Optimal load discharge of a capacitive energy storage device

Document Type

Conference Proceeding

Publication Date



Department of Mechanical Engineering-Engineering Mechanics


This paper proposes a novel concept of optimizing the load profile for a given capacitive energy storage system using a Lyapunov based closed loop controller where the objective is to balance energy and power usage of a load. The energy storage source is modeled as a capacitor for simplicity to explore the theoretical and practical implications of the developed technique. After illustrating the control law experimentally, simulation and experimental results are presented to extrapolate its use to other conditions. Experimentally, the load is implemented with a controllable load instrument. Weights are used to emphasize different features of the optimal control law's objective. When the objective is focused towards minimizing load voltage, the control law results in a simple, exponential discharge of the storage energy. In contrast, when load power is the objective, the majority of the storage energy is extracted in an initial pulse with a higher loss of energy through the system's parasitic resistance. These two behaviors allow for a shaping of the storage power through closed loop load scheduling. Results show that the optimal discharge shape approaches that of a pulse load, and is applicable to pulse load applications such as rail guns and radar on electric naval ships.

Publisher's Statement

©2019 IEEE. Publisher’s version of record: https://doi.org/10.1109/COMPEL.2019.8769632

Publication Title

2019 20th Workshop on Control and Modeling for Power Electronics (COMPEL)