| 摘要 |
PROBLEM TO BE SOLVED: To control exciting inrush current of a transformer connected to the output side of a power inverter. SOLUTION: An equation 1 is fulfilled where a magnetic flux of the transformer is ϕ, an initial magnetic flux is ϕ0, number of turns is N, and a voltage applied to the winding is U(t). When voltage of U(θ)=Vmsinθ is applied with the initial magnetic flux ϕ=0, the magnetic flux is expressed by an equation 2. According to the equation 2, when a phase for generating voltage is set to the time of 90 deg. or 270 deg. to a sinewave, the exciting inrush current of the transformer can be controlled. A 90 deg. or 270 deg. pulse signal is generated with a sine wave table 11, and an output voltage command is sample-held with the pulse signal with a sample-and-hold circuit 14 and multiplied by the sinewave from the table 11 with a multiplier 15, thus it is possible to generate the voltage output command voltage at 90 deg. or 270 deg. to control the power inverter. |
