Stationary frame generalized integrators for current control of active power filters with zero steady state error for current harmonics of concern under unbalanced and distorted operation conditions

TLDR

The study proposes new integrator concepts for sinusoidal signals. The authors implement current control of active power filters by combining parallel and series PI units with stationary‑frame generalized integrators, designing PI constants, digitally realizing the integrators, and compensating computation delay. Zero steady‑state error for target current harmonics is achieved with reduced computation under unbalanced conditions, as confirmed by extensive tests on a 10 kW active‑power‑filter prototype.

Abstract

The paper proposes several concepts of integrators for sinusoidal signals. Parallel and series associations of the basic PI units using the stationary frame generalized integrators are used for current control of active power filters. Zero steady state error for the concerned current harmonics are realized, with reduced computation, under unbalanced utility or load conditions. Designing of the PI constants, digital realization of the generalized integrators, as well as compensation of the computation delay etc. are studied. Extensive test results from a 10 kW active power filter prototype are demonstrated.