【作者】 张毅；

【导师】 杨晓萍；

【作者基本信息】 西安理工大学 ， 水利水电工程， 2005， 硕士

【摘要】 无功补偿是保持电网高质量运行的主要手段之一。目前广泛应用的静止无功补偿装置中,静止同步补偿器(STATCOM)由于其具有的诸多特点,已成为静止无功补偿技术的主要发展方向之一。 本文在确定了STATCOM主电路形式的前提下,根据其工作原理,和对脉冲发生器的功能要求,设计采用数字信号处理器作为脉冲控制设备。在分析传统空间矢量脉宽调制(SVPWM)方法的控制原理及其应用在三电平或更高电平逆变器电路控制时存在的不足之处的基础上,提出了一种改进的SVPWM控制方案,旨在通过将原三电平空间矢量图向两电平空间矢量图的转化,以及控制量参考电压的相应变换,达到直接应用两电平SVPWM方法进行调制,实现简化算法的目的。针对二极管篏位形式电路固有的中点电位偏移问题,本文也提出了相应的控制策略。此外又以五电平逆变器为例。说明提出的方法可以进一步扩展到多电平逆变器电路控制中。本文采用MATLAB对所提算法进行了仿真,结果证明所设计的改进SVPWM方法可以有效控制逆变器开关器件的动作,解决中点电位不平衡问题。最后,本文对主电路中主要硬件的参数进行了计算、选择,给出了采用TMS320LF2407 DSP芯片实现的脉冲发生器设计方案,它与主控制器的数据交换通过串行外设接口SPI完成,从而实现了无功补偿装置真正意义上的全数字化控制方案。更多还原

【Abstract】 Var compensation is one of dominating methods for keeping power system in condition of favorable running. Now, var compensation devices in wide use are synchronous var compensation equipments combining with power electronic technique. Because of its many advantages, Static Synchronous Compensator has been the main direction of developing synchronous var compensation technique.After the main circuit of STATCOM is decided, this paper utilizes digital signal processor as controlling apparatus according to its working principle and the demands for pulse generator’s function. Through analyzing the controlling principle of conventional space-vector PWM and its disadvantages when used in three-level and multi-level inverter, this dissertation presents an improved SVPWM which can use two-level SVPWM and simplify total algorithm by convertering three-level space vector diagram into two-level space vector diagram as well as transforming reference voltage. Meanwhile, a corresponding strategy is also introduced to solve the inherent neutral point potential fluctuations of diode-clamped circuit. Moreover, this paper proves the utilization of new SVPWM in multi-levelinverter above three with an example of five-level inverter. The MATLAB has been made use of to simulate and the results shows that mentioned method can effectively realize controlling transistors and resolve neutral point unbalance.Finally, the way selecting main elements and designing scheme of pulse generator based on DSP (TMS320F2407) is shown in this dissertation, and the communication between the controller and the pulse generator is achieved with SPI, so the control strategy of total digitization is realized really.更多还原