| 摘要 |
PURPOSE:To make an apparatus applicable also to a load of three-phase star connection, from which no neutral point is pulled out, by providing high resistors composed of three-phase star connection connected in parallel with a three-phase load and having their own neutral point connected with the zero volt points of the positive and negative power sources of linear power amplifiers. CONSTITUTION:Load currents (Iu, Iv, Iw) are respectively outputted from each- phase linear power amplifiers 1, 2, 3. As resistance values of high resistors 17, 27, 37, sufficiently large values as compared with respective impedance of three-phase loads 16, 26, 36 are selected so as to realize said load currents. All residual unbalances of the total of said three-phase load currents Iu, Iv, Iw can be returned to the zero volt line of a power source via said high resistances 17, 27, 37 and a neutral point N so that almost the same load currents Iu, Iw, Iv as each-phase current command values Vu, Vv, Vw can be caused to flow through each-phase loads 16, 26, 36. |
