The Three Vector Model Predictive Direct Power Control of Grid-Connected Inverter

Distributed generation can operate independently or in grid connected. However, in order to realize the efficient utilization of distributed generation, it is generally connected to the grid. Converter is one of the main ways for distributed generation to connect to power grid. This paper discusses the control strategy of grid connected inverter. The dual-vector model predictive direct power control for grid-connected inverter improves the fixed output voltage vector, high grid-side current distortion rate, large reactive power pulsation and other problems when the single-vector model predictive direct power control is adopted. However, the two-vector model predicts that the amplitude of the output vector cannot be adjusted when the two vectors are both effective, and the active power pulsation is still large when only the reactive power is controlled by the deadbeat control. Aiming at these deficiencies, on the basis of its proposed a grid inverter three vector model to predict the direct power control strategy, the control strategy will be two effective voltage vector and a zero voltage vector in a control cycle, makes the output vector direction and amplitude are adjustable, and the active and reactive power no beat control way of vector function to calculate the time, The control precision is further improved. The simulation and experimental results show that compared with the direct power control predicted by the single vector model and the double vector model, the direct power control predicted by the three vector model for the grid-connected inverter has lower current harmonic content, smaller power pulsation and stronger robustness.