Modulation Signal Prediction Based Vertical Crossing Elimination for Multi-Sampled Three-Phase Grid Converters

The multisampling method is the approximation to natural sampling, which significantly reduces the control delay. However, multi-sampled grid converters suffer from the current distortion originating from the vertical crossings of the modulation and carrier signal. To handle this issue, this paper proposes an elimination method of the vertical crossings, where the modulation signal is predicted based on the current ripple information. The vertical crossing can therefore be recognized and eliminated by first-order hold (FOH) modulation. The proposed control scheme features better dynamic performance than the traditional filter-based control schemes. The effectiveness of the proposed modulator is validated by the simulation and experimental results.