| Patent application number | Description | Published |
|---|
| 20080253158 | Power Converter - There are provided: sets of pairs of main circuit switching elements ( | 10-16-2008 |
| 20090135636 | ELECTRIC POWER CONVERSION SYSTEM - An electric power conversion system including a direct current power supply, plural main circuit switching devices bridge-connected to convert the direct current to alternating current, including free wheeling diodes connected in reverse parallel thereto, respectively, and a reverse voltage application circuit applying a reverse voltage smaller than the direct current power supply to each free wheeling diode, upon cutoff of back-flow current of the free wheeling diode. The reverse voltage application circuit includes in series connection a low-voltage direct current power supply having a voltage lower than the direct current power supply, a reverse voltage application switching device having holes as a majority current and a lower withstand voltage than the main circuit switching devices and adapted to turn on upon reverse recovery of the free wheeling diode, and an auxiliary diode having a shorter reverse recovery time than the free wheeling diode. | 05-28-2009 |
| 20090261774 | VARIABLE-FLUX MOTOR DRIVE SYSTEM - A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy. | 10-22-2009 |
| 20090279335 | POWER CONVERTER - To provide a power converter, comprising: a pair of main circuit switching elements to which diodes are connected; a means for generating a first PWM basic signal for driving a main circuit switching element; and a reverse voltage application circuit to be operated, triggered by a second PWM basic signal which differs from the first PWM basic signal only in phase. | 11-12-2009 |
| 20100201294 | VARIABLE MAGNETIC FLUX DRIVE SYSTEM - A variable magnetic flux motor drive system includes: a variable magnetic flux motor having a variable magnet which is a low-coercive permanent magnet; an inverter that drives the variable magnetic flux motor | 08-12-2010 |
| 20100321966 | SEMICONDUCTOR SWITCH AND POWER CONVERSION SYSTEM PROVIDED WITH SEMICONDUCTOR SWITCH - A semiconductor switch is provided with a main element having reverse conductivity and serving as a voltage-driven switching element having a high withstand voltage, an auxiliary element serving as a voltage-driven switching element having a withstand voltage lower than that of the main element, and a high-speed freewheel diode having a withstand voltage equal to that of the main element, wherein a negative pole of the main element is connected to a negative pole of the auxiliary element to define the positive pole of the main element as a positive pole terminal and the positive pole of the auxiliary element as a negative pole terminal, and the high-speed freewheel diode is parallel-connected between the positive pole terminal and the negative pole terminal so that a direction from the negative pole terminal toward the positive pole terminal constitutes a forward direction. | 12-23-2010 |
| 20110216568 | SYSTEM INTERCONNECTION INVERTER - The present invention includes: an inverter | 09-08-2011 |
| 20110309874 | SEMICONDUCTOR SWITCHING SYSTEM - According to one embodiment, a semiconductor switch includes a first element that includes a switching element and an anti-parallel diode. The switching element has a breakdown voltage and is coupled to a control terminal and second and third terminals. The semiconductor switch further includes a second element having a breakdown voltage lower than that of the first element. The second element is coupled to a control terminal and second and third terminals. The semiconductor switch also includes a flyback diode having a breakdown voltage substantially similar to that of the first element. A negative electrode of the first element is connected to a negative electrode of the second element and the flyback diode is connected in parallel between a positive terminal of the first element and a positive terminal of the second element. The control terminal for the first element and the control terminal for the second element are coupled to one or more control circuits independently of each other. | 12-22-2011 |
