Abstract: A converter device includes: a converter circuit unit converting alternating-current voltages from a ? connection and a Y connection of a twelve-phase rectification transformer, into a direct-current voltage; a current detection unit detecting a current of a direct-current bus connected to the converter circuit unit; an open-phase detection unit connected to a side of the ? or Y connection to detect whether open phase is caused in the connection connected thereto; and an output unit outputting, when detected that there is open phase caused in the ? or Y connection based on a detection signal of the open-phase detection unit and a current value of the direct-current bus detected by the current detection unit, an indication that open phase is caused in the ? or Y connection. When open phase is caused, it is possible to output an indication of whether the open phase is caused on the ? or Y connection side.

Abstract: A converter device includes: a converter circuit unit converting alternating-current voltages from a ? connection and a Y connection of a twelve-phase rectification transformer, into a direct-current voltage; a current detection unit detecting a current of a direct-current bus connected to the converter circuit unit; an open-phase detection unit connected to a side of the ? or Y connection to detect whether open phase is caused in the connection connected thereto; and an output unit outputting, when detected that there is open phase caused in the ? or Y connection based on a detection signal of the open-phase detection unit and a current value of the direct-current bus detected by the current detection unit, an indication that open phase is caused in the ? or Y connection. When open phase is caused, it is possible to output an indication of whether the open phase is caused on the ? or Y connection side.

Abstract: When detecting an amount of noise current generated in an inverter and flowing into a noise filter, sampling the detection values with an interval of a carrier frequency, determining whether envelope curves of respective sampled values are deemed to be constant, and in a case where the envelope curves of the sampled values are deemed to be constant, the motor control device changes the carrier frequency to another frequency that does not overlap a cutoff frequency fr of the noise filter, or to another frequency that is not close to the cutoff frequency fr of the noise filter. Due to this configuration, even when the noise filter incorporated in the motor control device is a noise filter that is manufactured without demanding any special measures to be taken to the manufacturers and is manufactured with specifications of noise filter manufacturers, a desired noise reduction effect can be obtained.

Abstract: When detecting an amount of noise current generated in an inverter and flowing into a noise filter, sampling the detection values with an interval of a carrier frequency, determining whether envelope curves of respective sampled values are deemed to be constant, and in a case where the envelope curves of the sampled values are deemed to be constant, the motor control device changes the carrier frequency to another frequency that does not overlap a cutoff frequency fr of the noise filter, or to another frequency that is not close to the cutoff frequency fr of the noise filter. Due to this configuration, even when the noise filter incorporated in the motor control device is a noise filter that is manufactured without demanding any special measures to be taken to the manufacturers and is manufactured with specifications of noise filter manufacturers, a desired noise reduction effect can be obtained.

Abstract: A noise filter includes a first substrate on which a filter input terminal, an input-side capacitor, a common-mode choke coil, and a filter output terminal are mounted and a second substrate on which an output-side capacitor and a ground capacitor are mounted. The first substrate is selected from a plurality of first substrates including a substrate in which a characteristic of at least one of an input-side capacitor and a common-mode choke coil is different, the second substrate is selected from a plurality of second substrates including a substrate in which a characteristic of at least one of an output-side capacitor and a ground capacitor is different, and the second substrate is attached to an end of the first substrate so that the filter output terminal is electrically connected to the output-side capacitor and to be substantially vertical to the first substrate.

Abstract: A noise filter includes a first substrate on which a filter input terminal, an input-side capacitor, a common-mode choke coil, and a filter output terminal are mounted and a second substrate on which an output-side capacitor and a ground capacitor are mounted. The first substrate is selected from a plurality of first substrates including a substrate in which a characteristic of at least one of an input-side capacitor and a common-mode choke coil is different, the second substrate is selected from a plurality of second substrates including a substrate in which a characteristic of at least one of an output-side capacitor and a ground capacitor is different, and the second substrate is attached to an end of the first substrate so that the filter output terminal is electrically connected to the output-side capacitor and to be substantially vertical to the first substrate.