Hendrik Schaede

Electric energy storages – a method for specification, design and assessment

The energy transition towards a significantly increased use of renewable energies is confronted with numerous challenges. These include the development of efficient energy storage systems, which need to address the specific requirements of the application area. The present paper contributes to this debate with the specification, design and assessment-method (SDA-method). Based on a statistical analysis of the applications load profile, the specifications for the energy storage system are defined and the design process is conducted. This is demonstrated using the example of a kinetic energy storage system. The following assessment considers the energetic behaviour, life cycle costs as well as environmental impacts. In order to fully exploit the comprehensive methodology, in-depth information is required. This relates firstly to the economical use of storages. Secondly, the multidimensional assessment is subject to many uncertainties. Our methodology reveals existing information gaps and helps to identify future research objectives.

Fault Diagnosis and State Detection in Centrifugal Pumps—A Review of Applications

This paper reviews methods and applications of fault diagnosis and state detection in centrifugal pumps. Different studies show the most common faults and their effects: Failures of mechanical seals, roller bearings, and drives as well as leakage are prevalent. Since these might lead to a stand-still of pumps, automatic fault diagnosis can improve productivity. Fault definitions, methods of fault diagnosis and state detection functionalities in centrifugal pumps as well as their categorization regarding utilized models are presented. Reviewing applications of such in centrifugal pumps shows solutions from model-free fault detection to model-based fault diagnosis. In those, impeller faults, cavitation and blockade/sedimentation receive the highest attention, while computation and sensor effort increases with method/model complexity. Two major research issues are the diagnosis of multiple fault cases and methods integrating a continuous monitoring and identification if a fault occurs.