| 摘要 |
PROBLEM TO BE SOLVED: To smoothly switch two power sources to each other in a short time without causing any abrupt change in phase by providing a synchronization control circuit which synchronizes first and second power sources with the output of a second converter which converts the DC output of a first converter into an alternating current. SOLUTION: When a power source A1 is switched to another power source B2 without short break, the alternating current from the power source B2 is converted into a direct current by means of a first converter 6 and the direct current is converted into an alternating current by means of a second converter 7. The converted alternating current is operated by means of a synchronization control circuit 11 so that the current may be synchronized to the power source A1 which supplies electric power to load equipment 3. Then a third mechanical switch 9 is turned on and, at the same time, a first mechanical switch 4 is opened and power supply to the load equipment 3 is only made from the second convert 7. Therefore, independent asynchronous power sources can be switched to each other without short break and, since no abrupt change occurs in the phase and voltage, stable power supply can be made to important equipment. |
