Patent ID: 8847442

Claim:
A power converting system comprising: a first power converting apparatus configured to convert an input power supplied via a power supply line into a first drive power and supply the first drive power to a first control target to drive the first control target; and a second power converting apparatus configured to convert the input power supplied via the power supply line into a second drive power and supply the second drive power to a second control target to drive the second control target, wherein the first power converting apparatus and the second power converting apparatus are connected with each other via the power supply line and an earth line, wherein the first power converting apparatus includes: a first carrier-signal generating unit configured to select, depending on first information to be transmitted to the second power converting apparatus, a first frequency from a plurality of first candidate frequencies or a first candidate frequency range and generate a first carrier signal having the selected first frequency; a first PWM-signal generating unit configured to generate a first PWM signal using the generated first carrier signal; and a first switching element connected to the power supply line and configured to perform switching according to the generated first PWM signal to convert the supplied input power into the first drive power, wherein a first voltage-to-earth signal corresponding to the selected first frequency depending on the first information is transmitted to the second power converting apparatus via the power supply line and the earth line, and wherein the second power converting apparatus includes: a second detecting unit configured to detect the first voltage-to-earth signal via the power supply line and the earth line; a second extracting unit configured to extract a component of the first frequency from the detected first voltage-to-earth signal; and a second restoring unit configured to restore the first information based on the extracted component of the first frequency.