Inverter-based hybrid compensation systems contributing to grid stabilization in medium voltage distribution networks with decentralized, renewable generation

Medium voltage grids are subject to a change in load situation due to the installation of decentralized generation plants. Predominantly load symmetry, active and reactive power as well as the required capacity of earth fault compensation are affected. Inverter-based plants as well as consumers using switching power supplies or phase control cause distortions of frequency. Simultaneously, electrical energy storage is gaining importance within rural distribution networks to compensate fluctuating generation plants. A hybrid compensation system includes a transformer, a multiphase inverter, diverse storage systems and a communication-capable control unit, which may be connected to the control center of the distribution system operator (DSO). It is object to current research activities to design and evaluate the functions of the superordinate control unit, which has to parametrize individual components, coordinate the energy flows between them and to embed several measuring instruments. Within the present work, basic considerations for design of system control are outlined.