Phase-Shifted Modulation Strategy for Voltage Balancing in Neutral-Point Clamped Converter


This paper suggests a new method to balance the voltage of the two capacitors in the three-level neutral-point clamped (NPC) converter. The proposed method only needs the information of two capacitor voltages. The two capacitor voltages are fed back to the controller and then the controller generates phase shifting value with which sinusoidal modulation will be adjusted to the left or right. This method has upper and lower modulation signals. The outcome of the closed-loop is a phase compensation which will be applied to the upper and lower modulation signals. By applying the phase compensation in a different direction on the two modulation signals, this method provides voltage balancing. The new voltage balancing technique is verified by simulation and experimental results.

Meeting Name

29th Annual IEEE Applied Power Electronics Conference and Exposition (2014: Mar. 16-20, Fort Worth, TX)


Electrical and Computer Engineering

Keywords and Phrases

Capacitors; Phase Shift; Power Electronics; Capacitor Voltages; Modulation Signals; Modulation Strategy; Neutral Point Clamped; Neutral-Point Clamped Converters; Phase Compensation; Sinusoidal Modulation; Voltage Balancing; Modulation; Phase Modulation; Topology; Space Vector Pulse Width Modulation; Switching Frequency; Voltage Control; Closed Loop Systems; Feedback; Power Capacitors; PWM Power Convertors

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


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© 2014 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Mar 2014