Research On Wireless Network Communication In Measuring Dissipation Factor

In electric power system, capacitive devices are one of the most important ones.They occupy about40%-50%of all the devices, and they always breakdown. If thesedevices fail, it can definitely affect the operation of the substation, and can even causecasualties. So it is necessary to monitor the insulation of these devices, and found thehidden problems in time to prevent accidents. For capacitive devices, the dissipationfactor is one of the most important content of the insulation monitoring.In the beginning, people had to outrage power supply to measure the dissipationfactor. With the development of power system toward to ultra-high voltage, hugecapacity and big system, this monitoring method is obviously not suited to modernrequirements, so the online monitoring technology came into being. Traditional onlinemonitoring methods require a large number of cables laying in the field, and it’s anutterly waste of labor, material and financial resources. This paper applies WSN todissipation factor monitoring, so as to eliminate the cable laying work, which greatlysimplifies the installation process. Through wireless nodes arranged in the field, therewill be a wireless network covering the entire field, and any devices, who complywith this network protocol, can join in the wireless network to transmit. Becausewireless medium don’t need regular maintenance frequently as the wired media dose,it can evidently reduce costs and improve economic efficiency.This paper based on the essence of IEEE802.15.4protocols and WSN, tailor thedesign of a comprehensive set of application layer communication protocol for thedissipation measurement. Through comparing variety of wireless protocols, a suitableone is selected, that is IEEE802.15.4protocol. And then some schemes on wirelesscommunication is compared. On the basis of IEEE802.15.4, formulate the flow ofcommunication of the network protocols and wireless packet format, making devicesformatting network and communication to each other, and allowing dynamic setting of some parameters of the network. This can not only ensure a stable and reliable datatransmission, but also discover and report errors in the network in time. As to UART,communication baud rate is determined through experimental methods. UART packetformat is also explained in detail. This work doesn’t follow traditional method ofMSP430MCU with a wireless transceiver, but use a new TI MCU CC2530, makingthe precision of synchronous trigger basically within±125ns.Considering the project specific implementation, this work designs a complete setof wireless communication system, which has comprehensive design thinking. Andnow has running in some220KV substation in Changchun region. Throughcomparing the measure data of voltage and current to its exact value, it has beenshown that this measurement and communication is accurate and stable, and it canfully competent the task monitoring the dissipation factor in substation.