| Summary: | 碩士 === 國立臺灣科技大學 === 電機工程系 === 99 === Global industries have gradually adopted ZigBee networks for power meter supervising system’s implementation(Smart Grid). The motivation is essentially to reach the qualified energy management, and subjected for public users’ transparency. In this study, a new integrated wireless and digital power devices are constructed to be a complete power monitoring system. It consists of three kinds of hardware and software: Power information panel, Power monitoring system on digital power meter, information/network module, and monitoring software, in addition, the information receiving software of digital power supervising center.
The practical experiments for the system are carried on five ZigBee modules, including coordinator, router, and end device. The implementation was placed on the office building of ChungHwa Telecom Corporation, for outdoor and indoor scenarios. On the outdoor scenarios, the modules are implemented with the 120 meters of longest distance record. In indoor part, at the same floor, the communication range covers all the node placements. Through the experiment we analyze the modules’ data communication performance using two metrics that sensitively contributes on power meter data reconstruction: delay and packet loss.
On the delay measurement, while the transmission packets are transmitted between 2 to 5 nodes on the effective distance inside 50 meters, the delay time will rise from the minimum 60 to 80ms to the maximum of 100ms, it presents the linear upward characteristic. Moreover, in the powerful exhibition of the voltage Self-adjustment, the system will arrange the power-rate automatically by the setting 6 seconds to count the packet status, through router and end-device to pull-up and pull down the transmission power rate.
For the packet loss measurement, when two modules are implemented the packet loss rate can be accepted until 50 meters of node’s distance, while using three modules, packet loss rate is acceptable up to 80 meters of modules’ distance. After we increase the number of modules to be four, we found in 100 meters the packets are still can be transmitted without loss, and 120 meter for five modules as well. It indicates that in the real implementation, this distance between modules is good enough for secure environment in household and working field implementation.
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