| 摘要 |
PURPOSE:To cut down the cost, to improve conversion efficiency and to enhance reliability, by getting three-phase power by means of the V-connection between a single-phase inverter and a single-phase transformer. CONSTITUTION:The single-phase power of a single-phase power source 1 is delivered as DC power not only through a single-phase transformer 2 but also through a single-phase rectifier (a power rectifier) 3. the output of this rectifier is converted into single-phase AC by a single-phase inverter 4 and is delivered by the phase difference of 120 deg. from the output of the above-mentioned transformer 2. After the V-connection is made with the output winding of the single- phase transformer 2 through a filter 5, the output of the rectifier is supplied to a three-phase induction motor of a load 6 as the threephase power. The control circuit of the inverter 4 is composed of a phase detection circuit 7, a phase control amplifier 9, a voltage control oscillator 11, etc. From the deviation between voltage detection signals V1 and V2 the inverter 4 is controlled. The output of the inverter 4 is thereby controlled against the output of the transformer 2 equipotentially with the phase difference of 120 deg. so that the three- phase output can be obtained.
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