| 摘要 |
PROBLEM TO BE SOLVED: To suppress an electric cross current, by supplying power of the same phase to a winding wound on each leg of a three leg core. SOLUTION: The U-phase voltages e1u, e2u, e3u of a first to third inverters are compounded by a voltage dividing transformer, and a voltage eu is applied to the U-phase of a load 5. By the voltage eu, a current flows in the load 5, but this current has only a little harmonic component based on PWM control, and a current like a fundamental wave flows in the load 5. Concerning to the load current, a trisected current i1u, i2u, i3u flows in each winding of the voltage-dividing transformer, since the fundamental-wave components of the load 5 by the voltages e1u, e2u, e3u are equal. Accordingly, voltage drops in the windings are not generated, and they do not act as inductances to the load current, since magnetomotive forces which these windings generate are equal in magnitude and their directions are reverse to each other concerning the inside of a core, and as the result the magnetomotive forces cancel each other in the windings, and any magnetic flux by the load current is generated in the core. |
