Abstract: A power management device includes at least one switching regulator to generate a conversion voltage from an input voltage, a plurality of low drop-out regulators to generate a plurality of output voltages from the conversion voltage, and a controller to estimate drop-out voltages of the low drop-out regulators based on output currents of the low drop-out regulators and to dynamically control the conversion voltage based on the estimated drop-out voltages.

Abstract: A DC-DC converter including an input, an output, a conversion circuit, and a switch control circuit. The input inputs input voltage. The output outputs output voltage. The conversion circuit a plurality of semiconductor switches, and converts the input voltage to the output voltage by switching operation of one or more semiconductor switches of the plurality of semiconductor switches. The switch control circuit selects one or more semiconductor switches performing the switching operation from the plurality of semiconductor switches based on the input voltage and a predetermined lookup table, and controls the switching operation of the one or more semiconductor switches.

Abstract: Switching power supply apparatus having standby mode in which a burst operation is performed. High- and low-side switching elements are series connected across a DC input voltage. A resonant circuit is connected across one of the switching elements. A controller that on-off controls the high-side switching element includes a peak power limiting circuit that monitors input power and outputs a forced turn-off signal upon detecting input power exceeding a determined value. A triangular wave voltage is generated during portions of the burst operation in which a switching frequency of the switching elements is gradually decreased or increased. An oscillation circuit receives the forced turn-off signal from the power limiting circuit, and the triangular wave voltage to generate an on-trigger and off-trigger signals at a switching frequency corresponding to a triangular wave voltage value, and output the off-trigger signal upon receipt of the forced turn-off signal.

Abstract: An electric source control apparatus has: a determining device for determining whether a converter operates in a first mode or a second mode, wherein the first mode prioritizes increase of efficiency of the electric power conversion than the second mode does and the second mode prioritizes suppression of increase of element temperature of the switching element than the first mode does; and a controlling device for controlling the converter so that (i) a switching pattern becomes a first pattern, if the converter operates in the first mode and (ii) the switching pattern becomes a second pattern, if the converter operates in the second mode, wherein the first pattern is capable of increasing the efficiency of the electric power conversion more than the second pattern is and the second pattern is capable of suppressing the increase of the element temperature more than the first pattern is.

Abstract: A power conversion apparatus includes a power conversion circuit, a choke coil, an auxiliary coil, and a rectifier element. The choke coil is disposed between the power conversion circuit and an input side direct current power source. The auxiliary coil is magnetically coupled to the choke coil and is connected in parallel with an output side circuit. The auxiliary coil is wound in a direction so that an excitation current flows from a negative electrode to a positive electrode of the output side circuit when an excitation current flows from a positive electrode to a negative electrode of the direct current power source through the choke coil. The rectifier element is series connection with the auxiliary coil, and cuts off power supply from the direct current power source to the output side circuit through the auxiliary coil and power supply from the output side circuit to the input side.

Abstract: A method is shown to improve any forward topology operation to achieve efficient resonant transitions by actively shorting the magnetizing inductance and release the short at another time thus producing lower switching losses independent of frequency. In another embodiment of this invention the current from the output inductor is allowed to go negative before the freewheeling synchronous rectifier is turned off, pushing the current back into the primary to create a soft transition across the switching elements before they are turned on. In another embodiment of the invention a current source is used to inject a negative current through the freewheeling synchronous rectifier before is turned off with the purpose of transferring the current into the primary to discharge the parasitic capacitances of the primary switchers before are turned on. An optimized control method can be utilized to tailor the frequency to create the necessary conditions requested by the embodiments of the invention.

Abstract: A synchronous rectifier control circuit and the control method thereof for controlling a switching power supply which includes a transformer, a first switch transistor and a second switch transistor. According to one embodiment to the present invention, the control circuit comprises a conducting detection module, a voltage averaging module, a voltage-second balance module and a logic-controlled module. The conducting detection module is comprised of a first reference potential and a conduction signal. The voltage averaging module includes an averaged circuit and outputs a second reference potential. The voltage-second balance module includes a first reference current, a second reference current, a voltage-second balance switch, a voltage-second balance comparator and a timing capacitor, and outputs a reset signal. The logic-controlled module includes a logic circuit to control the second switch transistor to turn on or off.

Abstract: A method for operating an active rectifier including a multitude of controllable semiconductor switching elements, in which a switch is carried out between a first control mode and a second control mode for controlling the semiconductor switching elements, and vice versa, the semiconductor switching elements being controlled with a first switching time in the first control mode and with a second switching time in the second control mode, the second switching time being greater than the first switching time.

Abstract: A controller switches between modes each having a different connection state of a DC power supply and the capacitor with respect to first and second output points by controlling switches. A generation unit generates a reference wave including at least one carrier wave. The modes are classified into a sustaining mode in which no current is caused to flow to the capacitor, a charging mode in which a current is caused to flow to the capacitor, and a discharging mode in which a current in a direction opposite to that in the charging mode is caused to flow to the capacitor. The controller switches between the sustaining mode and a charging or discharging mode according to the comparison result between a signal wave and the reference wave.

Abstract: In one embodiment, a current-fed modular multilevel dual active-bridge DC-DC converter suitable for medium voltage direct current (MVDC) grid or high voltage direct current (HVDC) grid integration is described. The DAB modular converter and the current-fed DAB converter are soft-switched modular multilevel dual-active-bridge (DAB) converters having DC fault ride-through capability. In an additional embodiment a voltage-fed isolated modular dual active-bridge DC-DC converter for medium voltage direct current (MVDC) or high voltage direct current (HVDC) grids or systems is described. In specific embodiments, the converters may be coupled to a battery energy storage system (BESS), wherein the BESS comprises split-battery units and the interface of the isolated DC-DC converter connects the split-battery units to the MVDC or HVDC system.

Abstract: A conducted EMI noise reduction effect close to that achieved by using an optimal modulating waveform as a modulating wave is achieved when employing a frequency spreading technique as a measure against noise when a conducted EMI standard is extended to a low-frequency range. A triangular wave/Hershey's Kiss approximation signal generating unit and a triangular wave generation control unit generate a fundamental triangular wave by a transistor charging a capacitor with a current and a transistor discharging the current from the capacitor. A slope switching signal generating unit generates signals expressing the start and end of a charge period and the start and end of a discharge period. An additional charge or additional discharge is carried out in response to the signals turning a transistor on, and the slope of the triangular wave temporarily increases in that period only.

Abstract: Control methods and related power controllers diminish audible noise in a power supply capable of performing valley switching. The power supply has an inductive device and a power switch. When the power switch is OFF, a winding voltage of the inductive device oscillates to provide an oscillation signal with at least one signal valley. An occurrence number of the signal valley is detected, and is compared with a lock number. When the occurrence number and the lock number fit a predetermined condition, the power switch is turned ON to start a cycle time at a start moment. Whether the start moment falls within an expectation window is checked. The lock number is changed if the start moment falls outside of the expectation window.

Abstract: The present disclosure relates to a reactive power compensation system includes a first measurement unit, a second measurement unit, a reactive power compensation unit, and a controller. The first measurement unit measures impedance of each of at least one load. The second measurement unit measures a voltage and current provided to the at least one load. The reactive power compensation unit compensates the leading reactive power or the lagging reactive power. The controller monitors a change of the impedance in real time, checks a change of the voltage or current according to the change of the impedance, and controls the reactive power compensation unit according to a result of the check to compensate the leading reactive power or the lagging reactive power.

Abstract: A switching power supply apparatus of a current-resonance type, including a first switching element and a second switching element connected in series, a series circuit of a resonant reactor and a resonant capacitor connected in parallel to the first switching element or the second switching element, a control circuit configured to alternately turn on and off the first switching element and the second switching element, and a load detection circuit. The load detection circuit includes a shunt circuit which shunts a resonant current flowing through the resonant reactor and resonant capacitor connected in series to obtain a shunted current, converts the shunted current to a first voltage signal, and outputs the first voltage signal, a switching circuit which switches between the first voltage signal and a second voltage signal of a ground level to generate a third voltage signal, and an averaging circuit which averages the third voltage signal.

Abstract: Voltage applied to switching elements of a power conversion device is suppressed to be within a predetermined range. A power conversion device (1) includes a leg (31) in which switching elements (41, 42) are connected in series, a leg (32) in which switching elements (43, 44) are connected in series, a reactor (61) connected between the midpoint of the switching elements (41, 42) and the switching-element (43) end not connected to the switching element (44), a reactor (62) connected between the midpoint of the switching elements (43, 44) and the switching-element (42) end not connected to the switching element (41), and a DC power source (10) connected between the switching-element (41) end not connected to the reactor (61) and the terminal of the switching element (44) not connected to the reactor (62). Loads can be connected in parallel to the legs (31, 32).

Abstract: A resonant rectifying device includes a transformer having a primary winding and a secondary winding, a primary-side circuit coupled to the primary winding of the transformer, and a secondary-side circuit coupled to the secondary winding of the transformer. The primary-side circuit includes a first field effect transistor (FET) and a second FET coupled in series between a voltage source and a ground, a capacitor, and an inductor. A first side of the capacitor is coupled to a point between the first and the second FETs. A second side of the capacitor is coupled to a first end of the inductor and one end of the primary winding. A second end of the inductor is coupled to the ground. The secondary-side circuit includes a third FET and a fourth FET coupled to a first end and a second end of the secondary winding, respectively.

Abstract: A current mirror circuit includes an input current leg and an output current leg. The input current leg includes: a first bipolar junction transistor (BJT) having a collector terminal configured to receive an input current sourced at a current node and a first metal oxide semiconductor field effect transistor (MOSFET) having a gate terminal coupled to the current node and a source terminal coupled to a base terminal of the first BJT. The output current leg includes: a second BJT having a collector terminal configured to supply an output current and a second MOSFET having a gate terminal coupled to the current node and a source terminal coupled to a base terminal of the second BJT.

Abstract: A power converting apparatus includes a rectifier that converts alternating-current power from an alternating-current power supply into direct-current power, a short-circuit unit that short-circuits the alternating-current power supply via a reactor, and a control unit that controls a short-circuit operation of the short-circuit unit. The control unit changes the number of times of the short-circuit operation during a half cycle of the alternating-current power supply on the basis of a load condition and sets a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply after the change of the number of times of the short-circuit operation to be different from a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply before the change of the number of times of the short-circuit operation.

Abstract: In a reference voltage generation circuit, a reference voltage generation unit 1 is configured to receive, as feedback, a voltage of an output terminal 3; a startup circuit unit 2 has a depletion MOS transistor TR1, and enhancement MOS transistors TR2, TR3; the MOS transistor TR1 has one end connected to a power source 4 and is formed as a constant current connection; the MOS transistor TR2 has one end connected to the power source 4 via a resistor RST, has an opposite end connected to the output terminal 3, and further has a gate connected to an opposite end of the MOS transistor TR1; and the MOS transistor TR3 has one end connected to the opposite end of the MOS transistor TR1, has an opposite end grounded, and further has a gate connected to the output terminal 3. The reference voltage generation circuit can reduce the occurrence of a wasteful current consumption after circuit startup.

Abstract: Circuit and apparatus for improving operating features characteristics of DC power supplies implementing three Phase transformer devices of the type such as 12-step and 24-step transformers. The circuit and apparatus reduces harmonic AC input current while providing almost unity power factor for DC power supply outputs intended for aircraft or marine applications where size and weight are concerns. The circuit includes a passive series connected nonlinear resonant LC circuit connected at each phase of the input to the three phase transformer With the three phase transformer having the added series nonlinear resonant LC circuit, the power supply is enhanced with current limiting for the entire transformer, rectifier and load, due to load shorting, input voltage transients, transformer winding short circuit or rectifier failure. Further, such apparatus provides limiting of power inrush currents during voltage application or turn on, while also providing EMI filtering.