赵良辰_论文最终版8.doc

毕业设计( 论文) 题目背靠背变换器的仿真研究专业电气工程及其自动化班级电气 082 学生赵良辰指导教师李洁 2012 年赵良辰:背靠背变换器的仿真研究背靠背变换器的仿真研究专业:电气工程及其自动化班级:电气 0 82班作者: 指导教师: 职称: 副教授答辩日期: 20 12 -06- 25 摘要背靠背电压源型变换器在轻型直流输电系统, 变速恒频风力发电系统轻型直流输电系统以及电动机变频调速中有着越来越重要的作用。 PW M 整流-PWM 逆变形式的背靠背 VSC 不仅具有良好的输出性能, 更具有良好的输入性能,可获得任意功率因数的正弦输入电流,且具有能量双向流动的良好能力。介绍了背靠背电压源型变流器在 dq 同步旋转坐标系下的动态数学模型、背靠背电压源型变流器与两端交流系统互联时的功率交换控制原理。设计了基于直接电流控制的双闭环控制器,实现了有功功率和无功功率的解耦控制,基于系统传递函数,采用极点配置的 PI 参数设计方法,使控制器的期望性能指标与 PI 参数之间建立了直接的量化关系。最后,利用 PSCAD 软件搭建了背靠背 VSC 变换器控制仿真模型,最终通过对背靠背 VSC 与两端交流系统的功率交换进行控制仿真, 验证了所设计控制器的有效性。关键词: 背靠背电压源型变换器、 dq 轴解耦控制、直接电流控制西安理工大学本科生毕业设计(论文) Abstract Back-to-back voltage source converter is ing more and more important in new fields such as VSCF wind power generator system and HVDC light. back-to-back VSC in the form of PWM rectifi er -PWM inverter not only has good output performance, but also has good input performance , and it can obtain sinusoidal input current with any power factor as well asa bidirectional energy flow . The dynamic mathematical model for back-to-back VSC under dq synchronous reference frame is represented as well as the power exchange control principle between converters and two side ac systems .tA dual closed loop controller based on direct current control strategy is designed for active power and reactive power exchange between the converter and two side ac systems, active power control and reactive power control are decoupled. According to the system transfer function, the direct quantitative relationship is established between the desired performance targets and PI parameters based on pole-assignment for PI parameter ′s design metho d. Finally, power exchange control simulation model for back-to-back VSC based on PSCAD is set up, Power exchange control between back-to-back VSC and two side ac systems is simulated, the validity of the proposed controller is demonstrated by the simulation results. Keywords: back-to-back voltage source converter, dq axis decoupled control, direct current contro l 西安理工大学本科生毕业设计