Abstract: Provided is a matrix converter including a power converter, a commutation controller, and a compensator. The power converter includes a plurality of bidirectional switches. The commutation controller performs one of a three-step commutation operation and a four-step commutation operation by the bidirectional switches as a switch source and the bidirectional switches as a switch destination when an input terminal to be connected to an output terminal is switched by on/off control of the bidirectional switches. The compensator compensates for an output voltage error generated when the input terminal to be connected to the output terminal is switched, based on a potential difference before and after the switching of the input terminal to be connected to the output terminal, an output current of the output terminal, and capacitance between input and output terminals of unidirectional switches.

Abstract: A matrix converter according to embodiments includes a power conversion unit and drive controllers. The power conversion unit includes a plurality of bidirectional switches for connecting each phase of an alternating-current (AC) power supply with each phase of a rotary electric machine. When the voltage of the AC power supply is a predetermined value or less, the drive controllers control the power conversion unit to supply reactive power from the power conversion unit to the AC power supply and to control the torque of the rotary electric machine.

Abstract: A matrix converter includes a power converter and a controller. The power converter includes bidirectional switches each having a controllable conducting direction. The bidirectional switches are disposed between input terminals and output terminals. The input terminals are respectively coupled to phases of an AC power source. The output terminals are respectively coupled to phases of a load. The controller controls the bidirectional switches. A first commutation controller performs commutation control when the conducting direction is unidirectional. A second commutation controller performs the commutation control when the conducting direction is bidirectional. A selector selects between the first commutation controller and the second commutation controller to perform the commutation control based on a state of an output current from the power converter.

Abstract: A matrix converter includes a power converter and a controller. The power converter includes bidirectional switches each having a conducting direction controllable by switching elements. The bidirectional switches are disposed between input terminals coupled to phases of an AC power source and output terminals coupled to phases of a load. A first commutation controller performs commutation control based on a first commutation. A second commutation controller performs the commutation control based on a second commutation. A selector selects between the first and second commutation controllers and to perform the commutation control based on a vector of an output current or an output voltage from the power converter or a vector of an input voltage or an input current from the AC power source to the power converter.

Abstract: A matrix converter according to an embodiment includes a voltage command corrector and a drive signal generator. The voltage command corrector corrects the magnitude of an output voltage command on the basis of amplitude variations of an input current from an AC power supply to a power converter, the amplitude variations being caused by a ripple component of the input current. The drive signal generator generates drive signals that turn ON/OFF a plurality of bidirectional switches on the basis of the output voltage command corrected by the voltage command corrector.

Abstract: Provided is a matrix converter including a power converter, a commutation controller, and a compensator. The power converter includes a plurality of bidirectional switches. The commutation controller performs one of a three-step commutation operation and a four-step commutation operation by the bidirectional switches as a switch source and the bidirectional switches as a switch destination when an input terminal to be connected to an output terminal is switched by on/off control of the bidirectional switches. The compensator compensates for an output voltage error generated when the input terminal to be connected to the output terminal is switched, based on a potential difference before and after the switching of the input terminal to be connected to the output terminal, an output current of the output terminal, and capacitance between input and output terminals of unidirectional switches.

Abstract: A motor includes a rotor including a rotor core provided with a plurality of permanent magnets in the circumferential direction and a stator including a stator core on which multi-phase stator coils are wound. The rotor has a structure in which the change pattern of magnetic properties of the rotor core or the permanent magnets changes in the circumferential direction, and the stator has a structure in which first and second stator coils of the stator coils are wound on the stator core for each phase in such a manner that passage of current is optionally switched, and when the passage of current is switched to the second stator coil, the distribution pattern of a magnetic field formed on the inner circumferential side by the stator has uniqueness over the whole circumference.

Abstract: The motor includes: a rotor that includes a rotor core provided with a plurality of permanent magnets in a circumferential direction; and a stator that includes a stator core on which multi-phase stator coils are wound and is arranged facing the rotor with a predetermined air gap therebetween. The rotor has a structure in which the change pattern of magnetic properties of the rotor core or the permanent magnets changes stepwise in the circumferential direction. The stator has a structure in which the distribution pattern of a magnetic field generated by the stator coils with one phase or with a combination of the phases has uniqueness over a whole circumference.

Abstract: A matrix converter according to one aspect of an embodiment includes a plurality of bidirectional switches and a controller. The bidirectional switches connect each phase of an alternating current (AC) power supply with each phase of the rotary electric machine. The controller performs power conversion control between the AC power supply and the rotary electric machine by controlling a plurality of unidirectional switching elements constituting the bidirectional switches individually. The controller performs switching control for advancing the timing at which the unidirectional switching elements constituting the bidirectional switches are switched ON from that in 120-degree conduction control, and for extending a period for which the unidirectional switching elements are kept ON from that in the 120-degree conduction control.

Abstract: A matrix converter according to an embodiment includes a plurality of bidirectional switches and a controller. The bidirectional switches connect each of phases of an alternating current (AC) power supply with each of phases of a rotary electric machine. The controller controls the bidirectional switches to perform power conversion control between the AC power supply and the rotary electric machine. The controller performs on/off control individually on a plurality of unidirectional switching elements constituting the bidirectional switches by using both 120-degree conduction control and PWM control.

Abstract: A matrix converter includes: a power conversion unit provided between an AC power supply and a rotational machine; and a controller for performing power conversion control therebetween by controlling the power conversion unit. The power conversion unit includes multiple bidirectional switches each of which has at least one first directional switching element and at least one second directional switching element. Further, the controller includes a first drive control unit performing the power conversion by simultaneously turning on both of the first directional switching element and the second directional switching element, and a second drive control unit performing the power conversion by turning on one of the first directional switching element and the second directional switching element.

Abstract: There is here disclosed an apparatus for continuously measuring on an on-line system a flash point of an intermediate fraction such as kerosene in a petroleum distillation process from a difference between gas concentrations of the intermediate fraction at two predetermined temperatures; and a method for controlling the flash point of the intermediate fraction from the thus measured value.