Improved rule-based power distribution algorithm for hybrid battery storage systems and real-world validation

Journal of Energy Storage, vol. 86, pp. 111360

Abstract

Large-scale battery energy storage systems (BESS) can serve many applications and are already widely used for grid services. The rapidly growing BESS market and the recent interest in their deployment accentuate the need for safe, reliable, and highly available energy management systems (EMS) for automated control. However, the EMS and their integrated power distribution algorithms (PDA) can still be optimized to adapt various characteristics of the BESS. This study investigates a new version of a PDA with a particular focus on battery aging and system efficiency. The rule-based PDA has been validated on a 6 MW/7.5 MWh BESS system with five battery technologies providing frequency containment reserve to the German power grid. The results underline the PDA's capability to exploit the individual strengths of each battery technology. The PDA sets objectives for the state of charge, energy throughput, and power of the batteries to extend battery life. The distribution of energy throughputs among batteries can be selected in advance through the new implementation of the PDA. At the same time, the inverters are significantly less often activated and used in the optimal efficiency range, increasing the overall system efficiency to approximately 82 %. The optimized switching behavior leads to less frequent power switching between individual battery units and longer phases with more constant power. In addition, the operational efficiency of BESS can be improved by the choice of battery technology and the overall system layout on the hardware side. The improvements on the software side are only possible by increasing the overall power requests through multi-use operation by about 6 % compared to our benchmark test. The results can be used by BESS operators to increase operational profits due to longer battery life and fewer efficiency losses.

Authors 5

1. Lucas Koltermann corresponding Aachen Institute for Power Electronics and Electrical Drives (ISEA) Institute for Power Generation and Storage Systems (PGS)

   Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, 52074 Aachen, Germany

   Institute for Power Generation and Storage Systems (PGS), E.ON ERC, RWTH Aachen University, 52074 Aachen, Germany

   Jülich Aachen Research Alliance, JARA-Energy, 52056 Aachen, 52425 Jülich, Germany

2. Mauricio Celi Cortés Aachen Institute for Power Electronics and Electrical Drives (ISEA) Institute for Power Generation and Storage Systems (PGS)

   Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, 52074 Aachen, Germany

   Institute for Power Generation and Storage Systems (PGS), E.ON ERC, RWTH Aachen University, 52074 Aachen, Germany

   Jülich Aachen Research Alliance, JARA-Energy, 52056 Aachen, 52425 Jülich, Germany

3. Jan Figgener Aachen Institute for Power Electronics and Electrical Drives (ISEA) Institute for Power Generation and Storage Systems (PGS)

   Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, 52074 Aachen, Germany

   Institute for Power Generation and Storage Systems (PGS), E.ON ERC, RWTH Aachen University, 52074 Aachen, Germany

   Jülich Aachen Research Alliance, JARA-Energy, 52056 Aachen, 52425 Jülich, Germany

4. Sebastian Zurmühlen Aachen Institute for Power Electronics and Electrical Drives (ISEA) Institute for Power Generation and Storage Systems (PGS)

   Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, 52074 Aachen, Germany

   Institute for Power Generation and Storage Systems (PGS), E.ON ERC, RWTH Aachen University, 52074 Aachen, Germany

   Jülich Aachen Research Alliance, JARA-Energy, 52056 Aachen, 52425 Jülich, Germany

5. Dirk Uwe Sauer Aachen Institute for Power Electronics and Electrical Drives (ISEA) Institute for Power Generation and Storage Systems (PGS)

   Forschungszentrum Jülich · Helmholtz-Institute Münster · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research Helmholtz-Institute Münster: Ionics in Energy Storage (IEK-12), 52425 Jülich, Germany

   Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, 52074 Aachen, Germany

   Institute for Power Generation and Storage Systems (PGS), E.ON ERC, RWTH Aachen University, 52074 Aachen, Germany

   Jülich Aachen Research Alliance, JARA-Energy, 52056 Aachen, 52425 Jülich, Germany