Online Identification of Lithium-Ion Battery Parameters Using Recursive Least Squares for an Enhanced Static Compensator

Identifying dynamic parameters in lithium-ion batteries is of paramount importance for estimating state-of-charge and state-of-health. An enhanced-STATCOM (E-STATCOM), that is a STATCOM that integrates energy storage, can incorporate battery-parameter identification algorithms without compromising its normal operation. The paper presents a design of an E-STATCOM that ensures that the current harmonics injected into the battery for parameter identification do not alter the grid current. Using the injected current values and the corresponding battery voltage values, a Recursive Least Squares algorithm provides the battery parameters. Thus, the paper describes the E-STATCOM architecture and the proposed control that seamlessly integrates online battery-parameter identification, as well as the validation of the proposed approach.