1. DRAFT Slides for Discussion - Standards, Reports and Recommendations
G5/4 Review Group
DRAFT Slides for Discussion - Standards, Reports and Recommendations

2. Standards, Reports and Recommendations
~67% of CENELEC European Norms (ENs) identical to IEC
European countries dominate IEC and as a result many IEC standards can easily be adopted as CENELEC ENs without any additions (about two thirds of CENELEC ENs are identical to IEC, a further 8% have some modification). There are no requirements for BSi to adopt IEC standards however there is a requirement for ENs to be adopted. When adopted the ENs are published as BS ENs and are identical to the originals. IEC and CENELEC run a parallel voting scheme which operates on documents that are identified at an early stage as being suitable.
All ENs become British Standards

3. Standards, Reports and Recommendations
Compliance with European Norms (EN) is mandatory
Compliance with IEC Technical Reports and Standards is not mandatory
But can be stipulated in a bilateral agreement
For the Transmission System in Great Britain, the Grid Code refers to the Planning and Compatibility Levels in G5/4
For Distribution Networks, the Distribution Code states that the harmonic content of a load shall comply with the G5/4-1 limits

4. Grid Code Connection Conditions 6.1.5(Voltage Waveform Quality):
“(a) Harmonic Content
The Electromagnetic Compatibility Levels for harmonic distortion on the Onshore Transmission System from all sources under both Planned Outage and fault outage conditions, (unless abnormal conditions prevail) shall comply with the levels shown in the tables of Appendix A of Engineering Recommendation G5/4. The Electromagnetic Compatibility Levels for harmonic distortion on an Offshore Transmission System will be defined in relevant Bilateral Agreements.
Engineering Recommendation G5/4 contains planning criteria which NGET will apply to the connection of non-linear Load to the National Electricity Transmission System, which may result in harmonic emission limits being specified for these Loads in the relevant Bilateral Agreement. The application of the planning criteria will take into account the position of existing and prospective Users’ Plant and Apparatus in relation to harmonic emissions. Users must ensure that connection of distorting loads to their User Systems do not cause any harmonic emission limits specified in the Bilateral Agreement, or where no such limits are specified, the relevant planning levels specified in Engineering Recommendation G5/4 to be exceeded.”

5. Distribution Code
DPC4.2.3 Voltage Disturbances and Harmonic Distortion
“(b) The harmonic content of a load shall comply with the limits set out in DGD, Item 1 Engineering Recommendation G5/4-1,”Planning levels for harmonic voltage distortion and the connection of non-linear equipment to transmission and distribution systems in the United Kingdom.”

6. Standards, Reports and Recommendations
The main documents the G5/4 Review Group needs to consider are
BS EN :2002 “Compatibility levels for low-frequency conducted disturbances and signalling in public low-voltage power supply systems”
BS EN :2003 ‘’ Compatibility levels for low-frequency conducted disturbances and signalling in public medium-voltage power supply systems”
IEC TR :2008 “Assessment of emission limits for the connection of distorting loads to MV, HV and EHV power systems”
BS EN 50160:2010 “Voltage characteristics of electricity supplied by public electricity networks “
G5/4-1 “Planning Levels for harmonic Voltage Distortion and the Connection of Non-Linear Equipment to Transmission Systems and Distribution Networks in the United Kingdom”

7. Standards, Reports and Recommendations
BS EN
(LV) & 2-12(MV)
IEC TR
(MV,HV & EHV)
BS EN 50160:2010
(LV & MV)
G5/4-1
Voltage Levels
LV and 1kv<=Un<=35kv
35kv<=Un<=230kv & Un>230kv
LV and 1kv<=Un<=150kv
LV,11,22,33,66,132,275 & 400KV
Defined Compatibility Levels
YES
BS EN levels MV only
Defined Planning Levels NO
Harmonic order
up to and included 50th
up to and included 25th

8. Harmonics beyond 50th harmonics & CIGRE update
There is no standard or guidance document that indicates requirement to limit harmonics beyond 50th
apart from BS EN :2003 which suggests limits(0.2%) up to 35kV.
CIGRE advisory group has agreed that work is required on ‘guidance’ document
Timescales have not been agreed
G5/4 review group could consider
The requirement for limits above the 50th
Need for
Timescales
Appropriate means for developing criteria