A Linearized Time-Invariant Voltage-Sensorless Direct Power Control for Three-Phase Vienna Rectifiers

In this paper, a linearized time-invariant voltage-sensorless direct power control (DPC) with balanced and unbalanced dc-link voltage is proposed in a three-phase Vienna rectifier. To achieve voltage sensorless with unbalanced dc-link voltage, the control architecture consists of three sub-architectures, including 1) linear time-invariant direct power control; 2) virtual flux, input active power and reactive power estimators; 3) zero crossing distortion and capacitor voltage unbalance compensations under single carrier pulse-width modulation (PWM) operation. The proposed method transfers the system from linear time-varying system to linear time-invariant system by algebraic transformation, which makes the design of the controller more directly. The proposed direct power control method can reduce system cost and lower input current total harmonic distortion and does not require the use of phase-locked loop (PLL). A 2.4kW prototype is constructed and some simulation and experimental results are offered to verify the validity of the proposed method.