A Single-Input Space Vector for Control of AC–DC Converters Under Generalized Unbalanced Operating Conditions

This paper introduces a new technique to generate a space vector from a single real-valued signal via complex transfer functions. The single-input space vector concept may be readily integrated within conventional feedback control loops to introduce new controller functionality. In this paper, the single-input space vector is used to regulate a grid-connected ac-dc converter under generalized unbalanced conditions (i.e., grid unbalance and/or reactor unbalance). The proposed controller, based upon the single-input space vector, regulates real and reactive power while mitigating low-order harmonic voltages and currents that plague ac-dc converters under generalized unbalanced conditions. The negative feedback structure of the proposed single-input space vector controller offers high robustness, high controller bandwidth, and low controller complexity. The combination of high bandwidth and low-order harmonic ripple elimination allows significant reduction in the size and cost of the dc storage capacitor. The efficacy of the controller is proven by experimental results.