Selective Harmonic Elimination in Multi-level Inverters with Series-Connected Transformers with Equal Power Ratings
| Autor: | Mona F. Moussa, Y.G. Dessouky |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Engineering Electric power distribution Switched-mode power supply Regulated power supply business.industry 020208 electrical & electronic engineering Electrical engineering 02 engineering and technology Voltage optimisation Distribution transformer 01 natural sciences Current transformer Control and Systems Engineering Harmonics 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Electronic engineering Power engineering Electrical and Electronic Engineering business |
| Zdroj: | Journal of Power Electronics. 16:464-472 |
| ISSN: | 1598-2092 |
| DOI: | 10.6113/jpe.2016.16.2.464 |
| Popis: | This study applies the selective harmonic elimination (SHE) technique to design and operate a regulated AC/DC/AC power supply suitable for maritime military applications and underground trains. The input is a single 50/60 Hz AC voltage, and the output is a 400 Hz regulated voltage. The switching angles for a multi-level inverter and transformer turns ratio are determined to operate with special connected transformers with equal power ratings and produce an almost sinusoidal current. As a result of its capability of directly controlling harmonics, the SHE technique is applicable to apparatus with congenital immunity to specific harmonics, such as series-connected transformers, which are specially designed to equally share the total load power. In the present work, a singlephase 50/60 Hz input source is rectified via a semi-controlled bridge rectifier to control DC voltage levels and thereby regulate the output load voltage at a constant level. The DC-rectified voltage then supplies six single-phase quazi-square H-bridge inverters, each of which supplies the primary of a single-phase transformer. The secondaries of the six transformers are connected in series. Through off-line calculation, the switching angles of the six inverters and the turns ratios of the six transformers are designed to ensure equal power distribution for the transformers. The SHE technique is also employed to eliminate the higher-order harmonics of the output voltage. A digital implementation is carried out to determine the switching angles. Theoretical results are demonstrated, and a scaled-down experimental 600 VA prototype is built to verify the validity of the proposed system. |
| Databáze: | OpenAIRE |
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