变电站监测中基于虚拟多天线的无线物联网抗干扰研究

发布时间：2018-05-12 15:09

本文选题：变电站 + 脉冲噪声　；参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：高压输变电设备是电网的重要构成元件,积极引入物联网技术,有助于提升设备监测诊断、运行管理水平,推进智能电网建设。无线监测设备作为物联网的核心部分之一,适用于长期、实时、大规模、自动化的环境监测。针对物联网络在变电站的应用,国内外开展了广泛的研究,但是这些研究都没有考虑变电站中无线物联网设备的电磁兼容性。由开关操作、雷击和故障产生的瞬态电磁干扰信号,含有丰富的高频成分,极易通过空间耦合对二次设备形成干扰。瞬态电磁干扰上升时间极短,主要集中在0~8μs内,持续时间可长达20μs,主频范围覆盖到2.5GHz,会对工作在2.4GHz的物联网监测设备产生同频干扰。通过加屏蔽外壳虽然可以提高无线传感器的抗干扰能力,但是电磁干扰仍然可以通过电磁辐射途径耦合到传感器的天线上导致传输数据丢包。另一方面,物联网无线资源分配方面的研究,必须考虑能量效率和能量使用的优化。由于监测终端的电池容量有限,一旦忽视数据传输中对能量效率的优化,将使得数据传输由于能量枯竭而中断,重要信息无法及时传达,同时,已有论文经初步研究了频谱效率和能量效率之间的内在关联,其研究表明,在考虑实际电路功率损耗的情况下,频谱效率和能量效率不再是简单的单调递减关系,而是随着频谱效率的增加,能量效率呈现先单调递增后单调递减的特性。如果一味追求高频谱效率和高吞吐量,将会带来移动终端能量效率的大幅度下降。无线物联网设备由于受到功耗、价格、体积三方面因素的制约,无法使用基于多天线与复杂数字信号处理的抗同频干扰,由于无线物联网设备节点众多且冗余度高,通过单天线节点间的互相协作可以构成虚拟多天线进行传输。虚拟多天线在发射端通过多天线传输相同的数据,在接收端通过相干合成多径信号来获得分集增益。基于这种思想,本论文结合变电站特殊的业务场景,初步给出了变电站中虚拟多天线物联网系统架构。其次,对变电站中一次设备产生的脉冲噪声特性进行了深入的分析研究,提出了“基于虚拟多天线结合先进编码的抗瞬态电磁干扰技术”,通过MATALB建模脉冲噪声模型和虚拟多天线系统模型,从能效和鲁棒性两个方面,验证了智能电网环境下虚拟多天线物理网技术应用的可行性。
[Abstract]:High voltage transmission and transformation equipment is an important component of power grid. The introduction of Internet of things technology will help to improve equipment monitoring and diagnosis, operation management level, and promote the construction of smart grid. As one of the core parts of the Internet of things, wireless monitoring equipment is suitable for long-term, real-time, large-scale and automatic environmental monitoring. For the application of WLAN in substation, extensive research has been carried out at home and abroad, but the electromagnetic compatibility of wireless IoT devices in substation has not been taken into account in these studies. The transient electromagnetic interference signals produced by switch operation, lightning strike and fault contain rich high frequency components, which can easily interfere with the secondary equipment by spatial coupling. The rise time of transient electromagnetic interference is very short, mainly concentrated in 0 ~ 8 渭 s, the duration can be up to 20 渭 s, and the main frequency range is 2.5 GHz, which will cause the same frequency interference to the IoT monitoring equipment working in 2.4GHz. Although the anti-jamming ability of wireless sensor can be improved by adding shielded shell, electromagnetic interference can still be coupled to the antenna of the sensor by electromagnetic radiation to cause data packet loss. On the other hand, the optimization of energy efficiency and energy use must be considered in the research of wireless resource allocation in the Internet of things. Because of the limited battery capacity of the monitoring terminal, if the optimization of energy efficiency in data transmission is ignored, the data transmission will be interrupted because of energy depletion, and the important information can not be transmitted in time, at the same time, The intrinsic relationship between spectrum efficiency and energy efficiency has been preliminarily studied in this paper. The results show that the spectral efficiency and energy efficiency are no longer a simple monotone decreasing relation when considering the actual circuit power loss. However, with the increase of spectral efficiency, the energy efficiency increases monotonously and then decreases. If pursuing high spectral efficiency and high throughput, the energy efficiency of mobile terminal will be greatly reduced. Due to the restriction of power consumption, price and volume, wireless Internet of things equipment can not be used to resist co-frequency interference based on multi-antenna and complex digital signal processing, because of the large number of nodes and high redundancy of wireless Internet of things equipment. Virtual multiple antennas can be transmitted through the cooperation of single antenna nodes. The virtual multi-antenna transmits the same data through the multi-antenna at the transmitter, and the diversity gain is obtained by the coherent synthesis of the multipath signal at the receiving end. Based on this idea, the architecture of virtual multi-antenna IOT system in substation is presented in this paper. Secondly, the characteristics of impulse noise generated by primary equipment in substation are analyzed and studied deeply, and a novel technology of anti-transient electromagnetic interference based on virtual multi-antenna combined with advanced coding is put forward. By using MATALB to model impulse noise model and virtual multi-antenna system model, the feasibility of using virtual multi-antenna physical network technology in smart grid environment is verified from two aspects of energy efficiency and robustness.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM63;TP391.44;TN929.5

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