Page 66 - From Smart Grid to Internet of Energy

52 From smart grid to internet of energy

ZigBee Pro, WirelessHART, Wireless network for Industrial Automation – Pro-
cess Automation (WIA-PA), and ISA100.11a have gradually decreased costs
and leveraged widespread use of WSNs in industrial automation, residential
applications, and related remote monitoring applications. The main parts of a
WSN are comprised by power management module, the sensor, a microcontrol-
ler for data processing, and a wireless transceiver. The sustainability of sensors
along WSN is ensured by power management module that is mostly desired to
be capable for energy harvesting by solar, kinetic or thermal energy sources.
The sensors are responsible for acquiring analog or physical signals such as irra-
diation, vibrations, pressure, humidity or electrical signals and to transform
them into electrical signals to be processed by microprocessor. Then the micro-
controller processes inherited signals to generate transmission signals such as
modulated waveforms and additional recording or data storage applications
may be realized at this stage. The modulated waveforms are supplied to trans-
ceiver module that is a wireless RF transmitter and receiver in one module.
Thus, communication interface is obtained and wireless transmission medium
is used to communicate with nearest sensor node or management node [41].
The organization and transmission process of WSNs is shown in Fig. 1.16
where the sensor nodes firstly communicate with each other by deploying their
status and receiving others. Afterwards, sensors are organized into a networks
structure as selecting one of star, mesh, linear or tree topologies and then data
transmission paths are calculated to transmit data over suitable routes. The
transmission distance of WSNs are relatively shorter around 1000 m since
the power of sensors is generally provided by batteries. The sensor networks
are operated in multihop networks that is achieved by using sensors in

FIG. 1.16 Organization and transmission of WSNs.