Analysis, design and experiment of MMC based on 6500V IGCT-PLUS device

Integrated-Gate-Commutated Thyristor (IGCT) devices with the block voltage up to 6500V have been manufactured. Its application in modular multilevel converter (MMC) can significantly reduce the number of modules to optimize the converter. This paper firstly discusses the influence of increasing the rated voltage of modules on MMC characteristics such as the number of modules, dc support capacitance, weight, volume, cost, loss, harmonic. The rated parameters and component of module are designed based on IGCT-plus device of 6500V and 3800A. On this basis, the loss of the converter is analyzed by means of average equivalent method, and compared with that of MMC based on 4500V-IGCT and IEGT. Finally, both highcurrent switch-off and power-cycling running tests are carried out to verify the performance of designed module. The result shows that MMC module based on 6500V-IGCT has good stability and reliability. It has reference value for the application of IGCT with higher block voltage in MMC, thus improving power density and technical economy of MMC.