Patent application number | Description | Published |
20090085405 | POWER CONVERSION DEVICE - A power conversion device including sub-inverters, each connected in series with respective phase of a three-phase main inverter including a smoothing capacitor, which is fed from a power supply via a converter, as a DC input thereof, and feeds power to a load using the sum of outputs of the inverters. A manipulative quantity is determined so that the DC voltage at each of smoothing capacitors which is an input of each of the sub-inverters will follow a command value. The manipulative quantity is added to an output voltage command for the three-phase main inverter, and is subtracted from an output voltage command for the sub-inverters. Thus, power is shifted from the three-phase main inverter to the smoothing capacitors of the sub-inverters. | 04-02-2009 |
20090116268 | POWER CONVERTING APPARATUS - A converter controllable in regenerative running mode, which is a power converting apparatus capable of suppressing harmonics without increasing the size of a reactor, and reducing power loss and electromagnetic noise. A power converter is configured by directly connecting AC sides of single-phase sub-converters having a DC voltage lower than a DC voltage of a 3-phase main converter to AC input lines of individual phases thereof in series. The main converter is driven by one gate pulse per half recurring cycle and a voltage produced by each sub-converter at AC terminals thereof is controlled to match a difference between an AC power supply voltage and a voltage produced by the main converter at AC terminals thereof, whereby phase voltages of the power converter are generated as the sums of phase voltages of the individual converters. | 05-07-2009 |
20100237835 | REACTIVE POWER COMPENSATOR - A capacitor bank unit includes three capacitor banks that have respective capacitances that are multiples of a basic capacitance in accordance with a number sequence of the n-th power of 2. One of the capacitor banks has the basic capacitance, remaining two of the capacitor banks includes two subbanks each. The capacitance of a subbank is set to a capacitance that is a multiple of the basic capacitance in accordance with a number sequence of the m-th power of 2. When any one of the capacitor banks fails, each of capacitor banks following the failed capacitor bank substitutes for a capacitor bank located immediately before itself. | 09-23-2010 |
20120247749 | WATER-COOLED ELECTRICAL APPARATUS - An objective is to prevent excessive temperature decrease of cooling water and to reduce energy loss by a heater. | 10-04-2012 |