Abstract
This paper presents a generalized pulse width modulation (PWM)-based control algorithm for multiphase neutral-point-clamped (NPC) converters. The proposed algorithm provides a zero sequence to be added to the reference voltages that contributes to improve the performance of the converter by: 1) Regulating the neutral-point (NP) current to eliminate/attenuate the low-frequency NP voltage ripples; 2) reducing the switching losses of the power semiconductors; and 3) maximizing the range of modulation indices for linear operation mode. The control method is formulated following a carrier-based PWM approach. Hence, dealing with complex space-vector diagrams to solve the modulation problem for multiphase converters is avoided. The recursive approach means that it can be easily extended to n-phase converters without increasing the complexity and computational burden, making it especially attractive for digital implementation. The proposed method allows regulating the NP voltage without the need for external controllers; therefore, no parameter tuning is required. The algorithm has been tested in a four-leg NPC converter prototype performing as a three- and four-phase system and operating with balanced and unbalanced loads.
| Original language | English |
|---|---|
| Article number | 7542559 |
| Pages (from-to) | 4878-4890 |
| Number of pages | 13 |
| Journal | IEEE Transactions on Power Electronics |
| Volume | 32 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jun 2017 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2016 IEEE.
ASJC Scopus Subject Areas
- Electrical and Electronic Engineering
Keywords
- capacitor voltage balance
- Carrier-based pulse-width modulation
- multiphase multilevel converter
- neutral-point-clamped (NPC) converter