VOLTAGE SUPPORT IN DISTRIBUTION GRIDS USING HEAT PUMPS

ABSTRACT This paper investigates the potential of heat pumps to increase the self-consumption of households and t

Optimized Planning of Distribution Grids Considering Grid Expansion, Battery Systems and Dynamic Curtailment

The increasing integration of renewable energies into the grid is calling for the expansion of the power transport capacities in the distribution system. Yet, the expansion of the grid could require long authorization procedures and cannot be always asserted. Therefore, a higher utilization of the existing grid is becoming increasingly necessary today. This paper proposes a new time series-based planning method for distribution systems using classical grid expansion instruments as well as innovative planning instruments such as battery storage systems (BSS) and dynamic power curtailment (DPC). These planning instruments could be applied individually or combined. The aim of the BSS and DPC application is to enable a higher utilization of the grid at minimal costs. The proposed method, which has been implemented as an automated planning algorithm, determines the cost-optimal grid reinforcement measures that ensure the prevention of prognosticated congestions in the considered grid. Furthermore, the application of the proposed planning method on the considered power system has proven that a combination of BSS and grid expansion could be more economical than an individual application of BSS and grid expansion

Identification of Grid Impedance by Broadband Signals in Power Systems with High Harmonics

Grid impedance is an important parameter and is used to perform impedance-based stability analysis for the operation of grid-connected systems, such as power electronics-interfaced solar, wind and other distributed power generation systems. The identification of grid impedance with the help of broadband signals is a popular method, but its robustness depends strongly on the harmonic disturbances caused by non-linear loads or power electronics. This paper provides an in-depth analysis of how harmonics affect the identification of grid impedance while using broadband measurements. Furthermore, a compensation method is proposed to remove the disturbing influences of harmonics on broadband impedance identification. This method is based on exploiting the properties of the used maximum-length binary sequence (MLBS). To explain the methodology of the proposed method, the design basis for the excitation signal is discussed in detail. The analysis from simulations and a real measurement in an industrial power grid shows the effectiveness of the proposed method in compensating the disturbing influences of harmonics on broadband impedance measurements

Power Quality Mitigation via Smart Demand-Side Management Based on a Genetic Algorithm

In modern electrical grids, the number of nonlinear grid elements and actively controlled loads is rising. Maintaining the power quality will therefore become a challenging task. This paper presents a power quality mitigation method via smart demand-side management. The mitigation method is based on a genetic algorithm guided optimization for smart operational planning of the grid elements. The algorithm inherits the possibility to solve multiple, even competing, objectives. The objective function uses and translates the fitness functions of the genetic algorithm into a minimization or maximization problem, thus narrowing down the complexity of the addressed high cardinality optimization problem. The NSGA-II algorithm is used to obtain feasible solutions for the auto optimization of the demand-side management. A simplified industrial grid with five different machines is used as a case study to showcase the minimization of the harmonic distortion to normative limits for all time steps during a day at a specific grid node, while maintaining the productivity of the underlying industrial process

Determination of the logistical and energetic flexibility potential of a logistics centre under consideration of electric mobility

Die Elektromobilität im Bereich der Nutzfahrzeuge entwickelt sich zu einem brisanten Thema in der Logistikbranche. Unbekannte Herausforderungen und Auswirkungen an den Logistikzentren und deren elektrischen Netzanschluss werden entstehen. Diese Thematik wird von der Universität Stuttgart und weiteren Projektpartnern in diesem Beitrag untersucht. Zudem werden die energetischen Herausforderungen von logistischen Komponenten betrachtet.Electric mobility in the commercial vehicle sector is developing into an explosive topic in the logistics industry. Unknown challenges and effects on logistics centres and their grid connection will arise. This topic is investigated by the University of Stuttgart and other project partners in this article. Furthermore, the energetic challenges of logistic components are considered

An A-CAES pilot installation in the distribution system: A technical study for RES integration

In the last decade in Europe, the power generated by Renewable Energy Sources (RES) has significantly increased. For the electric power system, the integration of a high amount of power generated by RES represents a big challenge. Energy Storage Systems (ESS) may help to solve problems related to the grid integration of RES. In this study, an analysis of the benefits that a planned and dedicated Adiabatic Compressed Air Energy Storage (A-CAES) system may provide to a distribution network with a high penetration of RES will be carried out. The A-CAES system, taken into account in this investigation, is based on the proposed German study so-called “ADELE project”. The technical benefits as well as the corresponding costs that A-CAES brings to the system which were analyzed using the load and RES generation time series for 2010 and 2020, and were based on technical data from a selected part of a German distribution power network, were evaluated and results of those broad investigations are presented in this study. The result of the investigations shows that the direct technical benefits are quite limited for the A-CAES technology as it exists today

Demand-Side-Management im Strommarkt: Technologiesteckbrief zur Analyse „Flexibilitätskonzepte für die Stromversorgung 2050“

Dieser Steckbrief entstand im Rahmen der Ad-hoc-Arbeitsgruppe Flexibilitätskonzepte des Akademienprojektes Energiesysteme der Zukunft (ESYS). Er dokumentiert die Ergebnisse der Fachgruppe Demand-Side-Management Strommarkt. Die Ad-hoc-Arbeitsgruppe Flexibilitätskonzepte hat analysiert, wie die Stromversorgung im Jahr 2050 mit einer CO2-Einsparung gegenüber 1990 von 80 bis 100 Prozent gestaltet werden könnte. Dabei lag der Fokus darauf, wie die Versorgungssicherheit in der Stromversorgung bei einem wachsenden Anteil volatil einspeisender erneuerbarer Energien sichergestellt werden kann. Für verschiedene Szenarien wurde untersucht, wie die fluktuierende Stromerzeugung aus Wind und Photovoltaik sinnvoll durch sogenannte Flexibilitätstechnologien - flexible Stromerzeuger, Demand-Side-Management, Speicher und Netzausbau - ergänzt werden kann. Hierbei war es das Ziel, sämtliche Möglichkeiten zur Bereitstellung von Flexibilität zu erfassen und zu charakterisieren, um deren Einsatzmöglichkeiten in unterschiedlich ausgeprägten Stromsystemen im Jahr 2050 zu identifizieren. Um eine valide und aussagekräftige Datenbasis zu erhalten, wurde ein breiter Konsultationsprozess mit Expertinnen und Experten aus Industrie und Wissenschaft durchgeführt. In zehn Fachgruppen wurden die verschiedenen Technologien zur Bereitstellung von Flexibilität analysiert und einer einheitlichen interdisziplinären Bewertung unterzogen. In diesem Technologiesteckbrief sind die Ergebnisse der Arbeitsgruppe zum Demand-Side-Management-Potential im Strommarkt zusammengetragen