Control of a Three-Phase Inverter under Unbalanced Grid Conditions


A control strategy for a three-phase grid connected inverter with LCL filter based on Lyapunov energy function during unbalanced grid conditions is presented in this paper. To reduce complexity and number of variables the control strategy is accomplished in a stationary two phase reference frame. Dual second-order generalized integrator structure (DSOGI) is utilized to extract the positive and negative sequence components of voltages and currents for unbalanced operation. A virtual resistor based active damping methodology based on indirect capacitor current feedback is employed to nullify the resonance oscillations due to the third order (LCL) filter. By using Lyapunov energy function based control, a direct grid current control architecture is achieved at the desired power factor.

Meeting Name

9th Annual IEEE Energy Conversion Congress and Exposition (2017: Oct. 1-5, Cincinnati, OH)


Electrical and Computer Engineering

Research Center/Lab(s)

Intelligent Systems Center

Keywords and Phrases

Electric Current Control; Electric Inverters; Energy Conversion; 3-Phase Inverter; Capacitor Current Feedback; LCL Filters; Lyapunov Energy Functions; Negative Sequence Components; Second-Order Generalized Integrators; Three-Phase Grid Connected Inverters; Unbalanced Grid; Electric Power System Control; LCL Filter; Lyapunov Energy Function; Current Control

International Standard Book Number (ISBN)

978-1509029983; 978-1509029990

Document Type

Article - Conference proceedings

Document Version


File Type





© 2017 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Oct 2017