A battery-free wireless condition monitoring team

Tag : Battery Generator

The Cap-XX SuperCapacitor complements the micro-generator to powerbattery-free wireless sensor networks. The PMG17 microgenerator converts unused mechanical vibration intouseable electrical energy, which after being stored in a Cap-XXSuperCapacitor, this energy can power wireless sensor nodesindefinitely. The SuperCapacitor stores the energy harvested by the PMG17micro-generator (a low but steady source of between 0.5mW and 50mW)and then delivers the peak power needed to transmit sensorcondition data over wireless networks such as IEEE 802.15.4(Zigbee) and 802.11 (WLAN).

The output of the micro-generator can easily cover the power needsof intermittent radio sensor systems such as Wireless HART, SP-100and Wi-Fi in industrial applications, but its output impedance istoo high to supply the 10s to 100s of milliwatts required by sensornodes during data collection and transmission. The high capacitance and low equivalent series resistance (ESR) ofthe SuperCapacitor provides approximately 1 second of peak power totransmit data. "The micro-generator and SuperCapacitor combination eliminatesbattery reliability issues and time-consuming maintenance, whileenabling significant savings in operational costs and energy use,"said Dr Stephen Roberts, Technical Manager for Perpetuum. Cap-XX vice president of applications engineering, Pierre Marspresented the collaborative paper which was co-authored byPerpetuum senior engineer, John Parker. Mars commented, "Wireless system manufacturers can now easilydesign battery-free systems using this 'fit and forget'self-generating power source".

The Nyhamna gas plant in Norway used the PMG17 and Cap-XXSuperCapacitors to power wireless sensor nodes in its networkduring a field trial, which is now operational. Operating faultlessly despite a wide range of temperatures, thesensors monitor the condition of rotating equipment, the mainculprit in production shutdowns, reporting temperature and overallvibration levels every five minutes.