Low Voltage Network Simulation with the Faraday Grid
by Matthew Williams and Alexandros Kleidaras
Low Voltage (LV) networks are usually located in the distribution circuit of an electrical power grid and carry electric energy from distribution transformers to the electricity meters of end customers. The primary or feed voltage level is usually rated at 33/11 kV, while secondary or consumer voltage levels are rated at 230/415 V.
Most modern secondary LV networks are operated at an AC rated voltage of 100-120 V or 230-240V and at a frequency of 50 or 60 Hertz depending on a specific country’s rating. In Europe and most of the world, 220-240V is the dominant choice, while in North America 120V is the standard. Distributed transformers, which are placed across feeders in the grid, convert the voltage from a medium to a low voltage level thus making it suitable for direct consumption by end users.
In recent years, there has been significant growth in renewable energy generation. Significant quantities of generation capacity are now installed throughout the distribution grid, impacting the fundamental design paradigm of the grid itself resulting in congestion and increased losses in the network. Other factors that contribute to the integration challenge are the intermittence and volatility of the generation, poor power quality, thermal limits of grid elements, power system stability, and security of supply.
Despite the current grid structure not being suitable to carry large amounts of power from renewables, distribution grid operators are required by law to connect these generation systems to their grid, and at the same time provide a reliable supply voltage to consumers which lies within their permissible tolerance limits. This is resulting in a well-recognised control problem for grid operators and the potential for rapidly rising mitigation costs estimated by UKERC to be between £15 and £45/MWh at 50% penetration levels.
Faraday Grid Solution
The Faraday Exchanger (FE) has the ability to control Voltage and Power Factor outputs in all parts of the grid, without causing any transient or harmonics effects. It filters out harmonics, increasing the quality of service to consumers. This greatly increases the capability of electricity networks to accept increased levels of Renewable Energy Sources whilst simultaneously increasing efficiency, stability and flexibility.
In order to demonstrate the regulation capabilities of the FE on the LV network, three sets of simulations demonstrating the ability of the grid to dynamically manage the voltage, power factor and harmonics, and increase the network’s capability to accept more variable renewable energy, were carried out with conventional transformers, Online Tap Changers (OLTCs) and Faraday Exchangers were carried out.
From the results obtained in the simulations, it was concluded that integrating the Faraday Exchanger into UK LV networks demonstrated a number of significant gains such as:
- Increasing the renewable generation carrying capacity of the grid
- Dramatically reducing reactive power within the grid
- Increasing integration of distributed variable renewable generation into the grid can also be achieved, while simultaneously increasing the efficiency of the network.
When rolled out across a wider system of LV networks, the Faraday Grid technology can enable a quantum shift in energy system architecture to a new decentralised, flexible and reliable system.
For more information, please download the original White Paper by Matthew Williams and Alexandros Kleidaras HERE.