Abstract: A power conversion system comprises: a plurality of power conversion devices; and a master controller capable of communicating with the plurality of power conversion devices by a serial communication channel. The master controller transmits the same control command to the plurality of power conversion devices by serial communication via the serial communication channel, and the plurality of power conversion devices each perform power conversion from the primary side to the secondary side on the basis of the same control command.

Abstract: An LED indicator 4 connected to industrial machinery including an inverter 1, includes: an LED substrate 8 into which a display control signal according to a state relating to the industrial machinery is input; and a plurality of displays 31, 32, and 33 configured to display in a lighting state corresponding to a state of the industrial machinery, on the basis of the display control signal input by the LED substrate 8. The plurality of displays 31, 32, and 33 each include a partially circular-arc shape, and are generally arranged in an approximately annular shape. The plurality of displays 31, 32, and 33 include the two displays 31, 32 that generally configure a half ring at one side of the approximately annular shape, and the one display 33 that generally configures a half ring at the other side of the approximately annular shape.

Abstract: An electric motor drive control system includes an electric motor drive control device, a manual command device connected to the electric motor drive control device, a radio that performs radio communication with a telecommunication device that is a radio connection destination, and processing circuitry that sets a radio communication mode in which the radio responds to a radio connection request from the telecommunication device to establish a radio connection, the radio communication mode being set when the manual command device issues no manual command.

Abstract: An LED indicator 4 connected to industrial machinery including an inverter 1, includes: an LED substrate 8 into which a display control signal according to a state relating to the industrial machinery is input; and a plurality of displays 31, 32, and 33 configured to display in a lighting state corresponding to a state of the industrial machinery, on the basis of the display control signal input by the LED substrate 8. The plurality of displays 31, 32, and 33 each include a partially circular-arc shape, and are generally arranged in an approximately annular shape. The plurality of displays 31, 32, and 33 include the two displays 31, 32 that generally configure a half ring at one side of the approximately annular shape, and the one display 33 that generally configures a half ring at the other side of the approximately annular shape.

Abstract: A power conversion apparatus includes a power converter to directly convert AC power having a frequency into AC power having a different frequency. A gate driver drives the power converter. A gate drive signal generator generates a gate drive signal supplied to the gate driver. Two cutoff devices are coupled between the gate driver and the gate drive signal generator, and supply or cut off the gate drive signal to the gate driver based on a command from an external apparatus. At least one of the two cutoff devices generates a feedback signal. An analyzer determines whether the one cutoff device has an abnormality based on the command and the feedback signal. A cutoff controller controls another one of the two cutoff devices to cut off the gate drive signal to the gate driver when the analyzer determines that the one cutoff device has the abnormality.

Abstract: A power conversion apparatus includes a power converter to directly convert AC power having a frequency into AC power having a different frequency. A gate driver drives the power converter. A gate drive signal generator generates a gate drive signal supplied to the gate driver. Two cutoff devices are coupled between the gate driver and the gate drive signal generator, and supply or cut off the gate drive signal to the gate driver based on a command from an external apparatus. At least one of the two cutoff devices generates a feedback signal. An analyzer determines whether the one cutoff device has an abnormality based on the command and the feedback signal. A cutoff controller controls another one of the two cutoff devices to cut off the gate drive signal to the gate driver when the analyzer determines that the one cutoff device has the abnormality.

Abstract: An interface circuit includes a general-purpose CPU configured to transmit a clock to a serial encoder with which bidirectional serial communication of clock synchronization type is to be performed, the CPU being configured to transmit and receive data to and from the serial encoder; and an additional circuit configured to detect a start bit of reception data transmitted from the serial encoder. The general-purpose CPU starts counting the number of bits of the reception data in response to a detection signal from the additional circuit, the detection signal indicating the detection of the start bit. The CPU stops transmitting the clock to the serial encoder upon completion of counting a predetermined number of bits of the reception data.

Abstract: An interface circuit includes a general-purpose CPU configured to transmit a clock to a serial encoder with which bidirectional serial communication of clock synchronization type is to be performed, the CPU being configured to transmit and receive data to and from the serial encoder; and an additional circuit configured to detect a start bit of reception data transmitted from the serial encoder. The general-purpose CPU starts counting the number of bits of the reception data in response to a detection signal from the additional circuit, the detection signal indicating the detection of the start bit. The CPU stops transmitting the clock to the serial encoder upon completion of counting a predetermined number of bits of the reception data.

Abstract: It is the objective of the present invention to provide a sensorless vector control method and a control apparatus, for an alternating-current motor, that can smoothly restart an alternating-current motor in the free running state. According to the present invention, when a current that flows in an alternating-current motor (2) at a restart time 7 the alternating-current motor (2) continuously flows at a designated current level or higher for a designated period of time, it is determined that the rotational direction or the velocity of the alternating-current motor (2) is incorrectly estimated, and a direct current or a direct-current voltage is again applied to again estimate the rotational direction and the velocity.

Abstract: It is the objective of the present invention to provide a sensorless vector control method and a control apparatus, for an alternating-current motor, that can smoothly restart an alternating-current motor in the free running state. According to the present invention, when a current that flows in an alternating-current motor (2) at a restart time 7 the alternating-current motor (2) continuously flows at a designated current level or higher for a designated period of time, it is determined that the rotational direction or the velocity of the alternating-current motor (2) is incorrectly estimated, and a direct current or a direct-current voltage is again applied to again estimate the rotational direction and the velocity.