基于主从结构微电网的控制运行与电能质量改善的研究

发布时间：2019-05-16 16:36

【摘要】：分布式电源以其绿色环保,储量丰富等特点,受到了各方越来越多的关注。随着对微电网研究的深入,微电网的电能质量问题愈加突显。本文从主从结构下微电网的控制策略和电能质量改善措施两个方面展开研究,以提高微电网的电能质量。文章首先总结了微电网技术的研究现状,并对微电网的电能质量问题进行了分析。建立了微电网并网逆变器在abc三相静止坐标系和dq同步旋转坐标系下的数学模型,推导了恒功率控制器和恒频恒压控制器的结构。利用LCL型滤波器作为微电网并网逆变器的输出滤波环节,并对LCL型滤波器的性能进行了详细分析,同时介绍了LCL型滤波器的参数设计方法。在PSCAD仿真软件对上述理论分析进行了仿真验证,仿真结果表明采用上述控制方法和LCL型滤波器,能够实现微电网的稳定运行,减少微电源和并网逆变器对微电网电能质量的影响。其次,本文在总结前人对微电网中的电能质量问题的研究和所提出的改善方案的基础上,采用了一种新型的能够实现微电网对传统大电网并网发电、无功补偿和谐波抑制等多种功能复合的微电源并网逆变器的复合控制方法,并详细推导其工作原理:通过将电网电流的谐波检测信号与恒功率控制下功率环的输出信号进行叠加,并将此复合信号通过电流控制环节和PWM控制环节,实现并网逆变器的多功能运行。并详细分析了并网逆变器复合控制中电网电流谐波检测环节和SVPWM控制环节的现实方法。并在PSCAD中建立仿真模型,对所采用的复合控制方法进行仿真验证,仿真结果验证了所提上述理论分析的正确性。最后,搭建了以TMS320F28335为控制芯片的实验平台,编写系统软件程序,完成系统实验。实验结果表明并网逆变器的新型复合控制方法能够有效抑制电网谐波。
[Abstract]:The distributed power supply is more and more concerned with its green, environment-friendly and rich reserves. With the deep research of the micro-power grid, the electric energy quality problem of the micro-power grid has become more and more prominent. This paper studies the control strategy and power quality improvement measures of the micro-power grid under the master-slave structure, so as to improve the power quality of the micro-power grid. In this paper, the research status of the micro-grid technology is summarized, and the electric energy quality problem of the micro-power grid is analyzed. The mathematical model of the grid-connected inverter of the micro-power grid under the abc three-phase static coordinate system and the dq synchronous rotating coordinate system is established, and the structure of the constant-power controller and the constant-frequency constant-voltage controller is deduced. The LCL-type filter is used as the output filter of the grid-connected inverter of the micro-power grid, and the performance of the LCL-type filter is analyzed in detail, and the parameter design method of the LCL-type filter is also introduced. The simulation results show that the above-mentioned control method and the LCL-type filter can realize the stable operation of the micro-power grid and reduce the influence of the micro-power supply and the grid-connected inverter on the power quality of the micro-power grid. Secondly, on the basis of summarizing the previous research on the electric energy quality problem in the micro-power grid and the proposed improvement scheme, a new type of grid-connected power generation can be realized by using a new type of micro-power grid, The invention discloses a compound control method of a micro-power grid-connected inverter which is combined by a plurality of functions such as reactive power compensation and harmonic suppression, and the working principle thereof is deduced in detail: the harmonic detection signal of the power grid current is superposed with the output signal of the power ring under constant power control, And the multi-functional operation of the grid-connected inverter is realized through the current control link and the PWM control link. In this paper, the real-time method of the power grid current harmonic detection and the SVPWM control link in the compound control of grid-connected inverter is analyzed in detail. And a simulation model is established in the PSCAD, the adopted compound control method is simulated and verified, and the simulation result verifies the correctness of the theoretical analysis. Finally, the experiment platform with TMS320F28335 as the control chip is set up, the system software program is written, and the system experiment is completed. The experimental results show that the new compound control method of the grid-connected inverter can effectively suppress the harmonic of the power grid.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM732

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