Han Hua

A simple current control strategy for four-leg direct Matrix converter

A four-leg Matrix converter is built based on conventional Matrix converter. It is required to provide a path for the zero-sequence load current when the added midline bridge connects the neutral point of load. In this paper, a model predictive control method for a four-leg matrix converter under unbalanced load condition is described. The predictive control method is based on the optimal selection among the valid switching states of the converter by evaluating a cost function. Compared with the conventional method, the predictive control method is simple to implement without coordination transformation and duty ratio calculation. To support the theoretical analysis, the feasibility and reliability of the proposed method are verified by simulation results.

An open circuit fault-tolerant control strategy for matrix convertor based on mathematical construction modulation

Matrix convertor is a direct AC/AC converter with many advantages. However, it could heavily impact the operation performance and the use of life when having open circuit fault. Hence, proposing an open circuit fault tolerant control strategy for matrix convertor based on mathematical construction modulation. First, using output observer detects and diagnoses the open circuit faults; then, taking the hardware method of adding a redundant phase bridge to replace the fault phase when open circuit fault occurs, at the same time, modifying the modulation strategy for the continuous operation and good dynamic and steady performance even under fault condition. The simulation results verify the feasibility and availability of the method proposed.