A Dynamic RMS-Model of the Local Voltage Control System Q(V) Applied in Photovoltaic Inverters

The additional integration of distributed energy resources (DER) into today’s electricity distribution grids is planned and anticipated in many countries. As a consequence, local voltage stability problems will be multiplied and their prevention will become crucial to the security of electricity supply. Voltage source inverters represent the largest share of grid connection solutions. Their ability of almost independent reactive power supply can be utilized to manage local voltage- and in particular local voltage rise problems in distribution grids. Of notably interest are the widely researched approaches using cosφ(P)- or Q(V)- characteristics. While the implementation of a cosφ(P)- characteristic is simply done by an open-loop structure, a control system such as Q(V) includes a feedback loop and is therefore exposed to possible unstable operation. This instability is subject to the internal control structure and parameterization of the respective inverter, which is usually not publicly accessible. Yet, knowledge of stability and dynamic performance of new technologies is essential for their broad acceptance. In this paper, two dynamic reactive power control RMS-models are developed from and evaluated with laboratory measurements.     «

The additional integration of distributed energy resources (DER) into today’s electricity distribution grids is planned and anticipated in many countries. As a consequence, local voltage stability problems will be multiplied and their prevention will become crucial to the security of electricity supply. Voltage source inverters represent the largest share of grid connection solutions. Their ability of almost independent reactive power supply can be utilized to manage local voltage- and i...     »