Power supply system, control device, and method for measuring reactor current

A control device for controlling a boost converter that boosts direct-current power supplied from a power source, wherein

• the boost converter comprises:
• a first reactor and a second reactor connected in parallel to the power source and being able to be magnetically coupled with each other;
• a first switching element connected to one end of the first reactor that is opposite to an end of the first reactor connected to the power source;
• and
• a second switching element connected to one end of the second reactor that is opposite to an end of the second reactor connected to the power source, and wherein
• the control device comprises:
• a memory configured to store a self-inductance of the first reactor and the second reactor and a mutual inductance between the first reactor and the second reactor;
• and
• a processor configured to switch between ON and OFF of the first switching element and the second switching element alternately at a predetermined duty ratio every predetermined switching period,
• determine a present operating state of the boost converter, based on a ratio of an input voltage into the boost converter to an output voltage from the boost converter, the duty ratio, the self-inductance, and the mutual inductance, the input voltage and the output voltage being measured with a first voltmeter and a second voltmeter, respectively, and the present operating state being one of operating states among which the waveform of a reactor current flowing through the first reactor or the second reactor in the switching period differs, and
• measure an average of the reactor current in the switching period, based on the input voltage, the output voltage, and the duty ratio, in accordance with the waveform of the reactor current corresponding to the present operating state of the boost converter.

A method for measuring a reactor current in a boost converter comprising a first reactor, a second reactor, a first switching element, and a second switching element, the first reactor and the second reactor being connected in parallel to a power source supplying a direct-current power and being able to be magnetically coupled with each other, the first switching element being connected to one end of the first reactor that is opposite to an end of the first reactor connected to the power source, the second switching element being connected to one end of the second reactor that is opposite to an end of the second reactor connected to the power source, the reactor current flowing through the first reactor or the second reactor, the method comprising:

• obtaining a value of an input voltage inputted into the boost converter, the value being measured with a first voltmeter;
• obtaining a value of an output voltage outputted from the boost converter, the value being measured with a second voltmeter;
• determining a present operating state of the boost converter, based on a ratio of the input voltage to the output voltage, a predetermined duty ratio, a self-inductance of the first reactor and the second reactor, and a mutual inductance between the first reactor and the second reactor, wherein ON and OFF of the first switching element and the second switching element are switched alternately at the duty ratio during a predetermined switching period, and the present operating state is one of operating states among which the waveform of the reactor current in the switching period differs;
• and
• measuring an average of the reactor current in the switching period, based on the input voltage, the output voltage, and the duty ratio, in accordance with the waveform of the reactor current corresponding to the present operating state of the boost converter.