Challenges and Pitfalls of Implementing Realistic Simulations to Study Harmonic Levels in Public Low Voltage Networks

The energy supply system in many countries is currently undergoing a period of transition. New technologies like energy efficient lighting, small photovoltaic units or electric vehicles have the potential to affect significantly the power quality, e.g. harmonics, in future low voltage networks. Therefore, harmonic simulations are becoming increasingly important. However, depending on the level of detail, they require a large number of input data regarding the network components and the connected customer installations. This data can be difficult to obtain and usually, certain assumptions have to be made. This paper demonstrates exemplarily how different simplifications influence the results of harmonic studies in networks with a large number of distributed photovoltaic installations. It starts with a very simplified simulation, which is then more and more extended by including e.g. the existing equipment or the background distortion. Finally, a probabilistic network simulation is performed and the results are compared with each other.