| 摘要 |
PROBLEM TO BE SOLVED: To obtain a power converter in which the inductance of a DC wiring is decreased while protecting the power converter against overcurrent due to short circuit of arm by providing a current limit circuit for each phase on condition that a structure for making uniform the capacitance of unit DC capacitor for each phase is employed. SOLUTION: Each arm 21, 22, 23, 31, 32, 33 constituting a three-phase converter comprises a series connection of a plurality of GTOs required for high voltage operation. A DC smoothing capacitor 400 comprises a series parallel connection of unit capacitors 411, 412, 421, 422, 423, and the like, required for high capacity and high voltage operation. A current limit circuit 11, 12, 13 is connected between the capacitor 400 and a valve 21, 22, 23. The current limit circuit 11, 12, 13 comprises a parallel connection of a reactor and a diode. Since a corresponding current limit circuit 11, 12, 13 functions even when arm short circuit takes place in any phase of any valve, a power converter can be protected surely against overcurrent. Furthermore, wiring inductance can be minimized and made uniform for each phase of each valve 21, 22, 23. |
