Coordinator: Paul Wright

Time synchronized tools are developed and deployed to measure and locate significant or aggregated power quality (PQ) disturbances as they propagate the wider grid network. This developed knowledge about propagation mechanisms through different network configurations and components and, for a given network, it provided vital information for system designers and operators. 

In the previous SmartGrid I project, the capability for on-site PQ measurements was developed and utilized in different power networks encompassing a range of renewable generation and loads.  Whilst these and other surveys can be used to determine the local effect of a particular disturbing influence, its effect on the wider network remains unknown.  For example, the generation of local harmonics by a large installation such as an high-voltage DC (HVDC) station could be significant, triggering the need for expensive mitigation equipment; however, if that disturbance had been ‘naturally’ attenuated once at the wider grid level, the need for this mitigation can be relaxed. Conversely resonances in the network could give rise to an increase in the disturbance at the wider network level.   

The nature of the PQ propagation will depend on each specific network topology and impedance and in order to draw any generic conclusions about propagation mechanisms, it is necessary to determine the propagation characteristics using a selection of distribution and transmission networks with various significant PQ disturbances. Reconciliation of the results with each grid topology model needs to be performed to assess the system-level impact of various PQ disturbances, leading to improved grid management/planning and appropriate constraints in future normative standards and grid codes. 

To combat this challenge, a PQ propagation measurement tool based on GPS time-synchronised measurements both at the locality of the connected disturbance and in several remote locations in the grid used to assess the extent of attenuation/amplification is developed and demonstrated. To determine the PQ propagation, a variety of different grid types have been observed, and different PQ events are captured to determine the propagation characteristics over changing grid conditions. Finally, a harmonic power flow analysis tool is developed using synchronized harmonic phase information from several locations in-order to identify the source of a disturbing influence in a network. 

Several state-of-the-art working smart grids provided the ideal environment to develop and deploy these techniques. In Denmark, a fully contained island with multiple renewables and smart grid elements have been instrumented with multiple PQ analysers to analyse PQ propagation. In the Netherlands, a working medium-voltage/low-voltage smart grid, the Alliander LiveLab, has been used to determine PQ propagation in the urban setting. 

For more information, see  the project webpage >>