Abstract: A motor controller includes a plurality of inverters that supply power to a corresponding motor of a plurality of motors through pulse width modulation control, a direct current power supply that supplies power to the plurality of inverters, and a capacitor connected parallel to the direct current power supply. Each of the plurality of inverters is categorized into one of a plurality of groups based on a switching frequency. All inverters in each of the groups have corresponding carrier signals being triangular wave signals determined based on a reference frequency assigned to the group. At least one of the triangular wave signals has at least one of a frequency or a phase different from a frequency or a phase of another triangular wave signal of the triangular wave signals.

Abstract: A design assist device assists with designing of a power supply system to supply and distribute power from a power supply and a capacitor connected parallel to each other to a plurality of load devices through a power supply path combining a plurality of power cables. The design assist device includes a calculator and an outputter. The calculator calculates time-series data about a current flowing through the capacitor based on configuration information representing an overall configuration of the power supply path and operation pattern information representing an operation pattern of each of the plurality of load devices, and calculates, based on the time-series data about the current, a recommended capacitance being a capacitance recommended for the capacitor. The outputter outputs at least information about the recommended capacitance for the capacitor.

Abstract: A power supply control device according to one or more embodiments may be provided to: control a power conversion device that has a configuration in which a resonant circuit is provided on an output side of a matrix converter including switching circuits having snubber elements, and that performs AC-AC conversion of output from a multi-phase AC power supply. The power supply control device performs control such that: the output current, which has a phase difference caused by the resonant circuit, is negative during a period in which an absolute value of a positive-going output voltage that is output from the power conversion device increases while the output current is positive during a period in which the absolute value of a negative-going output voltage increases; and a polarity of the output current does not change within a period in which the snubber element is discharged.

Abstract: A power supply control device according to one or more embodiments may be provided, in which a power conversion device has a configuration in which a resonant circuit is provided on an output side of a matrix converter using switching circuits including snubber elements so as to perform AC-AC conversion of output from a multi-phase AC power supply. The power conversion device is controlled to make an amplitude of an output current, a phase of the output current and an instantaneous reactive power as close to a control target as possible. The amplitude and the phase of the output current and the instantaneous reactive power are derived based on: an input voltage and a phase of a multi-phase current input to the power conversion device; and characteristics of the resonant circuit.

Abstract: A power supply control device according to one or more embodiments may be provided, in which a power conversion device has a configuration in which a resonant circuit is provided on an output side of a matrix converter using switching circuits including snubber elements so as to perform AC-AC conversion of output from a multi-phase AC power supply. The power conversion device is controlled to make an amplitude of an output current, a phase of the output current and an instantaneous reactive power as close to a control target as possible. The amplitude and the phase of the output current and the instantaneous reactive power are derived based on: an input voltage and a phase of a multi-phase current input to the power conversion device; and characteristics of the resonant circuit.

Abstract: A power supply control device according to one or more embodiments may be provided to: control a power conversion device that has a configuration in which a resonant circuit is provided on an output side of a matrix converter including switching circuits having snubber elements, and that performs AC-AC conversion of output from a multi-phase AC power supply. The power supply control device performs control such that: the output current, which has a phase difference caused by the resonant circuit, is negative during a period in which an absolute value of a positive-going output voltage that is output from the power conversion device increases while the output current is positive during a period in which the absolute value of a negative-going output voltage increases; and a polarity of the output current does not change within a period in which the snubber element is discharged.

Abstract: There is provided a non-contact voltage measurement device which can precisely measure a measurement target voltage by suppressing a flow of a leakage current via a parasitic capacitance produced between an electric field shield and an electric circuit. A drive voltage applying unit applies a voltage generated from an output voltage of a low impedance unit of the electric circuit and equal to an input voltage of a high impedance unit, to a first electric field shield coated on the high impedance unit.

Abstract: Provided is a non-contact voltage measuring device capable of measuring, with given accuracy, measurement target voltages applied to various conducting wires having respective different shapes. An inner electrode which is deformable depending on a shape of a wire “w” is electrically connected, via a connecting section, to an outer electrode fixed to an electric field shield.

Abstract: A measuring apparatus has a physical amount transformer that transforms a physical amount into a current, a measuring circuit that measures an output current of the physical amount transformer, a power supply circuit that inputs an output of the measuring circuit, a circuit switching unit that switches between a first state and a second state, the first state constituting a circuit inputting the output of the measuring circuit into the power supply circuit, the second state constituting a circuit directly inputting the output of the measuring circuit into the physical amount transformer, and a switching controller driven by the power supply circuit to control the circuit switching unit.

Abstract: A measurement device has a sensor that generates current by electromagnetic coupling to a power line, a measurement circuit that measures one of voltage and power, the voltage and the power being obtained by the current generated in the sensor according to voltage at the power line, a conductive member electrically connected to a signal ground line of the measurement circuit, and an insulating member that brings the conductive member close to an external conductor and insulates the conductive member from the external conductor.

Abstract: Provided is a non-contact voltage measuring device capable of measuring, with given accuracy, measurement target voltages applied to various conducting wires having respective different shapes. An inner electrode which is deformable depending on a shape of a wire “w” is electrically connected, via a connecting section, to an outer electrode fixed to an electric field shield.

Abstract: There is provided a non-contact voltage measurement device which can precisely measure a measurement target voltage by suppressing a flow of a leakage current via a parasitic capacitance produced between an electric field shield and an electric circuit. A drive voltage applying unit applies a voltage generated from an output voltage of a low impedance unit of the electric circuit and equal to an input voltage of a high impedance unit, to a first electric field shield coated on the high impedance unit.

Abstract: A measuring apparatus has a physical amount transformer that transforms a physical amount into a current, a measuring circuit that measures an output current of the physical amount transformer, a power supply circuit that inputs an output of the measuring circuit, a circuit switching unit that switches between a first state and a second state, the first state constituting a circuit inputting the output of the measuring circuit into the power supply circuit, the second state constituting a circuit directly inputting the output of the measuring circuit into the physical amount transformer, and a switching controller driven by the power supply circuit to control the circuit switching unit.

Abstract: A measurement device has a sensor that generates current by electromagnetic coupling to a power line, a measurement circuit that measures one of voltage and power, the voltage and the power being obtained by the current generated in the sensor according to voltage at the power line, a conductive member electrically connected to a signal ground line of the measurement circuit, and an insulating member that brings the conductive member close to an external conductor and to insulates the conductive member from the external conductor.