Impact of advanced inverter functions on low-voltage power grids

Abstract

In today's power grid, a great number of inverter-based distributed energy resources (DERs) are connected and are mainly designed to supply power without considering the voltage and frequency deviations of the grid. Therefore, distribution system operators (DSOs) are challenged with an increase in grid events because of the random implementation of DERs. Voltage levels can vary beyond predefined limits at the point of connection and are currently not evaluated by DSOs. Summarized here is the development of a simulation model for evaluating the impact of support functions integrated in inverter-based DERs. The model aims to help grid operators simulate voltage and frequency events and study the impact of DERs to the grid with respect to different settings of integrated support functions. A model is developed in MATLAB/Simulink conforming to European standards and regulations. Grid dynamics can be evaluated by imitating voltage and frequency deviations. Support functions can be either adjusted according to the situation or turned off. Together with adjustable settings according to DSO request, this model offers flexibility and insight in the capabilities of DERs to solve voltage and frequency issues. Case studies show that the model corresponds to expected behaviour and can be used for further development.In today's power grid, a great number of inverter-based distributed energy resources (DERs) are connected and are mainly designed to supply power without considering the voltage and frequency deviations of the grid. Therefore, distribution system operators (DSOs) are challenged with an increase in grid events because of the random implementation of DERs. Voltage levels can vary beyond predefined limits at the point of connection and are currently not evaluated by DSOs. Summarized here is the development of a simulation model for evaluating the impact of support functions integrated in inverter-based DERs. The model aims to help grid operators simulate voltage and frequency events and study the impact of DERs to the grid with respect to different settings of integrated support functions. A model is developed in MATLAB/Simulink conforming to European standards and regulations. Grid dynamics can be evaluated by imitating voltage and frequency deviations. Support functions can be either adjusted according to the situation or turned off. Together with adjustable settings according to DSO request, this model offers flexibility and insight in the capabilities of DERs to solve voltage and frequency issues. Case studies show that the model corresponds to expected behaviour and can be used for further development.