Patent classifications
H02M7/4826
Power converter having resonant frequencies around two and four times the switching frequency
A power converter includes: input terminals for inputting a DC voltage; output terminals for outputting an AC voltage; a switch; a first resonant capacitance connected between both ends of the switch; a first LC resonance circuit connected in series with the switch between the output terminals; and a second LC resonance circuit connected between the input terminals and the switch. The first LC resonance circuit includes an inductance and a capacitance in series. When the input terminals are shorted, frequency characteristics of an impedance of the second LC resonance circuit include first to fourth resonant frequencies. The first resonant frequency is higher than a switching frequency of the switch. The second and fourth resonant frequencies are around double and four times the switching frequency. The impedance has local maxima at the first and third resonant frequencies and local minima at the second and fourth resonant frequencies.
DISCHARGE GENERATOR
In a discharge generator, a switch is connected to a DC power source, and a transformer includes a primary coil connected to the switch, and a secondary coil magnetically coupled to the primary coil and connected to a discharge load. A power measuring unit measures input power supplied from the direct-current power source. A control unit controls on-off switching operations of the switch to thereby convert an input direct-current voltage to an alternating-current voltage. The control unit changes a switching frequency of the on switching operations of the switch while performing an analysis of a frequency characteristic of the input power based on change of the switching frequency. The control unit determines whether the discharge load is a normal state or at least one of predetermined failure modes has occurred in the discharge load in accordance with a result of the analysis of the frequency characteristic of the input power.
Transaction based network application signatures for text based protocols
A method for profiling network traffic of a network. The method includes extracting cells from bi-directional payloads generated by a network application, wherein each cell comprises at least one direction reversal in a corresponding bi-directional flow, generating a cell group comprising a portion of the cells that are similar, analyzing the cell group to generate a signature of the network application, and classifying, based on the signature of the network application, a new bi-directional flow as being generated by the network application.
TRANSMISSION SYSTEM FOR CONTACTLESSLY TRANSMITTING ENERGY
Method for contactlessly transmitting electrical energy to a load (17) using a transmission system (1), having the steps of: converting alternating current from an alternating current source (4) into direct current using a primary rectifier (5), converting the direct current generated by the primary rectifier (5) into alternating current using a primary inverter (7), changing a primary parameter (di) at a component (38) of a primary part (2) of the transmission system, such that the electrical power consumed by a load (17) is changed as a result, contactlessly transmitting the electrical energy of the alternating current generated by the primary inverter (7) from a primary coil (9) to a secondary coil (12), converting the alternating current generated in the secondary coil (12) into direct current using a secondary rectifier (15), changing a secondary parameter at a component (16) of a secondary part (3) of the transmission system (1), such that the electrical power consumed by the load (17) is changed as a result, supplying electrical energy as direct current to the load (17), wherein an A-efficiency of the contactless transmission of energy with respect to a secondary A-parameter is determined, the secondary parameter is then changed from the secondary A-parameter to at least one secondary B-parameter and a B-efficiency is determined for the at least one secondary B-parameter, and that efficiency with the maximum efficiency is selected from the A-efficiency and from the at least one B-efficiency and this selected maximum efficiency is referred to as C-efficiency, and energy is then contactlessly transmitted with a secondary C-parameter assigned to the C-efficiency as an iteration step for determining the secondary C-parameter.
RESONANCE-TYPE POWER CONVERSION DEVICE AND ABNORMALITY DETERMINING METHOD
A resonance power conversion device includes a bridge circuit, a transformer, a current detection circuit, and a control circuit. The bridge circuit includes a plurality of switching elements and receives a DC power. The transformer is connected to an output side of the bridge circuit. The current detection circuit detects a value of a current flowing through at least one of the plurality of switching elements. The control circuit determines whether or not an abnormality is occurring in the resonance power conversion device, based on the value detected by the current detection circuit at a predetermined time during a switching control.
THREE PHASE INVERTER GRID VOLTAGE FEED FORWARD METHOD UNDER UNBALANCED OPERATING CONDITIONS
A system and method for controlling a grid-connected inverter to provide negative sequence current during unbalanced grid operating conditions. The system uses a combination of feedforward and feedback controls to compute voltage signals which are used to control the inverter switches. The system includes both positive and negative sequence current controllers with voltage feedforward terms. The measured grid voltage is directly fed forward to the positive sequence control through a predictive algorithm, so that the instantaneous voltage information is kept, reducing the influence of grid voltage harmonics on the quality of the output current. The predictive voltages include positive, negative and harmonic component information of the grid voltage signals.
Resonant inverter device
In a resonant inverter device, a main circuit is configured to convert input power supplied from a direct-current (DC) power source into alternating-current (AC) power and supply the AC power to a resonance load as output power, and a controller is configured to control operations of the main circuit. In the controller, a deriver is configured to derive a power loss or circuit efficiency of the main circuit as a conversion loss parameter of the main circuit, and an input power calculator is configured to calculate an increased target output value by increasing the target output value using the conversion loss parameter, as a target value of input power that is input to the main circuit. In the controller, an operation controller is configured to control operations of the main circuit such that the calculated target value of the input power is input to the main circuit.
PLUG-AND-PLAY RIPPLE PACIFIER FOR DC VOLTAGE LINKS IN POWER ELECTRONICS SYSTEMS AND DC POWER GRIDS
In many power electronics systems, there is an intermediate DC-link stage for facilitating the power processing of different sources to their loads. A device called a plug-and-play ripple pacifier (RP) directly plugged into the DC-link, and actively removes undesired DC-link ripple, thereby eliminating the reliance on electrolytes capacitors for stabilizing the system and remove ripple. Importantly, the use of this device is non-invasive to the operation of its host systems, and requires no modification of existing hardware. It is suitable for the protection of DC utilities/systems and can also be used as a direct replacement of ripple-canceling E-Caps in power converters device.
Vehicle Capacitor Assembly
An electrified vehicle capacitor assembly including a film capacitor assembly and a support structure is provided. The film capacitor assembly may include a stack of alternating electrodes and film layers. The electrodes may be offset from one another to alternatively contact opposing terminals. The support structure may include coolant channels and may be arranged to orient the film capacitor assembly adjacent an inverter assembly and such that each is in conductive thermal communication with at least one of the coolant channels. The film capacitor assembly further includes a stack of alternating metal foils and film layers disposed between a pair of contact layers, a pair of terminals, and a first thermal plate. Each of the pair of terminals is disposed on an outer side of one of each of the pair of contact layers.
POWER SUPPLY HAVING FOUR QUADRANT CONVERTER AND TECHNIQUES FOR OPERATION
A power supply, including a primary pre-converter, coupled to supplying mains, configured to receive an AC voltage at low frequency and output a high DC voltage, and further configured to receive the high DC voltage and to output the alternating current; a primary converter, disposed on a primary side of the power supply, coupled to the high DC voltage from the primary pre-converter; an isolating transformer to receive the high frequency AC voltage and output a high frequency secondary AC voltage, and to receive a high frequency secondary AC current and to output primary high frequency AC current; and an output converter, on a secondary side of the power supply, wherein the output converter is configured to receive high frequency AC voltage from the isolating transformer and to output a DC voltage of a first or second polarity to an output, and wherein the output converter is configured to receive DC current of a first or second direction from the output and to output a high frequency AC current to the isolating transformer.