1. Control of circulating current in two parallel three-phase boost rectifiers
- Author
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Ye, Zhihong, Boroyevich, Dushan, Choi, Jae-Young, and Lee, Fred C.
- Subjects
Electric current converters ,Electric current converter ,Business ,Electronics ,Electronics and electrical industries - Abstract
One unique feature in parallel three-phase converters is a potential zero-sequence circulating current. To avoid the circulating current, most present technology uses isolation approach, such as transformers or separate power supplies. This paper proposes a parallel system where individual converters connect both ac and dc sides directly without additional passive components to reduce size and cost of the overall parallel system. In this case, the control of the circulating current becomes an important objective in the converter design. This paper 1) develops an averaged model of the parallel converters based on a phase-leg averaging technique; 2) a zero-sequence model is then developed to predict the dynamics of the zero-sequence current; 3) based on the zero-sequence model, this paper introduces a new control variable, which is associated with space-vector modulation; 4) a strong zero-sequence current control loop is designed to suppress the circulating current; 5) simulation and experimental results validate the developed model and the proposed control scheme. Index Terms--Boost rectifier, parallel three-phase converters, phase-leg, space vector modulation (SVM), variable zero-vectors, zero-sequence circulating current.
- Published
- 2002