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 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 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: 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: 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: 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: 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.

Abstract: A power adapter includes a power converting circuit, a connecting terminal and a controller. The power converting circuit is used to convert an input voltage to an output voltage according to a control signal. The connecting terminal is connected to an electronic device to allow the output voltage outputted by the power converting circuit to charge the electronic device. The controller receives an identifying command from the electronic device when the electronic device is connected to the connecting terminal, and outputs the control signal according to the identifying command.

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: 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: Systems, methods and apparatus for efficient control and biasing of pass devices driven into their triode region of operation are described. The pass devices are arranged in a cascode configuration comprising a plurality of stacked devices. Biasing of the cascode devices can be according to a voltage division scheme which provides a substantially equal voltage division across the stacked devices when the voltage across the stack is high, and provides a skewed voltage division across the stacked devices when voltage across the stack is reduced, while protecting each of the devices from overvoltage and biasing the cascoded devices for a low RON. An exemplary implementation of an LDO controlling the pass devices for providing burst RF power to a power amplifier is described.

Abstract: An overshoot reduction circuit within a low dropout voltage regulator eliminates an overshoot at an output terminal resulting from a transient fault condition occurring at an input or output terminal. The overshoot reduction circuit monitors to sense if there is a transient fault condition occurring at the input or output terminal and provides a Miller capacitance at the output terminal of a differential amplifier of the low dropout voltage regulator to prevent the output of the differential amplifier from being discharged to ground during the transient. A control loop circuit balances current within an active load of the differential amplifier to clamp the output of the differential amplifier to its normal operating point. When the transient fault condition ends, the output voltage of the differential amplifier is set such that a pass transistor of the low dropout regulator responds quickly to resume the regulation to reduce or eliminate the overshoot.

Abstract: A multi-phase power controller is adapted for operating N power channels and is coupled to M drivers and an external system. The M drivers respectively have an enabling pin, and the multi-phase power controller includes a power state pin and M control pins. The power state pin is coupled to the enabling pin of each of the M drivers and the external system. The M control pins are coupled to the M drivers. In a power start period of the multi-phase power controller, the number of the power channels operated by the multi-phase power controller is less than N. After the power start period, the multi-phase power controller enables the M drivers through the power state pin and notifies the external system that a power start procedure has been completed through the power state pin.

Abstract: A three-level photovoltaic inverter pulse width modulation method and a three-level photovoltaic inverter pulse width modulator. The method includes: when it is detected that potential safety hazards exist in a three-level photovoltaic inverter, switching the pulse width modulation mode of the three-level photovoltaic inverter into a 13-vector space vector pulse width modulation mode, to solve the fault or abnormal problems in the three-level photovoltaic inverter such as midpoint potential offset or excessively large common mode leakage current formed when the ground stray capacitance of a photovoltaic assembly is large, wherein according to the 13-vector SVPWM mode, 12 short vectors in 27 on-off state vectors of the three-level photovoltaic inverter are abandoned, and only six long vectors, six middle vectors and three zero vectors are reserved.

Abstract: A circuit including: a three-level buck converter having: a plurality of input switches and an inductor configured to receive a voltage from the plurality of input switches, the plurality of input switches coupled with a first capacitor and configured to charge and discharge the first capacitor; a second capacitor at an output of the buck converter; and a switched capacitor at an input node of the inductor, wherein the switched capacitor is smaller than either the first capacitor or the second capacitor.

Abstract: The disclosure relates to a control circuit and a control method for a power converter. The power converter comprises a power switch and an inductor being coupled to the power switch. The control circuit controls operation of the power switch to charge and discharge the inductor for generating an inductor current and providing an output current. The control circuit controls the power switch to be turned on when or after an inductor current detection signal is zero, and controls the power switch to be turned off when the inductor current detection signal reaches a peak reference signal or when the power switch has been turned on for a maximum on time. The control circuit also adjusts the maximum on time in accordance with the inductor current detection signal, so that the power converter provides a constant output current to a load. The control circuit operates at a peak-value current mode and maintains the current of the power converter nearly stable without obtaining a compensation signal.