Web-based Constraint Analysis using Ipsa 2

Lincolnshire Low Carbon Hub

The Low Carbon Hub for East Lincolnshire has been designed to test a variety of new and innovative techniques for integrating significant amounts of low carbon generation on to electricity networks, in an effort to avoid the costs that would normally be associated with more conventional methods. The project has received £3m of funding from Ofgem's Low Carbon Networks Fund Tier 2.

In this project, we are seeking to explore how the existing electricity network can be developed ahead of need and thus deliver low carbon electricity to customers at a significantly reduced cost in comparison to conventional reinforcement.

Analysis Description

This web site and the network constraint analysis have been developed by Ipsa Power for Western Power Distribution Ltd. Smarter Grid Solutions have performed validation of the results to ensure that they are sufficiently representative of the network constraints that may be experienced.

A short breakdown of the constraint analysis is provided in order to provide an insight into the data and assumptions used to obtain the results.

The constraint analysis is based on an accurate power system model of the WPD Skegness network. This model includes the 132kV and 33kV circuits and the transformers connected to them. The model also includes;

  • Existing generators connected to the distribution system
  • Approved generators that are in the process of being connected to the distribution system
  • Existing distribution system loads

The constraint analysis performs a series of power flow calculations in order to determine if the proposed generator causes an issue on the distribution network. These power flow calculations are performed using demand and generation profiles in order to best represent the typical variations in each. Demand and generation profile contains over 26000 data points to represent 18 months of half hourly demands. The demand profiles are used to represent the existing customers connected to the system. The generation profiles are used to represent both the existing and proposed generators. Both demand and generation profiles used are as follows;

  • Demand data is based on actual network measurements at various WPD substations
  • The wind generation profile is based on wind speed data obtained at a Skegness weather station. Calculations are performed to convert the wind speed data to a typical wind turbine electrical output
  • The solar generation profile data is based on typical solar array daily profiles
  • The synchronous generation profile is a constant output assuming it is always on

The constraint analysis is performed using the Ipsa 2 software developed by Ipsa Power. This is used to automate the power flow studies allowing each of the 26000+ demand points to be quickly analysed. The constraint analysis itself is performed as follows;

  • The proposed generator is connected to the nearest 33kV circuit based on the geographic distance
  • The appropriate generation profile is applied to the proposed generator
  • The power factor and smart grid options are enabled as required
  • Power flow analysis is then performed for each of the 26000+ demand points
  • The network voltages and power flows are checked at each demand point to identify if there are any overloads or voltage issues
  • Each overload and voltage issue is checked against the generation profile to determine both the energy generated and the energy lost due to network constraints
  • The results are then reported on the web site