Three-Phase Voltage Reconstruction With Optimal Time Insertion in Current Source Rectifiers Using a Single Voltage Sensor

This article proposes a single-sensor grid voltage measurement method for a three-phase current source rectifier (3ph-CSR). In a 3ph-CSR, the voltage applied to the output filter varies with the switching state, and the grid line-to-line voltage is directly applied to it. Leveraging this characteristic, the proposed method utilizes a single sensor to measure the grid voltage. However, inherent limitations in the measuring circuit and the digital signal processor (DSP) cause measurement delays during voltage sensing, leading to unmeasurable regions in the grid voltage. To address this limitation, this article introduces an optimal vector injection pulse width modulation (OVI-PWM) method that overcomes unmeasurable. Furthermore, if the grid voltage is unknown during the start-up sequence, it is impossible to limit the inrush current. To mitigate these challenges, a start-up sequence is designed to limit inrush current and enable accurate grid voltage sensing. The proposed single-sensor voltage reconstruction and start-up sequence are validated through simulations and experiments using a 750 W prototype. The results confirm the effectiveness of the proposed approach in achieving accurate voltage measurement and stable operation.