Two-stage Four-legged Matrix Converter Modeling And Control

The two-stage of four-leg matrix converter with a new topological structure of the matrix converter is based on the three-phase transformation AC-DC-AC two-stage structure, not only in terms of their functions with a two-way flow of energy, sinusoidal input and output current, and controllable input power factor, without intermediate capacitance but also having the ability to handle load imbalance. It is a potential matrix converter with good prospect.The paper proposes a 3-D space vector modulation strategy and another strategy based on the carrier modulation strategy oriented the two-stage matrix converter. The strategy is simple and effective, especially for the high-dimensional modulation field. At last a random carrier modulation method based on the Markov chain effectively reduce the current harmonic components, while reducing electromagnetic interference.At first we focus our attention on modeling, and make use of state-space averaging to get a large signal model of four legs of two-stage matrix converter. The Analysis of unbalanced load on the matrix converter input current are presented. Based on the previous model, we design an advanced decoupling controller on synchronous rotating coordinate system based on observation of adaptive disturbance. We not only prove the stability of close-loop system based on Lyapunov stability theory, but also analyses the robustness of the given control law.We design four legs of two-stage matrix converter system based on repeat controller. It is a simple and effective way of handling the load imbalance problem. The text from the frequency domain and time domain gives the system stability criterion, which is a general design steps, and it will contribute to the controller design in the other areas .