| 摘要 |
<p>Provided is an uninterruptible variable voltage device capable of varying voltage uninterruptibly and continuously or uninterruptibly in multistage by preventing spark from occurring upon startup or operation change and capable of, for example, correcting voltage drop due to the startup of a large capacity motor, the temperature adjustment of an electric heater furnace, and the increase and decrease of the load in a distribution line by preventing the situations such as wasteful energy consumption and the difficulty in the control of electric motor startup current. A main coil comprises an intermediate tap connected to a load driven by a three-phase power supply and is provided for each phase of the three-phase power supply while having one terminal connected through a first switch to one phase of the three-phase power supply and the other terminal connected to the neutral of the three-phase power supply. A current control means is connected in parallel between the intermediate tap of the mail coil and the first switch and controls the flowing current to control the current flowing between the intermediate tap and the first switch. A control circuit controls the current control means. Using the main coil, the current control means, and the control circuit, the current flowing between the intermediate tap and the first switch is controlled.</p> |
