Current Grid Code Issues and Modifications
Last updated 1 September 2017
National Grid links in red below.
This modification (1/4) will set out within the Distribution Code and Grid Code the following compliance obligations in the EU Connection Codes:
1. Scope and applicability of the RfG, DCC and HVDC requirements for GB users
2. Set the x4 Type (A-D) MW banding levels for GB, as required in RfG
3. Set the GB Fast Fault Current Injection parameters, as set out in RfG
4. Set the GB Fault Ride Through requirements, as set out in RfG and HVD
This modification (2/4) will set out within the Distribution Code and Grid Code the following compliance obligations in the EU Connection Codes:
1. Set the Voltage & Reactive requirement in GB, as required in RfG and HVDC
2. Set the Frequency requirements in GB, as required in RfG and HVDC
This modification (3/4) will set out within the Distribution Code and Grid Code the following compliance obligations in the EU Connection Codes:
1. Set the System Management parameters, as set out in RfG and HVDC
2. Set the Compliance requirements, as set out in RfG, DCC and HVDC
This modification will set out within the Distribution Code and Grid Code the following compliance obligations in the European Network Code – Demand Connection Code (DCC)
1. Technical requirements for new* Transmission-connected Demand
Facilities; Transmission-connected Distribution Facilities and Distribution
2. Technical requirements for Demand Units used by a Demand Facility or
a Closed Distribution System to provide Demand Response Services to
* ‘New’ is defined as not being connected to the system at the time that the code enters into force and not having concluded a final and binding contract for the purchase of main plant items by two years after entry into force.
A joint Distribution Code and Grid Code Workgroup was established to examine:
- whether there is still a need for RoCoF based Loss of Mains protection;
GC0035 represents Phase 1 work which looked at generators with a capacity greater than 5MW. Meetings 1-20 were to discuss Phase 1 work which was approved on 24 July 2014 and the Authority Decision can be found at the relevant tab below.
GC0079 represents Phase 2 work which is looking at generators with a sub-5MW capacity. Meetings 21 onwards discuss Phase 2 work.
This Distribution Code public consultation is seeking the views from industry stakeholders on proposed changes to the Distribution Code, Engineering Recommendations G59 and G83 recommended by the Joint Panel working group GC0079.
The workgroup recommends the modification of the Distribution and Planning Code, Engineering Recommendations G59 and G83 to ensure that all embedded generators with a commissioning date on or after the date of implementation of these proposals comply with the following:
a) That if rate of change of frequency (RoCoF) protection is used as Loss of Mains protection, the applied setting should be 1Hzs-1 with a definite time delay of 500ms.
b) That all generation (whether using discrete relays or loss of mains techniques included in the overall control scheme for type tested generation) should demonstrate stability for appropriate RoCoF and vector shift disturbances
c) That vector shift protection technique should not be used as Loss of Mains protection.
A comprehensive consultation pack with further details can be downloaded here from the Distribution Code Website.
Responses to this consultation should be sent to the Distribution Code Review Panel Secretary at firstname.lastname@example.org by 17:00 Friday 1 September2017 on the pro-forma provided expressly for the purpose. Responses after this date may not be considered.
Contact: David Spillett - Code Administrator
The Review of Harmonics Assessment Standards and Processes Workgroup was established to examine and make recommendations to review the standards and processes employed by electricity transmission and distribution network owners to assess harmonics and, in particular, produce a report describing any changes that are considered necessary to Engineering Recommendation G5/4-1 (Planning Levels for harmonic Voltage Distortion and the Connection of Non-Linear Equipment to Transmission Systems and Distribution Networks in the UK.
This workgroup will set those parameters left to national interpretation in the Requirements for Generators European Network Code and make sure that the GB codes align with it – so making necessary changes to the Grid Code, Distribution Code and supporting documents or Engineering Recommendations. This Modification has now been withdrawn and replaced by GC Modifications 100,101 and 102.
.GC0062 Fault Ride Through working group
It is proposed that the Grid Code is changed to provide clarity to the fault ride through performance for Synchronous Generating Units. Grid Code paper pp12/04 raised concerns over the ability of Synchronous Generating Units to meet the current GB Grid Code fault ride through requirements, particularly in respect of faults lasting longer than 140ms. To address this issues, consideration is being given to the early adoption of the Fault Ride Through requirements for Synchronous Generators as detailed in the ENTSO-E Network Code Requirements for Generators (RfG) which it is believed will address these issues.
Proposals to develop the Frequency Response provisions of the Grid Code under GC0022 did not reach a conclusion. National Grid believes that there are a number of outstanding defects with the Frequency Response provisions of the Grid Code which should be addressed in a new Workgroup (GC0087).