Patent application number | Description | Published |
20120134188 | Systems and Apparatus for Reducing Electromagnetic Interference and Methods of Assembling the Same - An electric machine drive system is described. The system includes an inverter, an electric machine coupled to the inverter by at least one output conductor and including a ground connection, and an active common mode current reducing device coupled between the ground connection of the electric machine and the inverter. | 05-31-2012 |
20120249145 | GRADIENT AMPLIFIER SYSTEM - A gradient amplifier system is presented. An embodiment of a gradient amplifier system that includes a power stage having a plurality of bridge amplifiers, where each of the plurality of bridge amplifiers operates at a first switching frequency. The gradient amplifier system further includes a gradient coil coupled to an output terminal of the power stage and configured to produce a magnetic field proportional to a coil current signal supplied by the power stage. In addition, the gradient amplifier system includes a controller stage coupled to an input terminal of the power stage and configured to generate a pulse width modulated gate signal based on the coil current signal and a reference current signal, where the pulse width modulated gate signal is generated at a second switching frequency upon occurrence of a slew rate associated with the reference current signal is below a determined threshold rate and an amplitude level associated with the reference current signal is above a determined level. Further, the controller stage is configured to apply the generated pulse width modulated gate signal to the power stage for changing an operating frequency of each of the plurality of bridge amplifiers from the first switching frequency to the second switching frequency. | 10-04-2012 |
20130162250 | SYSTEM AND METHOD TO REDUCE POWER LOSS IN A GRADIENT AMPLIFIER - A gradient amplifier system, includes: a power stage comprising a plurality of bridge amplifiers, each operates at a first switching frequency; a gradient coil coupled to the power stage and configured to produce a magnetic field proportional to a coil current signal supplied by the power stage; a controller stage coupled to an input terminal of the power stage and configured to: generate a pulse width modulated gate signal based on the coil current signal and a reference current signal, wherein the pulse width modulated gate signal is generated at a second switching frequency when a slew rate associated with the reference current signal is below a threshold rate for at least a first time period; and apply the pulse width modulated gate signal to the power stage for changing an operating frequency of each of the plurality of bridge amplifiers from the first to the second switching frequency. | 06-27-2013 |
20130162370 | SYSTEMS AND METHODS FOR PROVIDING AN ELECTRIC CHOKE - Systems and methods for an electric choke are provided. The choke may be provided as part of a power transmission arrangement that includes a cable for electrically coupling a power source and a powered device having a ground node and a wire separate from the cable providing a path for a common-mode current through the ground node. The power transmission arrangement also includes an unbalanced choke coupled between the power source and the powered device, wherein a number of turns of the cable in the choke is different than a number of turns of the wire in the choke. | 06-27-2013 |
20140077812 | SYSTEM AND METHOD FOR MAINTAINING SOFT SWITCHING CONDITION IN A GRADIENT COIL DRIVER CIRCUIT - In one embodiment, a system includes a gradient coil driver configured to supply electrical signals to a gradient coil of a magnetic resonance imaging system. The gradient coil driver includes an electronic circuit. The electronic circuit includes a first H-bridge circuit electrically coupled to a power source. The first H-bridge includes a plurality of metal-oxide-semiconductor field-effect transistor (MOSFET) switches; and a plurality of diodes electrically coupled in parallel with each MOSFET switch. Each diode of the plurality of diodes is configured to conduct current to cause zero voltage potential across a source and a drain of one of the plurality of MOSFET switches. The first H-bridge also includes a load configured to regulate currents flowing through each of the plurality of diodes and each MOSFET switch of the plurality of MOSFET switches. | 03-20-2014 |
20140092660 | MULTILEVEL CONVERTER SYSTEM - A power converter includes at least one leg with a first string including a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, wherein the first string is operatively coupled across a first bus and a second bus. The at least one leg also includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, wherein the second string includes a plurality of switching units. The first string includes a first branch and a second branch, wherein the second branch is operatively coupled to the first branch via a third connecting node and the third connecting node is coupled to a ground connection. | 04-03-2014 |
20140233277 | DIRECT CURRENT POWER DELIVERY SYSTEM AND METHOD - A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component. | 08-21-2014 |
20150015066 | METHOD AND SYSTEM FOR CONTROL AND PROTECTION OF DIRECT CURRENT SUBSEA POWER SYSTEMS - A method and a high-voltage DC (HVDC) power system are provided. The system includes a plurality of sending-end (SE) modules coupled in electrical series and divided into at least two groups that each operate independently with respect to an electrical ground and a plurality of receiving-end (RE) power converter modules electrically coupled to the plurality of SE modules, the plurality of RE power converter modules including a fast ground-fault detection and control device, the plurality of RE power converter modules including a receiving-end front-end DC-DC converter controller, and an output current damping control. | 01-15-2015 |
20150022975 | METHOD AND SYSTEM FOR AN IMMERSION BOILING HEAT SINK - A method and system for cooling a heat-generating component are provided. The system includes a heat generating electronic component including a heat conductive face, a heat sink device including at least one open face pin fin array surface directly coupled to the conductive face, each fin including a distal end including an outwardly facing contact area, the contact areas covering only a portion of the conductive face, the contact areas configured to carry electrical current therethrough, and an immersion of dielectric fluid contained in a vessel, the vessel including a heat-conductive hull at least partially submerged in a heat sink fluid. | 01-22-2015 |
20150062991 | METHOD AND SYSTEM FOR POWER CONVERSION - A power converter includes at least one leg including a first string that includes controllable semiconductor switches, a first connecting node, and a second connecting node and that is operatively coupled across a first bus and a second bus. A second string is operatively coupled to the first string via the first connecting node and the second connecting node. The second string includes a plurality of switching modules wherein each of the plurality of switching modules includes a plurality of fully controllable semiconductor switches and at least one energy storage device. The power converter includes a system controller to control activation of the controllable semiconductor switches and switching modules such that a controlled electrical variable is maintained at a first predetermined reference voltage value and the average internal stored energy of the energy storage devices is maintained at a second predetermined reference value. | 03-05-2015 |
20150070802 | METHOD AND SYSTEM FOR ARCHITECTURE, CONTROL, AND PROTECTION SYSTEMS OF MODULAR STACKED DIRECT CURRENT SUBSEA POWER SYSTEM - A high-voltage DC (HVDC) power system and a method of controlling and protecting the HVDC power system includes a plurality of sending-end (SE) modules coupled in electrical series and a plurality of receiving-end (RE) power converter modules electrically coupled to said plurality of SE modules, the RE modules coupled in a switchyard configuration, the switchyard configuration including a plurality of load branches coupled together in electrical series, each load branch including a branch bypass switch configured to bypass load current around an associated load branch, and a branch protection system. | 03-12-2015 |