Research on acceleration phenomena with test equipment of simulating puffer type gas circuit breaker
The diagnosis was investigated by using the acceleration measurement for mechanical failure and degradation of a SF6 gas circuit breaker (GCB). The mechanical model GCB was fabricated to produce similar acceleration characteristics to a real GCB. The MEMS (Micro Electro-Mechanical System) sensor was adopted for the purpose of confirming its applicability with the well-established piezoelectric accelerometer. The acceleration characteristics of the model GCB was generally similar to the real GCB of 300kV class, except the high frequency component. The MEMS sensor application was feasible with some limitations. It was indicated a mechanical failure could be detected by the acceleration measurement.
University research approach to switchgear technology////Arc quenching phenomena
As a university feels lack of possibility for the circuit breaker research, several approaches are described. Four technical fields are explained, and they are 1) arc quenching phenomenon, 2) circuit switching phenomenon, 3) MEMS sensor application technology and 4) new material application technology. Two examples are shown from the field 1). The electron density measurement by a Shack-Harmann sensor is promising to make quenching phenomena clear, as the electron density can be measured at 1 A. The dc circuit breaker research by using a EDLC capacitor bank will be useful for a new electric power grid development.
A Study on Greenhouse Automatic Control System Based on Wireless Sensor Network
The system proposed in this paper collects temperature of leaves and humidity on leaves of crop. As well as greenhouse environmental information such as temperature, humidity, etc. Crop diseases, especially, have deep relationship not only with indoor environmental factors but also with humidity lasting time on leaves and temperature of leaves. Accordingly, monitoring crop itself is as important as monitoring indoor environments. Using these collected greenhouse environmental data, indoor environments can be more effectively controlled, and monitoring crop itself can contribute to improve productivity and to prevent crops from damages by blight and harmful insects. In addition, it will be possible for farmers to do control plant growth through closely studying relationship between indoor environmental information and monitored information on crop itself. Collected data can be stored to database either in server installed in greenhouse or to remote server. It is made possible to collect information and control effectively and automatically greenhouse in the site or from a remote place through web browser. System components are: temperature sensor, humidity sensor, leaf temperature sensor, leaf humidity sensor, Zigbee based wireless sensor node, relay nodes for automatic control, and data server to store greenhouse information. The system is implemented using low power wireless components, and easy to install.