| 摘要 |
PROBLEM TO BE SOLVED: To provide an AC-AC direct conversion equipment at low cost in which a power supply short-circuit is prevented by avoiding the overlap between commutation period and an arm switching signal of an AC switch, and it is possible to design an electric current rating at a necessary and sufficient value of semiconductor switching elements. SOLUTION: In an AC-AC direct conversion equipment, AC switches capable of controlling bidirectional electric currents are connected between respective phase output terminals of a three-phase AC power supply, respectively, and AC voltages with arbitrary magnitude and frequency are obtained by switching these AC switches. The AC-AC direct conversion equipment includes means 10 for determining magnitude correlation for determining a magnitude correlation of respective phase voltages of three-phase AC power supply, and outputting an arm switching signal to switch the arm to be switched of the conversion equipment depending on the magnitude correlation; and PLL means 20 and carrier generating means 30 for synchronizing peak timing of carrier to be compared with voltage command of the conversion equipment for switching the AC switches with the arm switching signal. COPYRIGHT: (C)2007,JPO&INPIT
|
