EMI-EMF update:
Recent achievements and work going on in relevant WG’s
CIGRE-CIRED
WG C4.04[1] : “EMC and EMF – general aspects”
"EMC within generating plants, transmission systems and industrial installations"
Some electrical safety concerns (step and touch voltages) also taken into account
EMC (EMI)
· Guides and tutorials
- Guide 124 : “Guide on EMC in Power plants and substations” (1997)
- Guide 104 : “Magnetic field in HV cable systems” (1996) (JTF 36.01-21)
- Guide 21: “Electric and magnetic field produced by transmission systems (1980) (36.01)
- Guide 20: “Interference produced by corona effect of electric systems (1974 + add 1997) (36.01)
· Better characterisation of some disturbances
Review of most of the available measurement data published since 1990 and dealing with GIS, AIS, Fast transients, CM currents, transient fields.
Publication at the CIGRE Paris 2002 session of paper 36-108 entitled:
“EMI characterization of HV substations – updated data and influence on immunity assessment”
· Assessment of immunity (emission) characteristics of substation installations
- Study of existing data to assess some basic standards (Fast transients / Surges / Oscillatory – Radiated versus conducted ...)
- A position paper on transient immunity tests has been forwarded to IEC [ref 77B(Firenze/Secretariat)13].
(the oscillary wave test 61000-4-12 is presently under revision)
- Proposals for in situ testing (input to IEC)
EMF
· TF C4.04.01: Measurements and modeling
This TF aims at setting up reliable EMF measurement methods and procedures in the vicinity of utilities power installations. Alternative calculation methods will also be proposed.
· TF C4.04.02: Magnetic field mitigation techniques
A review of publications has been done and more than 80 references are made available to the TF members
A technical brochure is scheduled by end 2004
· TF C4.04.03: Magnetic field indices (to be set up in October 2003
This new TF aims at proposing and defining a set of quality indices able to characterize the magnetic field level in given locations, taking into account its statistical behaviour; e.g. field level not exceeded during 95 % of the time.
The purpose is to make at disposal to decision makers correct assessment methods but not to propose any limit.
Relations with IEC / Cenelec
- Link with IEC and more particularly with SC 77B: (e.g. Comments on transient immunity tests )
- IEC 61000-6-5 (UNIPEDE immunity spec.):
Generic standards : Immunity for power station and substation environments.
- IEC 106 and CLC 106X: EMF associated with human exposure
WG C4.02[2] : “ EMC with telecommunication circuits, LV systems and metallic structures ”
· Guides and tutorials
Guide 95 : “Guide on on the Influence of HV AC Power Systems on Metallic Pipelines” (1995)
(Mainly influence under fault condition)
”Methods for measuring the earthing of transmission towers equipped with earthing wires” (foreseen by end 2003)
· AC corrosion
Guide for ac corrosion on metallic pipelines due to the influence of ac power lines (In cooperation with CEOCOR)
· Non constant fault current (safety concern)
· Harmonic currents (interferences on telecom circuits)
· GSM base station in power pole/towers (collaboration with WG C4.04 and with ITU-T)
· Relation with other bodies :
Input to CENELEC (pr EN 50351 and 50352) « Basic Standard » and « Limits relating to the influence of electric power supply and traction systems on telecommunication systems »
Input to and link with ITU-T SG 5 : Recommendations K33 (Limits for people safety related from coupling from ac electric power) Proposals for new a safety level for long fault durations. Also input to K53 (Values of induced voltages to establish responsibilities) and mainly to the new K.bsp concerning radio base stations on HV towers.
CC 05 : “Protection of distribution networks against lightning”
Preparation of a guide (tutorial) on the protection of MV and LV networks against lightning
(Synthesis presented at CIRED 97)
· Link with TF C4.01.01 (Lightning Induced Overvoltages) and WG C4.04
· Input to IEC TC64: IEC 62066: “General Basic Information Regarding Surge Overvoltages and Surge Protection in LV AC Power Systems”
· Future input to IEC TC 81
Standardization (not exhaustive)
IEC
SC 77 B: Electromagnetic compatibility- HF phenomena
· Mainly revision and updating of basic standards
WG 11: 61000-4-12: Damped oscillatory waves - Extension up to about 50 MHz
CISPR: EMC-Emission above 9 kHz
· CISPR-G: Interference relating to information technology equipment – modification to CISPR 22: includes equipment used for data transmission across a power supply network
· CISPR-B : Includes now Interferences related to overhead power lines and to HV equipment
TC 99: Power installations above 1 kV ac and 1.5 kV dc
· Project 61936-1: “Common rules” – chapter 9 Earthing systems (FDIS stage)
TC 106: Methods for the assessment of electric and magnetic fields associated with human exposure
· WG 1+3: Basic standards, WG 2+4: Product std, WG 5 Generic std
· WG 1: Project 62226: “Calculation methods of induced current in human body by electric or magnetic field in low or intermediate frequency range” – CDV stage
TC 81: Lightning protection
· Will completely revised the structure of the existing standards (LPS, risk assessment, LEMP) into a new standard with reference IEC 62305
· Intends to start a NWP on “Incoming services – Powerlines”
CENELEC
Mandates of European Commission (European Directives)
TC 210: Electromagnetic compatibility
· WG 3: prEN 50352: Limits relating to the influence of electric power supply and traction systems on telecommunication systems.
prEN 50351: Basic standard for the calculation and measurement methods relating to the influence of electric power supply and traction systems on telecommunication systems
BT(IT/NOT)75: Electromagnetic interferences produced by power lines on metallic pipelines
BT(IT/NOT)76: Electromagnetic interference produced on TLC lines by harmonics flowing on power lines
TC106X: Human exposure to electromagnetic fields
According to the Dresden agreement the main activities of this TC are transferred to IEC except for what concerns limits or when the time schedule proposed by IEC is not acceptable.
TC99X: Power installations exceeding 1 kV ac and 1.5 kV dc
· HD 637-S1 – chapter 9 Earthing systems
ITU-T
SG5: Protection against electromagnetic environment effects
· Guidelines - Tutorials: “DIRECTIVES”
Vol II – Calculating induced voltages and currents in practical cases (1990/2000)
Vol V – Inducing currents and voltages in power transmission and distribution systems
(1990/2000)
Vol VI – Dangers and disturbances (under revision in cooperation with WG C4.02)
· Regulations: “RECOMMENDATIONS”
K 33: Limits for people safety related to coupling into telecommunications system from a.c. electric power and a.c. electrified railway installations in fault conditions
(Admissible limits)
K 53: Values of induced voltages on telecommunication installations to establish telecom and a.c. power and railway operators responsabilities
K.bsp: Use of power line towers for radio base stations (draft)
2
JH/WG_Update/04-2003/rev1
[1] Former WG 36.04
[2] Former WG 36.02