Research On Electromagnetic Compatibility Of Wireless Sensor In Substation

As Smart Grid in China continuously developed,Internet of Things is more and more widely applied in power system.With combination of Internet of Things and Smart Grid,number and type of measuring and control equipment in substation are increasing continuously,while the equipment is placed in the same electromagnetic environment with original primary equipment and secondary equipment.As an important part of the measuring and control equipment,Internet of Things is of vital function for signal collection and transmission,where wireless sensors are applied as basic communication and sensing nodes laid around various electrical equipment in substation.This new situation of electromagnetic compatibility in substation is necessary to be considered more comprehensively.In Smart Grid substation,the increasing voltage level brings more electromagnetic disturbance,while sensitivity to electromagnetic disturbance of equipment of Internet of Things grows because of increasing dependence on computer and electronics techniques.In complex electromagnetic environment in China,there is usual electromagnetic disturbance generated from industry frequency electric and magnetic field,corona,partial discharge and switching operation which may result in malfunction of electronic equipment or even maloperation of relay protection that leads to system failure.These electromagnetic disturbance may potentially influence communication of wireless sensor which may lead to packet loss or even halt.The wireless transmission path is relatively vulnerable to electromagnetic disturbance,and therefore,it is necessary to investigate the source of electromagnetic disturbance and its coupling path by modelling and simulating to evaluate electromagnetic environment.Immunity characteristics of wireless sensor is obtained and method to improve its capacity of resisting disturbance is proposed.Research on electromagnetic compatibility of wireless sensor in substation can improve its anti-disturbance capacity and enhance security and reliability of power system.This dissertation researches on electromagnetic compatibility of wireless sensor in substation,through simulation and plenty of field test and laboratory test combined with several engineer project.The test is performed in an open area test site,a dark room,a high-voltage laboratory and 18 substations.Electromagnetic disturbance radiation test,partial discharge test,flashover test,communication test in different antenna polarization and test on communication block impact of large-size metal frame electrical equipment are carried out.Electromagnetic disturbance of steady state and transient state in different voltage level and different type substations is measured.Immunity analysis model is established through simulation,based on the test results.The influence of electromagnetic disturbance on wireless sensor communication is revealed under different frequency,different intensity,different antenna polarization and different layout position.Therefore,electromagnetic compatibility of wireless sensor in substation is evaluated.Layout strategy and electromagnetic protection method of wireless sensor in substation is proposed to suppress electromagnetic disturbance.This research provides theoretical guarantee,application experience and technique support for wide use of wireless sensor of Internet of Things in substations of Smart Grid.