Control apparatus for power conversion apparatus

A power conversion apparatus comprising:

• a reactor;
• a drive switch that is turned on and off;
• a current detecting unit that detects a reactor current that flows to the reactor;
• a signal generating unit that generates a basic signal that determines a single switching period of the drive switch;
• and
• a control apparatus,
• the control apparatus comprising:
• a current control unit that includes a comparator, the comparator inverting output of the comparator when the reactor current increases to a command current, the current control unit performing peak current mode control in which the drive switch is turned off when the output of the comparator is inverted during an on-operation period determined by the basic signal;
• a switching determining unit that determines that a switching frequency of the drive switch is required to be switched when the output of the comparator is detected to have not become inverted during the single switching period while the peak current mode control is being performed;
• and
• a frequency switching unit that sets the switching frequency to a first frequency when the switching determining unit determines that the switching frequency is not required to be switched, and switches the switching frequency from the first frequency to a second frequency that is lower than the first frequency when the switching determining unit determines that the switching frequency is required to be switched.

A control method for a power conversion apparatus, the power conversion apparatus including a reactor, a drive switch that is turned on and off, a current detecting unit that detects a reactor current that flows to the reactor, and a signal generating unit that generates a basic signal that determines a single switching period of the drive switch, the control method comprising:

• performing peak current mode control in which the drive switch is turned off when output of a comparator is inverted during an on-operation period determined by the basic signal, the comparator inverting the output of the comparator when the reactor current increases to a command current;
• determining that a switching frequency of the drive switch is required to be switched when the output of the comparator is detected to have not become inverted during the single switching period while the peak current mode control is being performed;
• and
• setting the switching frequency to a first frequency when the switching determining unit determines that the switching frequency is not required to be switched, and switching the switching frequency from the first frequency to a second frequency that is lower than the first frequency when the switching determining unit determines that the switching frequency is required to be switched.