Page 141 - From Smart Grid to Internet of Energy

Power line communication technologies in smart grids Chapter 4 125

harmonized standard or a special procedure that should be approved by an inde-
pendent notified body. The IEEE P1901.2 specification can be given as a special
procedure example [30]. In the United States, the FCC regulates PLC emissions
within 9–490 kHz frequency band through the Code of Federal Regulations,
Title 47, Part 15 (47 CFR §15) where the PLC systems are divided into two sub-
group as “power line carrier systems” and “carrier current systems”. The second
subgroup aims to create a connection among distribution substations and cus-
tomers for enabling smart grid applications. Out-of-band conducted emissions
limits and in-band radiated emission limits are described in §15.107(c) and
§15.209(a) paragraphs, respectively [31]. In Japan, Standard T84 of the ARIB
authorizes the use of 10–450 kHz frequency band for the NB PLC systems. In-
band and out-of-band conducted emission limits are also defined with the mea-
surement procedures. Even though the EMC regulations of China for the NB
PLC systems are not accessible, it is reported that there are several PLC devices
working below 95 kHz or up to 422 kHz [30].
The LDR NB PLC systems are compatible with several recommendations
such as ISO/IEC 14908-3 (LonWorks), ISO/IEC 14543-3-5 (KNX), CEA-
600.31 (CEBus), IEC 61334-3-1, IEC 61334-5 (FSK and Spread-FSK) and
so forth. In addition, there are some non-Standards Developing Organizations
(SDOs) based examples for LDR NB PLC systems such as Insteon, X10, Home-
Plug C&C, SITRED, Ariane Controls, BacNet. Pico Electronics developed X10
standard in 1975, which is an international protocol for communication between
electronic devices employed in home automation. It uses low-voltage power
lines for signaling and control operations. Digital data are transmitted by using
120 kHz carrier at the zero crossings of the AC signal and one-bit data is con-
veyed at each zero crossing. Following the X10, KNX and LonWorks are devel-
oped for several physical communication media such as twisted pair, power
lines, infrared and Ethernet. LonWorks devices are able to work in one of
two different frequencies based on the application type. While the
CENELEC-A band is utilized for electric utility applications, the
CENELEC-C band is exploited for commercial, in-home and industrial appli-
cations. Depending on the used frequency band, data rates are in the level of few
Kbps. KNX is standardized through EN 50090 and ISO/IEC 14543-3-5 [32]
while LonWorks is standardized by ISO/IEC 14908-3 [33, 34]. The most com-
mon PLC technologies used today that employ FSK or Spread-FSK are speci-
fied in the IEC 61334 (especially in IEC 61334-5-1 and IEC 61334-5-2).
On the other hand, HDR NB PLC systems operating in the CENELEC, FCC
and ARIB bands are based on multicarrier technologies such as OFDM, and can
present higher data rates typically up to 500 Kbps. When compared to the LDR
systems, the HDR NB PLC systems are more appropriate for SG applications
such as smart metering, remote control, and energy management. ITU-T G.
hnem and IEEE 1901.2 are important standards of HDR NB PLC systems while
PRIME and G3-PLC are non-SDO-based examples. It is important to note that
several coexistence mechanisms have been developed to ensure interoperability