Overview

ABSTRACT

DNOs will be able to reduce the level of conventional reinforcement that would otherwise be required to address the growth in low-carbon technologies (LCTs) by, instead, turning to smarter lower cost solutions.

The learning from our CLNR project has shown that there is not a ‘one-size-fits-all’ solution to address the impact of LCTs and we have demonstrated that the solutions can start relatively simply and evolve over time as the complexity of the constraint increases.

Power flow solutions also often solve voltage issues, which gives a logical order for DNOs, as follows:

Confirm the issue:

• Model the issue to identify potential capability gaps
• Where necessary, monitor the network to validate the model

For thermal issues:

• Where cost-effective, carry out a bespoke thermal rating study, e.g.

1. transformer thermal tests;
2. soil thermal resistivity tests;
3. wind speed measuring/modelling.

• Invite tenders for demand side management (DSM) (demand side response, generation side response and electrical energy storage), priced against deferring the lowest cost conventional alternative.
• Where multiple DSM resources, which are capable of addressing multiple series power flow constraints exist, deploy an area coordinating control scheme.
• Reinforce where required to close the remaining capability gap.

For any remaining voltage issues:

• Apply default 3% load-drop/generation-rise compensation setting on all active voltage control devices.
• Carry out bespoke voltage setting analysis for:

1. increased load-drop/voltage-rise compensation settings;
2. tighter dead-bands.

• Where contracts permit, direct controllable distributed generation (DG) to operate with bespoke reactive power settings (e.g. PV mode).
• Where contracts permit, direct controllable DG to operate with bespoke real power settings (e.g. trimming real output to avoid breaching a defined upper voltage limit at the terminals).
• Invite tenders for DSM (for both real and reactive power to address voltage issues), priced against deferring the conventional alternative.
• Deploy as many additional control devices as required, with bespoke analysis of settings:

1. in urban areas –­ on load tap changer (OLTC) at the local substation serving the affected cluster;
2. in rural areas – high voltage (HV) regulators.

• Deploy area control to coordinate the set-points of voltage control devices (including constrained DG).
• Reinforce where required to close the remaining capability gap.

The table below provides an overview of how the learning from CLNR will be taken forwards:

Method	Northern Powergrid Deployment
New customer demands for network planning	We have used the rich CLNR information set on existing customers’ behaviour to propose updates to the existing industry modelling standards ENA-ACE 49 and 105, i.e. We have:a) published network design coefficients (p and q values in ACE 49/105 terminology, related to mean and standard deviation values of consumption for each half hour of the nominal peak day) for general domestic customers with high, medium and low annual consumption;b) published new sets of design coefficients, in an industry standard format, suitable for existing industry standard tools, to represent emerging customer behaviour, specifically:i) electric vehicles;ii) heat pumps;iii) solar PV.
Time of use tariffs (ToU)	We already have ToU tariffs for existing half-hourly metered customers and are establishing ToU tariffs for the distribution element of our profile class 1-8 customers, with a April 2015 implementation date, Changes to billing arrangements have a Nov 15 implementation date.This preparation lays the foundation for DNOs to influence the price incentives given to customers with the roll out of smart meters.

Back to Project Library