Converter circuit and motor drive control device equipped with a converter circuit, air conditioner, refrigerator, and induction heating cooker

摘要

A converter circuit, which includes: a rectifier (2) configured to rectify an AC voltage; a first converter section (3a) that is connected to the output of said rectifier (2) and that has a first reactor (4a), a first switching element (5a) and a first reverse current protection element (6a) ; a second converter section (3b) that is connected to the output of said rectifier (2), which has a second reactor (4b), a second switching element (5b) and a second reverse current protection element (6b) and that it is connected to said first parallel converter section; switching control means (7) configured to control said first and second switching elements; and a filtering capacitor (8) that is provided at the output of said first and second converter sections, characterized in that current detection means (20) configured to detect the input current introduced to said first and second are also provided. converter sections and output power detection means (30) configured to detect the output power of said first and second converter sections and why said switching control means (7) are configured to obtain a circuit based efficiency in said input current and said output power and to switch the current mode of the current flowing through said first and second reactors to either a continuous mode, a critical mode or a discontinuous mode based on the efficiency of the circuit.