| 摘要 |
PROBLEM TO BE SOLVED: To improve the power conversion efficiency when AC power is normal and the transient response of AC output during stoppage of AC power, by validating a current control command when the AC power is normal, and increasing the response speed of control when the stoppage of AC power is detected. SOLUTION: When AC power 1 is normal, the cooperative operation side of an operation switch 11 is selected, and besides the frequency of a carrier generator 18 is selected. Then, a PWM signal long in control cycle is outputted from a PWM controller 17, and the response speed of a power converter 4 gets in low-speed condition. Moreover, if AC power 1 stops, and a power stoppage signal is outputted from a power stoppage detector 12, AC power 1 is paralleled off, and the operation switch 11 changes from cooperative operation side over to independent operation side, and the carrier generator 18 is switched from low-speed side to high-speed side. Then, a PWM signal short in control cycle is given from the PWM controller 17, and the control response speed of the power converter 4 gets in high-speed condition. |
