speed, effect of reactive power compensation, the DC bus voltage balance.Secondly, accomplished the design of power cell in cascaded STATCOM. Combined with the specific functions of the hardware circuit, the circuit that can finish driving and protecting IGBT, three-phase input missing detection, and the multi-output switching power supply with high input-voltage were designed. Communication between PC and the drive circuit should be fast, achieve good electromagnetic isolation, therefore, optical fiber were choosen, and the relative software program were finished.At last, all the functions of the drive circuit are debugged in the hardware debugging environment. Applications environment were simulated to verify the correctness of the power cell design. Also a preliminary calculation of the main parameters are given, and the model parameters were selected.更多还原