Abstract
This article deals with the control problem of injecting balanced grid currents from a grid-tied photovoltaic cascaded H-bridge (CHB) inverter under severe interphase power imbalances. Existing solutions are hindered by the additional harmonic content required at the inverter output voltages. Therefore, a mathematical formulation for which the solution has minimal harmonic content is proposed. The proposed solution, optimal common-mode voltage (OCMV), has an analytical form that allows deducing and analyzing the CHB operating area. The real-time implementation of the OCMV requires solving a nonlinear two-variables system; thus, an iterative and distributed algorithm is designed. By doing so, the proposed OCMV can be fully formulated and implemented using a real-time control platform. The experimental validation was carried out in a scale-down 3 kW grid-tied seven-level CHB inverter governed by phase-shifted model predictive control. The laboratory results show that the proposed OCMV allows obtaining symmetrical grid currents while maintaining low-distorted inverter output voltages.
| Original language | English |
|---|---|
| Pages (from-to) | 11366-11376 |
| Number of pages | 11 |
| Journal | IEEE Transactions on Industrial Electronics |
| Volume | 71 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 2023 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Keywords
- Cascaded H-bridge (CHB) inverter
- Harmonic analysis
- interphase power imbalance
- Inverters
- Mathematical models
- optimal control
- phase-shifted model predictive control (PS-MPC)
- Power system harmonics
- Real-time systems
- Voltage
- Voltage control
- zero-sequence voltage (ZSV)
