Mathias Duckheim

Voltage and power flow oscillations induced by PV inverters connected to a weak power distribution grid

In this paper, we present simulation results for a basic setup in which a photovoltaic inverter and a load are connected to a weak power distribution grid. We use both DIgSILENT PowerFactory, with a standard PV model including a reactive power controller for voltage support, and MATLAB/Simulink as simulation software. We identify conditions under which load changes result in voltage oscillations or even instability. Potential ramifications for PhotoVoltaic (PV) inverter grid codes are briefly discussed.

Overview of recent control technologies for future power systems

Abstract The increasing integration of renewable power generation in power systems poses new challenges to power system control. In this article, we describe a multi-layer power system control architecture that addresses these challenges and comprises economic planning, supervisory power control, as well as voltage and frequency control as main layers. Several parts of this architecture have already been developed and tested on diverse components including building energy management, micro grid management and wind park control. We provide an overview of these applications and indicate white spots in this control architecture that require further research.

From brown coal to a rural energy landscape — Orchestration of storage and electric mobility to foster decentralized energy management

The “City of Kerpen” is a rural administration unit of eleven villages near Cologne, Germany. With its 64,000 inhabitants, this region has been strongly dominated by surface mining of brown coal and the generation of electricity burning this fossil energy source in huge power plants. This is going to change dramatically. After having founded municipal utilities which own the majority of the power and energy distribution grid of the city area, the City of Kerpen plans and operates the fast transition towards flexible and decentralized generation, storage and consumption of electric, chemical and thermal energy in strong conjunction with smart traffic management. This is done in several master plans which cover built-up residential estates, but especially development areas of residential buildings as well as commercial zones. Also areas covered by infrastructure such like highways or railway routes are included in that they provide surfaces easily available for large-scale photovoltaic and/or wind power generation. This paper introduces the concepts for which the outlines plus some detailed concepts have been developed during the last years, an important step being the mentioned foundation of municipal utilities. The authors discuss the present status of this development in the light of recent R&D results which focus on the efficient management between large scale EV traffic and decentralized electric energy generation and storage on all scales. An outlook is given how the activities of the City of Kerpen could be used to upscale these R&D results from lab scale to real-world size.