| 摘要 |
A power conversion apparatus having a PWM power converter coupled to an A.C. power supply side and to a D.C. load side, a voltage controller for adjusting a D.C. output voltage from the converter, a power factor controller for adjusting a power factor on A.C. side of the converter, a command generator for generating a PWM modulation factor and a phase signal in response to the voltage and an output from the power factor controller, and a PWM modulation unit for controlling the converter in response to these command signals, comprising an enable means for allowing the power factor controller to reduce its power factor when a control parameter relating to the modulation factor of the converter approaches its limit value, and a power limit means for limiting the power of the D.C. load when a control parameter relating to the input power of the converter approaches its limit value, such that the power factor of the power converter is allowed to be reduced and the power of the D.C. load is limited respectively in each designated region, thereby preventing any overcurrent even if the power supply voltage fluctuates thereby maintaining its continuous operation, therefore, capable of reducing the capacity of the converter required for generating the same output power over the conventional converter. <IMAGE> |
