Martin Pieschel

Multilevel STATCOM with power intensive energy storage for dynamic grid stability - frequency and voltage support

The developing political and environmental reforms are driving the rapid evolution of todays power systems. There is a steady increase in the electrical energy being fed from renewable energy sources like wind and photovoltaic systems while shutting down large thermal power plants. This trend has a major impact on the performance of the electrical power system networks especially with respect to their dynamic behaviour. Phasing out of existing conventional synchronous generators will adversely affect auxiliary services like voltage control and frequency regulation. The paper discusses one of the solutions to cope with these challenges: the use of Modular Multilevel Converter based STATCOM i.e. SVC PLUS® with power intensive energy storage (SVC PLUS ES) which can significantly contribute to the stable operation of the power system. The successful frequency and voltage support in transmission grids will be presented. Furthermore the design of SVC PLUS ES with supercapacitors as storage technology will be shown.

Modular multilevel converter with short-time power intensive electrical energy storage capability

The developing political and environmental reforms are driving a fast change in the energy mix of many nations. The increasing electrical energy being fed from renewable energy sources (e.g. wind and photovoltaic) impacts the dynamic behaviour of the power grid. Phasing out of existing conventional synchronous generators will adversely affect auxiliary services like voltage control and frequency regulation. Nowadays, there is no requirement by grid operators for these decoupled generation plants to provide any inertial support to the grid. Hence the integration of renewable energy sources could not serve as a complete replacement of the conventional generation. These challenges require identification of new solutions, which enhance dynamic performance and improves stability of the power grid. This paper presents one of the possible solutions to cope up with these challenges. This is based on a Modular Multilevel Converter based STATCOM i.e. SVC PLUS with power intensive storage. Preliminary results show a significant contribution of the proposed system to the dynamical behaviour and stability of the power grid.

Design and evaluation of a test rig for full-size grid frequency stabilizer modules with ultracapacitors

In order to stabilize the grid frequency in case of sudden loss of power generation, an injection of real power is needed. For this, a Static Var Compensator (SVC) can be combined with ultracapacitors, forming a grid frequency stabilizer. To prove the feasibility of this novel combination, the paper shows the realization of a 1 MW class test rig for full-size modules. Single modules are tested using a second module and connecting them at their AC front-end. The control of the AC/DC and DC/DC converters is described and the performance of the test field is shown in measurement results.