Performance enhancement of a modified filtration based control scheme for hybrid energy storage system in low voltage direct current microgrid

Energy storage devices (ESDs) has become essential components of microgrid to mitigate voltage/current fluctuations arising due to the intermittent nature of distributed renewable energy sources (DRESs) and unpredictable load demand. However, sole ESD is incapable of meeting the multifaceted exigencies such as higher power and energy density, lesser cost, longer life cycle, and faster dynamic response within a microgrid. Therefore, complementary characteristic ESDs (most commonly battery and supercapacitor (SC)) are hybridized to maximize reliability, stability and dependability of the microgrid. This paper proposes a new filtration-based control strategy for effectively distributing power between the battery and SC while maintaining a stable DC grid voltage. The control approach diverts the error component of the battery current and the DC bus voltage error to the SC current controller in addition to the supply of transient power. This added functionality enhances DC bus voltage regulation capability and alleviates the strain on batteries, ultimately extending the operating lifespan. Moreover, a comparative performance evaluation of suggested control scheme with respect to existing methods is carried out. The performance metrics are found better under different loading scenarios justifying the effectiveness of new filtration-based method in a microgrid equipped with hybrid energy storage unit.