Читать книгу Smart Grid and Enabling Technologies - Frede Blaabjerg - Страница 31

The communication system connects various components of SG architecture for real‐time control, monitoring, and data utilization. Integrated communication is the connector for all SG technologies. The communication infrastructure of the SG is predicated upon three types of networks: Home Area Network (HAN), Neighborhood Area Network (NAN), and Wide Area Network (WAN). Figure 1.10 shows the diagram of the SG communication infrastructure [28]. HAN is installed and operated in a small area (tens of meters) and has a lower transmission data rate of hundreds of bits per second. HAN consists of a broadband internet connection used to communicate and share the data between devices over a network connection and smart meters. HAN offers more efficient home energy management [28]. NAN is installed and operated in an area over hundreds of meters. A number of HANs can be connected to one NAN to transmit the data of other NAN networks and to local data centers for storage and further analytics. The NAN has a 2 Kbps transmission data rate. Different technologies can be used to implement the NAN network such as PLC, Wi‐Fi, and Cellular [29].

WAN is installed and operated in an area of tens of kilometers and it contains several NANs and LDCs. The communication between SG components such as renewable energy generation, transmission, distribution, and the operator control center are predicated upon a WAN network [30]. SG communication infrastructures share the same main challenge, which is how to be merged effectively. A number of technologies can be employed to the SG to achieve an effective merge between communication infrastructure. These technologies are ZigBee, WLAN, Cellular networks, and Power Line Communication (PLC).

ZigBee is utilized in applications requiring a small data rate, prolonged battery life, low price, and safe networking. Applications also include wireless light switches, traffic control systems, meters for in‐home‐displays, and extra consumer and industrial devices that require a short‐range of wireless data transmission at relatively low rates. The benefits of ZigBee application in the SG are low cost, decreased size, and relatively decreased bandwidth. The drawbacks of the ZigBee are the small battery which suggests a short lifetime, small memory, limited data rate, and low processing capability [31].

Figure 1.10 Schematic diagram communication infrastructure for the SG.

WLAN is a wireless local area network (WLAN) that links two or more devices through the use of spread‐spectrum or Orthogonal Frequency Division Multiplexing (OFDM) [32] and generally delivering a connection through an access point to the internet. This provides customers with the chance to roam around in a local coverage area and at the same time maintain connection with the network. The benefits of WLAN are low price, huge installations worldwide, and plug and play (PnP) devices. The main drawback of WLAN is possible interferences with other devices that communicate on similar frequencies.

Cellular networks are vastly employed in the majority of countries and possess a well‐recognized infrastructure. Cellular networks could be utilized for communication among a number of components and devices in the SG. There are a number of current technologies for cellular communication including GSM, GPRS, 3G, 4G, 5G, and WiMAX [33]. The benefits of the cellular networks are presently available infrastructure across a vast area of implementation, elevated rates of data transmission, existing security systems implemented in cellular communication. The main drawback is that cellular networks are shared with other customers and are not fully devoted to SG communications.