1、 IEEE Standard for Power Line Communication Equipment Electromagnetic Compatibility (EMC) RequirementsTesting and Measurement Methods Sponsored by the Standards Committee IEEE 3 Park Avenue New York, NY 10016-5997 USA 7 January 2011 Sponsored by the Power System Communications Committee of the IEEE
2、Power +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be obtained through the Copyright Clearance Center. Introduction This introduction is not part of IEEE Std 1775-2010, IEEE Standard for Power Line Communication EquipmentElectrom
3、agnetic Compatibility (EMC) RequirementsTesting and Measurement Methods. Power line communication (PLC) technology has developed over a long period of time. As early as 1838 Edward Davy proposed remote electricity supply metering for the purpose of checking the voltage levels of the batteries at unm
4、anned sites in the London-Liverpool telegraph system. The first carrier-current system for mains signaling was established in 1893 by the Swiss Electricity Board. The carrier frequency transmission of voice over power lines began in the 1920s. Due to low attenuation and low noise in the transmission
5、 lines at the carrier frequencies (15 KHz to 500 KHz), a distance of 900 km between transmitter and receiver could be attained with a power of 10 W. In 1930 Ripple Carrier Signaling was implemented in Germany over medium- and low-voltage distribution power lines. Such systems typically operated in t
6、he frequency band 125 Hz to 3000 Hz, so a carrier signal propagated with low losses. Advances in communication technology in the late 1990s led to new research and development activities related to data communication through the power grid. Known widely as power line communications (PLC), this techn
7、ology is also named broadband over power line (BPL), power line telecommunication (PLT), and power line technology (PLT). PLC created a mix of high expectations and concerns mainly due to perceived EMC problems and absence of regulatory and standardization framework to address them. In 2000 several
8、European countries independently proposed EMC regulations for PLC. Later, the Joint Working Group of CENELEC and ETSI started developing a standard covering the EMC aspects of wire-line telecommunications networks including their in-home extension. The standard scope is focusing on the limits and in
9、 situ measurements procedures for EMI measurements. Currently the standard is under development. In 2004 the regulatory uncertainty in the U.S. ended when the FCC approved the Report and Order “Amendment of Part 15 regarding new requirements and measurement guidelines for Access Broadband over Power
10、 Line Systems” (ET Docket No. 04-37). The Amendment: (a) defines the Access and In-House BPL system; (b) contains the emission limits for them; and (c) describes in detail the measurement procedure for emissions measurements from BPL equipment verification and certification. However, immunity requir
11、ements and testing were not covered under this document. In the U.S., narrowband carrier-current systems are regulated by the Federal Communication Commission (FCC) under CFR 47 Part 15 Rules for unintentional radiators. Therefore, for such systems the methods provided by ANSI C63.4 are fully applic
12、able for emissions measurements.aIn 2004 the IEEE published IEEE Std 643-2004 B31 for low-frequency power line communications covering 50 kHz to 450 kHz band operations.bIn 2005 CENELEC published EN 50412-2-1, which is the first immunity standard for PLC equipment. In 2007 the Japanese Ministry of I
13、nterior and Communication (MIC) published “Japanese (radio) Regulations for the Broadband PLC (or PLT or BPL),” which is part of Japanese Radio Law and Ordinance regulating radio equipment. In 2008 CISPR sent out for circulation the Draft Amendment to CISPR 22, which will describe the limits and met
14、hod of measurement of broadband telecommunication equipment over power lines. Both the Japanese and CISPR documents are applicable for In-premises BPL devices. aInformation on references can be found in Clause 2. bThe numbers in brackets correspond to those of the bibliography in Annex G. iv Copyrig
15、ht 2011 IEEE. All rights reserved. The growing concerns from PLC manufacturers and utility operators about the absence of an internationally recognized EMC measurement and testing methodology for PLC equipment and installations was addressed when in 2004 IEEE Standards Association established the PL
16、C EMC Working Group P1775 to develop this standard. The Working Group is co-sponsored by the Power (2) parallel to the ground and parallel to the power line (HY); and (3) perpendicular to the ground (HZ). To establish the measurement values, the loop antenna shall not be rotated to maximize each of
17、the readings; rather, its axis is positioned in only the three orientations described above at each distance and the three separate measurements are combined into one linear RMS value H in A/m at that measurement distance according to: H = (HX2+ HY2+ HZ2)1/29Information on references can be found in
18、 Clause 2. 10NTIA Report 08-450 on broadband over power line systems notes that “the use of the optional 1 meter measurement height coupled with a 5 dB correction factor will, in general, provide similar results to measurements performed using a 1 m to 4 m measurement height.” 14 Copyright 2011 IEEE
19、. All rights reserved. IEEE Std 1775-2010 IEEE Standard for Power Line Communication EquipmentElectromagnetic Compatibility (EMC) RequirementsTesting and Measurement Methods Readings are converted from magnetic field strength in dBA/m where dBA/m = 20log10(A/m) to V in dBV/m by adding 51.5 dB.11See
20、CISPR 16-1-4. When using active magnetic loops, care shall be taken to prevent ambient signals from overloading the spectrum analyzer or antenna pre-amplifier. High ambient signals may create overload, which should be addressed by the use of a band stop or band pass filter. h) Where specified by nat
21、ional regulations the lateral or slant distance in the regulation between the EUT and measurement antennas shall be used. In the absence of the regulation, where feasible a lateral distance of 10 m (33 ft) shall be used. i) Where measurements at 10 m (33 ft) lateral distance are not feasible, measur
22、ed data shall be scaled to the reference distance by a distance correction factor according to national regulations or, in their absence, calculated from data taken at three or more different distances (see Annex A). j) All operational modes shall be tested, including all frequency bands of operatio
23、n. k) EMC criteria for disturbance emission shall be met by compliance with radiated emission limits for specified devices and environments, which are subject to national regulations for BPL devices and installations. These limits are outside of the scope of this standard. 6.2 Immunity testing a) Te
24、sting shall be performed with equipment powered. b) All tests, except the surge tests, shall be performed with equipment operating and passing data. c) The auxiliary equipment (AE) and the simulated line shall be arranged so that the received signal level shall be set near the sensitivity threshold
25、of the EUT, such that any degradation in performance may be assessed. d) The surge test does not require the equipment to be transmitting data over the port under test during the application of the disturbance. The port under test shall be reconnected to demonstrate functionality if it was disconnec
26、ted during the Surge test. e) Where the test circuits call for characteristic impedance, a value of 150 shall be used as provided in most common test equipment. f) EMC criteria for immunity shall be met by compliance with performance criteria and test levels for specified devices and environments as
27、 described in Clause 8. 7. Disturbance emission measurement methods 7.1 Access equipment Access BPL devices are typically composite devices consisting of two equipment types (PLC system and ITE). Testing to the appropriate standards to determine compliance with these requirements shall be performed.
28、 11This conversion factor from magnetic field strength units to electric field strength units does not presume that a far-field condition exists at the point of measurement, although in practice the factor of 51.5 dB has been observed for BPL systems. The conversion is made to express measured resul
29、ts in the same terms used in the calibration of the measuring equipment. 15 Copyright 2011 IEEE. All rights reserved. IEEE Std 1775-2010 IEEE Standard for Power Line Communication EquipmentElectromagnetic Compatibility (EMC) RequirementsTesting and Measurement Methods 7.1.1 In-situ environment a) Th
30、e EUT shall include all BPL active devices, e.g., modems, BPL bridges, or repeaters. b) In-situ compliance testing shall be performed as specified by national regulations or in their absence on three typical installations. The three installations shall be identical in their BPL system attributes, in
31、cluding coupler type(s) and cable type(s) at representative power line location(s) (underground and overhead) and representative topologies as indicated in 4.1 and 4.2. If the system includes both underground and overhead installations, testing shall be performed at three locations of each type. c)
32、Compliance testing is intended to demonstrate the potential of BPL equipment to meet regulatory requirements in one or more configurations or installations. d) Simplified testing is intended for initial non-compliance assessments and to measure performance variations over time. 7.1.1.1 Equipment con
33、nected to overhead lines Measurements shall be performed at a separation distance defined by national regulation. This is either from the vertical projection of the overhead line (the lateral distance) or from the slant distance. For compliance testing: Testing shall be performed as defined by natio
34、nal regulations or at distances of 0, , , , and 1 wavelength down the line from the BPL coupling point on the power line. Wavelength spacing is based on the mid-band frequency used by the EUT, taking into account any fixed discrete channels of operation. In addition, if the mid-band frequency exceed
35、s the lowest frequency coupled onto the power line by more than a factor of two, testing shall be extended in steps of wavelength of the mid-band frequency until the distance equals or exceeds wavelength of the lowest frequency injected. (For example, if the device couples frequencies from 3 MHz to
36、27 MHz, the wavelength corresponding to the mid-band frequency of 15 MHz is 20 m (66 ft), and wavelength corresponding to the lowest injected frequency is 100 m (328 ft). Measurements shall be performed at 0, 5 m (16.4 ft), 10 m (33 ft), 15 m (49 ft), and 20 m (66 ft) down line, corresponding to zer
37、o to one wavelength at the mid-band frequency (see Figure 7). Because the mid-band frequency exceeds the minimum frequency by more than a factor of two, additional measurements shall be made at 10 m (33 ft) intervals until the distance down line from the coupling point equals or exceeds of 100 m (32
38、8 ft). Thus, additional measurement points shall be made at 30 m (98 ft), 40 m (131 ft), and 50 m (164 ft) down line from the coupling point.) For simplified testing: Measurements may be taken at only one location, closest to the BPL coupling point on the power line. The highest field strength is us
39、ually found here, any deviation from the maximum is acceptable for the purpose of this simplified testing. Figure 7 Example of BPL measurement points on overhead line for frequency range 3 MHz to 27 MHz 16 Copyright 2011 IEEE. All rights reserved. IEEE Std 1775-2010 IEEE Standard for Power Line Comm
40、unication EquipmentElectromagnetic Compatibility (EMC) RequirementsTesting and Measurement Methods 17 Copyright 2011 IEEE. All rights reserved. 7.1.1.1.1 Testing with LV service wiring to the building a) Testing shall be performed at three positions along the overhead line connecting to the building
41、 (i.e., the service wire), according to the spacing defined as follows. b) Where physically practical, measurements shall be performed starting at a distance of 10 m (33 ft) along the line from the connection to the building and continuing at 10 m (33 ft) intervals until 3 measurement points are tes
42、ted or the other end of the service wire is reached. If this test cannot be performed at three positions due to insufficient length of the service wire, a statement explaining the situation and test configuration shall be included in the technical report c) Measurements shall be performed at a later
43、al distance of 10 m (33 ft) from the overhead line connecting to the building. If necessary due to high ambient emissions or physical obstructions, measurements shall be performed at a lateral distance of 3 m (10 ft). Refer to Annex A for distance correction factors. 7.1.1.1.2 Radiated emission in t
44、he frequency range 30 MHz to 1000 MHz Using the general equipment setup in 6.1 and test configuration in 7.1, follow the measurement procedures in CISPR 16-2-3. For frequencies above 30 MHz an electric field sensing antenna such as a biconical or log periodic antenna shall be used. 7.1.1.1.3 Radiate
45、d emission in the frequency range 150 KHz to 30 MHz Using the general equipment setup in 6.1 and test configuration in 7.1, follow the measurement procedures in CISPR 16-2-3. For frequencies below 30 MHz, an active or passive magnetic loop shall be used. Field strength in dBA/m is converted to dBV/m
46、 by adding 51.5 dB according to the formula dBV/m = dBA/m + 51.5 dB. 7.1.1.2 Equipment connected to underground lines a) Underground line installations are those in which the BPL device is mounted in or attached to a pad-mounted transformer housing or a ground-mounted junction box and couples direct
47、ly only to underground cables. b) Measurements shall be performed as required by national regulations or in their absence at a lateral distance of 10 m (33 ft) from the ground-mounted or underground power transformer that contains the BPL device(s). If necessary due to high ambient emissions, measur
48、ements may be made at a lateral distance of 3 m (10 ft) with appropriate distance correction factors. c) In cases where Access BPL devices are coupled to low-voltage power lines, apply the appropriate LV measurement procedures as stated in 7.1.1.1.1. d) For compliance testing: Measurements shall be
49、made at eight uniformly-spaced positions around the perimeter of the ground-mounted or underground power transformer. Refer to Figure 8. Additional azimuth angles shall be examined to assure that the maximum emission has been measured. e) For simplified testing: The test antenna is slowly moved by hand around the location of the transformer, while emissions over the full span are monitored on the receiver. At points of maximum emissions for any given frequency, the test antenna is placed on its tripod and the measurement shall be repeated. I
