Control Design of a PFC With Harmonic Mitigation Function for Small Hybrid AC/DC Buildings

Unprecedented expansion of native dc powered equipment (LEDs, computers, and consumer electronics) has increased commercial and residential dc electricity usage over the past decade. Thus, it is foreseeable that hybrid ac/dc buildings featuring both ac and dc infrastructures will coexist. A hybrid ac/dc building will involve an efficient centralized rectifier that supplies all the dc loads, while legacy ac loads will remain connected to the existing ac infrastructure. This paper explores the opportunity of harmonic mitigation at distribution level in small hybrid ac/dc building by using a centralized power factor corrector (PFC) with large bandwidth. The current reference generator for the harmonic mitigation function (HMF) is explained along with power considerations. The PFC uses a proportional resonant controller, instead of a PI controller, without requiring additional sensors in the rectifier. A computationally inexpensive implementation of the phase-locked loop is also proposed along with considerations on parameter selection. The proposals provide all the steps for the straightforward control design of the PFC+HMF with fast calculations. The HMF requires only software modifications in the PFC and one sensor to measure the nonlinear load. Simulation and experiments validate the proposed procedures.