The past decade has seen a rapid transformation of electric power systems in many countries worldwide through integrating renewable energy sources. However, the associated increase in irregular power generation and consumption forces system operators to compensate for resulting power fluctuations. Battery energy storage systems are predestined for integrating renewable energy sources smoothly but demand proper energy management.

Research in this area has clearly established that coordinated control is an essential contributor to the reliable operation of energy storage systems and thus the power grid. The development of battery energy storage systems requires operating strategies to efficiently manage the power flow under rapidly and continuously changing power requirements. Therefore, this work aims to identify, quantify, and evaluate the potentials and sensitivities of power flow control strategies for heterogeneous battery energy storage systems in several applications and system designs. Moreover, it aims at developing a versatile power flow control strategy for battery energy storage systems. The experimental research design was used to analyze the causal relationships between the inputs and the outputs of heterogeneous battery energy storage systems. In this context, a methodological framework was developed that includes a validated simulation model of a battery energy storage system and methods to systematically evaluate and visualize these causal relationships for different power flow control strategies and applications.

The results showed that the trade-offs between the target indicators “performance,” “efficiency,” and “service life” can be quantified accurately. Furthermore, the individual influences of the power flow control strategies and applications on the target indicators were analyzed. It was shown that, for example, a heterogeneous battery energy storage system could influence the service life of the batteries in different ways depending on the applied power flow control strategy. The findings of this work show that the applied power flow control strategy, system design, and application are essential factors to consider when operating heterogeneous battery energy storage systems.

Read more details in the published dissertation.