PEEMS (단국대학교 전력전자연구실)

Publication

Paper Book Patents Articles

Dongho Choi, Jiho Ju, Jeong-Yul Bang, and June-Seok Lee, "Voltage Ripple-Based Fault Diagnosis of dc-link Capacitors and Fault-Tolerant Operation via Power Regulation in Solid-State Transformer," in Proc. 2024 IECON

In Proc 2024

PEEMS

Nov. 25, 2024

views

1. Authors: Dongho Choi, Jiho Ju, Jeong-Yul Bang, and June-Seok Lee,

2. Title: Voltage Ripple-Based Fault Diagnosis of dc-link Capacitors and Fault-Tolerant Operation via Power Regulation in Solid-State Transformer

3. Published in: IECON 2024-50th Annual Congerence of the IEEE Industrial Electronics Society

4. Date of Conference: November 3-6, 2024

5. Conference Location: Chicago, LLLnois

6. Abstract

:This article proposes voltage ripple-based Fault di-agnosis of dc-link capacitors and fault-tolerant operation via power regulation in solid-state transformer (SST). An SST con-figured as an input-series-output-parallel (ISOP) structure gen-erally consists of a cascaded multilevel H-bridge (CHB) con-verter and multiple isolated DC-DC converters. In a single-phase SST based on ISOP, the dc-link of the CHB exhibits sec-ond-order voltage ripples, which are inversely proportional to the dc-link capacitance. As capacitors age, their capacitance de-creases, which is referred to as a capacitor fault. When a capac-itor fault occurs in the dc-link, the voltage ripple can exceed the rated voltage of the capacitor, necessitating fault diagnosis and tolerant operation. In this article, by tracking the maximum and minimum of the dc-link voltage, the magnitude of the voltage ripple is compared to the value from the sound condition. This method allows for the diagnosis of the capacitor fault without additional circuits. Once the fault is diagnosed, the SST transi-tions to fault-tolerant operation. In this mode, the power of the faulty module is regulated to be lower than the others by adjust-ing the modulation of the CHB. As voltage ripples are propor-tional to their corresponding module powers, the reduction of voltage ripple in the faulty module becomes feasible. The valid-ity of the proposed fault diagnosis and tolerant operation is ver-ified through experimental and simulation results, respectively.

List