Observations and clarifications of measured trends in PQ disturbance levels in the Dutch HV and EHV grid

The Dutch Electricity Grid Code defines requirements for the quality of the supply voltage. For HV (110kV/150kV) and EHV (220kV/380kV), every commercial connection must be equipped with a PQ meter, resulting in approx. 130 PQ meters. The paper reviews the measured trends between 2019 and 2023. It can be concluded that overall, compared to 2019, steady state voltages and voltage unbalance have increased, measured THD has decreased for most nodes and no major changes are noticeable with respect to voltage dips. TenneT is taking various measures to remain compliant with the Grid Code requirements. As most of the power quality phenomena propagate to lower voltage levels, this trend analysis is also important for the DNOs.