Data-Driven SoH Estimation-Based Rotational Equalization for Battery Lifecycle Extension in CHB Systems


Çakiraslan E. N., Ünal S., TEKGÜN B., BOYNUEĞRİ A. R.

8th Global Power, Energy and Communication Conference, GPECOM 2026, Naples, Italy, 3 - 05 June 2026, pp.195-200, (Full Text)

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1109/gpecom70462.2026.11578740
  • City: Naples
  • Country: Italy
  • Page Numbers: pp.195-200
  • Keywords: battery aging, cascaded H-bridge, data-driven model, SoH estimation
  • Yıldız Technical University Affiliated: Yes

Abstract

Cascaded H-Bridge (CHB) systems are distinguished by their modular architecture, facilitating integration into Battery Energy Storage Systems (BESS); however, conventional Level-Shifted Pulse Width Modulation (LS-PWM) in these systems causes unequal module utilization. Modules assigned to lower-level carriers experience longer activation durations, leading to asymmetric battery aging and a significantly reduced battery module lifecycle. To address this critical limitation, this study proposes a novel State-of-Health (SoH)-based dynamic rotational equalization strategy integrated with a Gaussian Process Regression (GPR) estimation framework for a 7-level CHB inverter. The proposed strategy continuously tracks each module's estimated SoH. By dynamically rotating the carrier-wave hierarchy, the system adjusts the power consumption per battery module according to its current capacity. Simulation results validate that the proposed approach successfully eliminates the 75% power imbalance typical of fixed-carrier techniques. Under asymmetric aging conditions (varying from 1.6 Ah to 2.0 Ah capacity), the load is adaptively distributed: the lowest-capacity module's consumption is restricted to 0.3 Ah, while high-SoH modules handle 0.4 Ah. Furthermore, this dynamic active balancing is achieved while maintaining purely sinusoidal output voltage and current waveforms.