Abstract
The cascaded H-bridge (CHB) low-capacitance static compensator (LC-StatCom) has a limited operating range in the inductive region compared to a conventional StatCom due to the inherent large oscillations on the capacitor voltages. This limitation constitutes a great drawback of CHB LC-StatComs. This article presents an effective hardware-free solution to overcome this drawback. The proposed solution is based on the injection of an optimal third-harmonic circulating current to suitably shape the capacitor voltages aiming at avoiding overmodulation. Considering all the effects of the third-harmonic circulating current, the article proposes a reference design that guarantees a prescribed safe operating voltage limit, thus increasing the operational range of the LC-StatCom. The proposed approach takes into account the inherent induced oscillation on the capacitor voltages. This approach has been verified by simulation and experimentally with a laboratory prototype, corroborating the excellent performance that agrees with the theoretical analysis.
© 2021 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.
© 2021 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.
| Original language | English |
|---|---|
| Article number | 9369068 |
| Pages (from-to) | 10788-10800 |
| Journal | IEEE Transactions on Power Electronics |
| Volume | 36 |
| Issue number | 9 |
| Online published | 3 Mar 2021 |
| DOIs | |
| Publication status | Published - Sept 2021 |
| Externally published | Yes |
Funding
Manuscript received August 3, 2020; revised October 28, 2020 and January 5, 2021; accepted February 25, 2021. Date of publication March 3, 2021; date of current version June 1, 2021. This work was supported by the Singapore Ministry of Education Academic Research Fund Tier 1 under Grant 2017-T1-001-213 (RG 90/17), and in part by the NTU Start-Up Grant #000603-00001: Compact and Reliable Power Converters. Recommended for publication by Associate Editor K. Wada. (Corresponding author: Ezequiel Rodriguez.) Ezequiel Rodriguez and Josep Pou are with the School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore (e-mail: [email protected]; [email protected]).
Research Keywords
- Arm current
- capacitor voltage ripple
- cascaded H-bridge (CHB)
- circulating current control
- multilevel converter
- static compensator (StatCom)
- zero-sequence current injection