New modulation strategy on raising voltage transfer ratio for matrix converts
提高矩阵变换器电压传输比的新型调制策略

Voltage transfer ratio is a key element to restrict matrix converter industrialization all the time. The concrete modulation strategy has not been put forward as yet for voltage transfer ratio to break through 0.866.A modulation strategy is put forward to make the voltage transfer ratio excess 0.866 and reach maximum 0.955 in this paper.First Its converting process was imagined into rectifying and inverting links.In rectifying process, the input current space vector modulation was adopted; while in inverting process, the space vector over-modulation mode II was applied to output voltage.Then the direct AC-AC converter was gotten by eliminating the middle direct current link.The inverting process was mainly analyzed.A concrete control algorithm was given and the voltage transfer ratio formula was deduced.Finally, simulation results show that the modulation strategy can raise the voltage transfer ratio of matrix converters, which has some theoretical research values and a good application future; but it increase harmonics. Filtering measures must be taken.