| High voltage power transmission equipment is an important component of power grid.Introducing the Internet of things technology to power grid can help to enhance the equipment monitoring and diagnosis,operation and management level,and promote the construction of smart grid.As one of the core part of the Internet of things,wireless monitoring equipment is suitable for long-term,real-time,large-scale,automated environmental monitoring.For the application of the Internet of things to substation,a wide range of research has been carried out at home and abroad,but these studies have not considered the electromagnetic compatibility of the wireless networking equipment in substation.Due to the transient electromagnetic interference signal generated by switch operation,lightning stroke and malfunction has rich high frequency components,which is easy to be disturbed by the spatial coupling of the two devices.Transient electromagnetic interference has a very short rise time,mainly concentrated in 0 ~ 8μs,lasts up to 20μs,the frequency,which covers to 2.5GHz,will cause co-channel interference to the network monitoring equipment working on 2.4GHz.Although the shielding shell can improve the anti-interference ability of wireless sensors,electromagnetic interference can still be coupled to the antenna through the electromagnetic radiation path,which leads to the transmission data packet loss and delay.On the other hand,the research on wireless resource allocation of Internet of things must consider the optimization of energy efficiency and energy usage.Due to the limited battery capacity of the monitoring terminal,if ignoring the optimization of energy efficiency,the data transmission will be interrupted for the energy depletion,the important information cannot be communicated timely.At the same time,there are some papers study the internal correlation between spectrum efficiency and energy efficiency.The research shows that,under considering the actual circuit power loss,spectrum efficiency and energy efficiency is no longer a simple monotone relationship,but with the increase of spectral efficiency,energy efficiency increasing firstly and then decreasing monotonically.If blindly pursuing high frequency spectrum efficiency and throughput,it will bring a large decline on the energy efficiency of the mobile terminal.Due to the power consumption,price and volume constraints,wireless networking equipment cannot use anti-cochannel interference technology based on multi antenna and complex digital signal processing.Wireless networking equipment usually has many nodes and high redundancy degree,so it can form a virtual antenna to transmit through cooperation among nodes.The virtual multi antenna transmits the same data through multiple antennas at the transmitting end,and the diversity gain is obtained by the coherent combination of the multipath signal at the receiving end.Based on the above idea,this paper presents a virtual multi antenna networking system architecture of substation based on the special operation scenarios in substation.Then,the pulse noise characteristics of primary equipment of substation are analyzed and studied deeply.Anti-transient electromagnetic interference technology based on virtual multi-antenna and advanced encoding,the impulsive noise model and a virtual multi antenna system model are established through MATLAB.From the two aspects of energy efficiency and robustness,this paper verifies the application feasibility of antenna physical network under mart grid environment. |
