Active disturbance rejection control with cascade generalized proportional integral observer: application to the current control of grid-connected converters

关键词:  Active disturbance rejection control (ADRC) · Cascade observer · Generalized proportional integral observer (GPIO) · Periodic and non-periodic disturbances · Grid-connected converter (GcC)

Key words:  Active disturbance rejection control (ADRC) · Cascade observer · Generalized proportional integral observer (GPIO) · Periodic and non-periodic disturbances · Grid-connected converter (GcC)

摘要:

This paper presents a novel active disturbance rejection control (ADRC) scheme based on a cascade connection of generalized proportional integral observers (GPIOs) with internal models designed to estimate both polynomial and resonant disturbances. In this estimator structure, referred to as Cascade GPIO (CGPIO), the total disturbance sensitivity is the product of the sensitivities at each cascade level. This approach improves system performance against both periodic and non-periodic disturbances and enhances robustness under frequency variations in harmonic components. Additionally, the decoupled nature of the estimator reduces the order of the GPIOs, thereby simplifying tuning and limiting observer gains. The proposed control scheme is supported by a frequency-domain analysis and is experimentally validated in the current control of a grid connected converter subject to control gain uncertainties, harmonic distortion, frequency deviations, and measurement noise. Experimental results demonstrate that the CGPIO-based ADRC outperforms benchmark solutions, including proportionalintegral (PI) and proportional-resonant (PR) controllers.

Abstract:

This paper presents a novel active disturbance rejection control (ADRC) scheme based on a cascade connection of generalized proportional integral observers (GPIOs) with internal models designed to estimate both polynomial and resonant disturbances. In this estimator structure, referred to as Cascade GPIO (CGPIO), the total disturbance sensitivity is the product of the sensitivities at each cascade level. This approach improves system performance against both periodic and non-periodic disturbances and enhances robustness under frequency variations in harmonic components. Additionally, the decoupled nature of the estimator reduces the order of the GPIOs, thereby simplifying tuning and limiting observer gains. The proposed control scheme is supported by a frequency-domain analysis and is experimentally validated in the current control of a grid connected converter subject to control gain uncertainties, harmonic distortion, frequency deviations, and measurement noise. Experimental results demonstrate that the CGPIO-based ADRC outperforms benchmark solutions, including proportionalintegral (PI) and proportional-resonant (PR) controllers.