Abstract: A driving system for driving an AC motor, which is capable of promptly switching to an individual inverter operation mode, wherein a control instruction for each of a plurality of power converters is generated by summing outputs of a plurality of current compensation units connected in parallel, and each of the plurality of current compensation units makes compensation to reduce a deviation of a detected output current value of an associated power converter from a current instruction value to be outputted from the power converter to zero.

Abstract: A semiconductor electric power conversion device includes a converter unit and an inverter unit, each having a group of parallel capacitors and multiple switching elements. Subdivided positive conductive connections associated with the converter unit and divided positive conductive connections associated with the inverter unit are formed at a positive side conductor connected to capacitors; while divided negative conductive connections associated with the converter unit and divided negative-polarity conductive connections associated with the inverter unit are formed at a negative polarity side conductor, connected to capacitors. The positive and negative polarity conductors have a multilayer structure with a dielectric plate interposed therebetween.

Abstract: In a semiconductor electric power conversion device including a converter unit and an inverter unit each having a group of parallel-connected capacitors and multiple switching elements, subdivided positive-polarity conductive connection (connecting conductor) sections 21a1-21a3 associated with the converter unit and divided positive-polarity conductive connection (connecting conductor) sections 21b1-21b3 associated with the inverter unit are formed at a positive polarity side conductor 21 being connected to capacitors while divided negative-polarity conductive connection (connecting conductor) sections 22a1-22a3 associated with the converter unit and divided negative-polarity conductive connection (connecting conductor) sections 22b1-22b2 associated with the inverter unit are formed at a negative polarity side conductor 22 as connected to capacitors, wherein the positive polarity side conductor 21 and negative polarity side conductor 22 are formed to have a multilayer structure with a dielectric plate 20 inte

Abstract: A driving system for driving an AC motor, which is capable of promptly switching to an individual inverter operation mode, wherein a control instruction for each of a plurality of power converters is generated by summing outputs of a plurality of current compensation units connected in parallel, and each of the plurality of current compensation units makes compensation to reduce a deviation of a detected output current value of an associated power converter from a current instruction value to be outputted from the power converter to zero.

Abstract: In a current source power converting apparatus, in which an AC to DC converter is coupled to a DC to AC inverter through a DC reactor, two energy absorbing devices are coupled to DC terminals of the converter and the inverter, respectively, whereby there is formed a circulation circuit for circulating a current through the two energy absorbing devices and the DC reactor, when a voltage, which is higher than a predetermined value, is induced by an inductance of the DC reactor.

Abstract: An inverter, which supplies an induction motor for driving an elevator with DC power, is controlled by means of a vector control method. A rotating angular speed of the induction motor is detected from a torque component of a detected motor current. A present position of an elevator cage is calculated on the basis of the detected rotating angular speed.

Abstract: A dv/dt protection circuit device for an AC-DC converter apparatus including control board switching arrangement having a current cut-off function which conducts an interrupts current from a power source to a load and refluxes the load current while the current is uninterrupted by a full-wave bridge rectifier circuit having a plurality of arms. Each arm of the bridge rectifier circuit connects a reactor for suppressing a rate of change of a power source line voltage of the bridge rectifier circuit at the switching time of the switching arrangement and a condenser is provided for absorbing an overvoltage generated at an inductance on the side of the power source, the condenser being connected on the side of the power source connected to the bridge rectifier circuit.