Supported by: (FKZ 0325757G)
Optimizing Efficiency and Grid Compatibility from the View of Harmonics of Generation Plants
The aim of the project is the improvement of the current procedure to determine and evaluate the emission of harmonics by electricity generation units and electricity generation plants for all grid levels. Especially the prior state of the grid and the grid’s resonance points at a specific grid connection point are to be considered. To achieve the overall aim of the project, the time- and frequency-dependent grid impedance will be determined via measurements on the medium voltage level up to 20 kV, which will be performed with a measurement container that was developed at the Helmut-Schmidt-University (HSU). Via the determination of the frequency-dependent grid impedance, a better integration of power generation units and electrical loads that are coupled to the grid via power electronics can be achieved. This can optimize the planning and implementing of wind and photovoltaic plants.
Electricity generation plants change the properties of the grid because they have, just like the grid itself, an internal impedance. Their internal impedance is also time- and frequency-dependent and superimposed on the grid impedance. This superimposition can have positive and negative effects on the quality of the grid. The measurement of the grid impedance provides more precise insights on the connection capacity at a point of common coupling (PCC), in comparison to the currently used estimation procedure that relies on tabular values and simulation programs. For this, requirements will be defined, validation procedures created and permissible uncertainties defined. The focus at the HSU lies on the development of new approaches to modelling grids and their prior state. Systematic scientific research achieves a better understanding of the emission of harmonics and their propagation at frequencies up to 9 kHz.With this, current evaluation procedures of harmonics can be improved to exploit unused grid capacities for the connection of wind and photovoltaic power plants at all grid levels. At the same time, disturbances on the grid and plants, due to harmonics, can be avoided.
The focus at the HSU lies on scientific research tasks. Due to experience and prior work in the area of impedance measurement, the HSU was put in charge of the measurement campaigns at the generation plants. In terms of grid levels, the activities at HSU essentially cover the medium voltage level and partially the high voltage level. In particular, it’s about the development of new evaluation procedures regarding harmonics. This knowledge is to be taken into consideration in standards and to be made accessible to the public through publications.
Letzte Änderung: 16. July 2018