Abstract: An interleaved totem-pole power converter (500) includes a direct current, DC, capacitor (502), a pair of low frequency switching devices (504a and 504b) connected in series with each other and in parallel with the DC capacitor and two pairs of high frequency switching devices (506 a, 506b, 506c and 506d) connected in series with each other and in parallel with the DC capacitor (502). The two pairs of high frequency switching devices (506 a, 506b, 506c and 506d) are connected in an interleaving manner to a first output inductor (508a) and a second output inductor (508b) which are connected to an alternating current, AC, capacitor (512), and a resistive load is connected in parallel with the AC capacitor. An auxiliary inductor (510) is connected in between switching legs of the converter (500) with a control system (516,704) configured for regulating a current circulation through the auxiliary inductor (510).

Abstract: According to a non-isolated DCDC resonant conversion control circuit provided in embodiments of this application, an inductor and a capacitor that are resonant are connected in series, so that a current flowing through the inductor is a sine waveform. A waveform coefficient of the sine wave is small, and a conduction loss of the sine wave is low. Therefore, the circuit provided in embodiments of this application can significantly reduce a circuit loss. According to the non-isolated DCDC resonant conversion control method provided in embodiments of this application, not only a phase shift angle can be adjusted to enable a switching transistor to implement zero voltage switching (ZVS) on, but switching frequency can also be adjusted. Therefore, ranges in which a voltage and power of an output interface can be adjusted are large, so that non-isolated wide-range DCDC resonant conversion is implemented.

Abstract: The technology of this application relates to a drive circuit with an energy recovery function, including a control circuit, an energy recovery drive circuit, a switch circuit, and a direct current power supply. The control circuit is configured to control an energy storage capacitor in the energy recovery drive circuit to charge a junction capacitor of the switch circuit at a first moment, and enable the direct current power supply to charge the junction capacitor of the switch circuit through the energy recovery drive circuit at a second moment, so that the switch circuit is switched on. The control circuit is further configured to control the junction capacitor of the switch circuit to charge the energy storage capacitor in the energy recovery drive circuit at a third moment, and enable the junction capacitor of the switch circuit to discharge to a ground through the energy recovery drive circuit at a fourth moment, so that the switch circuit is switched off.

Abstract: A bi-directional AC/DC power conversion apparatus includes a low frequency switching network, a high frequency switching network, and one or more inductors coupled between the high frequency switching network and an AC voltage. A controller provides bi-directional power transfer between a DC voltage and an AC voltage. The controller receives the DC voltage, the AC voltage, and a total current flowing through the inductors, and produces a duty cycle, a switching frequency, and switch control signals configured to operate the switching networks. The required ZVS current is achieved by varying the switching frequency based on the total current, the duty cycle, and the AC and DC voltages. ZVS operation is ensured by adjusting the switching frequency to create an available charge stored in an inductor at the switching instant equal to the charge stored in an output capacitance of a switching device.

Abstract: A power conversion apparatus employs multi-level techniques and wide band-gap semiconductor switching devices to achieve high efficiency in a converter system having high power density. The apparatus may be configured as a bi-directional conversion system capable of operating as both an inverter, configured to receive DC power and produce AC power, and as a rectifier configured to receive AC power and produce DC power. The apparatus is especially suitable for electric vehicle (EV) applications.

Abstract: An AC-DC power converter has a power factor correction stage that receives grid power and produces DC bus power. A DC-DC converter stage receives the DC bus power and produces a DC output power. Energy storage is provided by a larger capacitance value first capacitor and a smaller capacitance value second capacitor coupled in series across the DC bus power with a switching device coupled in parallel with the smaller second capacitor. During converter start-up, the switching device is turned off and inrush current is controlled by transferring energy from the second capacitor to the first capacitor. During operation the switching device is turned on and the first capacitor provides energy storage for the DC bus power. When grid power is disconnected, hold-up time is extended by turning the switching device off and transferring energy from the first capacitor to the second capacitor.

Abstract: An isolated bidirectional active-half-bridge resonant DC-DC power conversion apparatus employs dual control strategies to regulate bi-directional power flow between two DC sources. The apparatus includes a first half bridge switching network configured to convert a first DC power to an AC power. A series resonant impedance transfers the AC power to a first winding of a transformer. A first inductor and a second inductor are connected in series across a second winding of the transformer and form a positive DC node. A second half bridge switching network is connected in parallel with a first clamping capacitor, with a central node connected to the first end of the second winding. A third half bridge switching network is connected in parallel with a second clamping capacitor, with a central node connected with the second end of the second winding. The clamping capacitors are connected with a negative DC node.

Abstract: A direct power AC/DC conversion apparatus employs a dual branch topology. A first branch includes a first AHB switching network configured to receive an AC grid power and produce an AC power, coupled through a series resonant impedance to a first primary winding of a transformer. The first switching network includes two bi-directional switches coupled in series where each bi-directional switch includes two switching devices coupled in series in opposite polarity. A secondary winding of the transformer is coupled through an SR switching device to an output DC power. A second branch includes a diode bridge, configured to receive the AC grid power and produce a DC power, coupled to a second AHB switching network. The second AHB switching network is coupled through a second series resonant impedance to a second primary winding of the transformer. Each of the first and second branches are operated alternately and independently.

Abstract: A resonant AC/DC converter. An input end of a half bridge rectifier circuit is connected to an alternating current power supply. A clamping surge protection circuit is connected to the half bridge rectifier circuit in parallel, and is connected to a resonant capacitor in a resonant DC/DC conversion circuit in parallel. When a voltage of the alternating current power supply is greater than a voltage of a bus capacitor, the clamping surge protection circuit is configured to prevent a surge signal entering the resonant DC/DC conversion circuit. When the voltage of the alternating current power supply is less than or equal to a voltage of a direct current bus, a voltage of the resonant capacitor is clamped. The resonant DC/DC conversion circuit performs electric energy conversion on the pulsating direct current that is output by the half bridge rectifier circuit, and then performs output.

Abstract: A control method for a hybrid three-port DC-DC power converter combining a dual active bridge converter and a dual active bridge series resonant converter topology. The controller includes a first control loop to regulate power flow between the first port and the second port and a second control loop to regulate power flow between the second port and the third port. The first control loop employs a three-mode control methodology to regulate power flow through the dual active bridge converter between the first port and the second port. The second control loop is configured with a lower bandwidth than the first control loop and regulates power flow through the dual active bridge series resonant converter between the second port and the third port.

Abstract: A power converter apparatus employs an energy recovery auxiliary circuit to suppress overvoltage oscillations and achieve high efficiency in a resonant LLC power converter system having high power density. The power converter apparatus includes an inverter configured to receive a DC input power and produce an AC voltage, a resonant tank including a resonant inductor and a resonant capacitor coupled between the AC voltage and a primary winding of a transformer, a rectifier configured to produce a DC output power coupled to a secondary winding of the transformer. The power converter suppresses overvoltage oscillations on rectifier switches by employing an energy recovery auxiliary circuit to transfer, during a transition period, current from the secondary side to a clamping capacitor conductively coupled to the primary side of the converter. The energy is then recovered during a subsequent power transfer cycle, thereby improving overall efficiency of the power converter.

Abstract: The technology of this application relates to a drive circuit with an energy recovery function, including a control circuit, an energy recovery drive circuit, a switch circuit, and a direct current power supply. The control circuit is configured to control an energy storage capacitor in the energy recovery drive circuit to charge a junction capacitor of the switch circuit at a first moment, and enable the direct current power supply to charge the junction capacitor of the switch circuit through the energy recovery drive circuit at a second moment, so that the switch circuit is switched on. The control circuit is further configured to control the junction capacitor of the switch circuit to charge the energy storage capacitor in the energy recovery drive circuit at a third moment, and enable the junction capacitor of the switch circuit to discharge to a ground through the energy recovery drive circuit at a fourth moment, so that the switch circuit is switched off.

Abstract: According to a non-isolated DCDC resonant conversion control circuit provided in embodiments of this application, an inductor and a capacitor that are resonant are connected in series, so that a current flowing through the inductor is a sine waveform. A waveform coefficient of the sine wave is small, and a conduction loss of the sine wave is low. Therefore, the circuit provided in embodiments of this application can significantly reduce a circuit loss. According to the non-isolated DCDC resonant conversion control method provided in embodiments of this application, not only a phase shift angle can be adjusted to enable a switching transistor to implement zero voltage switching (ZVS) on, but switching frequency can also be adjusted. Therefore, ranges in which a voltage and power of an output interface can be adjusted are large, so that non-isolated wide-range DCDC resonant conversion is implemented.

Abstract: The present disclosure relates to a DC-to-DC converter. The DC-to-DC converter includes a first port coupled to a first full bridge and a transformer coupled to the first full bridge and to a second full bridge. The DC-to-DC converter further includes a second port coupled to the second full bridge; a first inductor coupled between the second full bridge and the second port; and a first freewheeling circuit including a first diode being coupled in series with a switch. The first freewheeling circuit is further coupled in parallel with the first inductor between the second full bridge and the second port. Thereby, the DC-to-DC converter has a wide input and wide output (WIWO) range and a voltage gain that is linear.

Abstract: Example bidirectional energy transmission apparatus and methods are described. An example of a bidirectional energy transmission apparatus includes a controller and a bidirectional energy transmission circuit. A control terminal of the controller is connected to a controlled terminal of the bidirectional energy transmission circuit. In the example, the controller is configured to control the bidirectional energy transmission circuit to be in a rectification working state, so as to convert, into a first direct current voltage, a three-phase or single-phase alternating current voltage that is input from a first port of the bidirectional energy transmission circuit, and output the first direct current voltage from a second port of the bidirectional energy transmission circuit. The controller is configured to control the bidirectional energy transmission circuit to be in an inversion working state, so as to convert, into a three-phase or single-phase alternating current voltage.

Abstract: A power conversion apparatus employs multi-level techniques and wide band-gap semiconductor switching devices to achieve high efficiency in a converter system having high power density. The apparatus may be configured as a bi-directional conversion system capable of operating as both an inverter, configured to receive DC power and produce AC power, and as a rectifier configured to receive AC power and produce DC power. The apparatus is especially suitable for electric vehicle (EV) applications.

Abstract: A resonant converter circuit comprises a multi-level inverter circuit placed before a resonant unit, and the multi-level inverter circuit can reduce a voltage to be input to the resonant unit. The reduced input voltage of the resonant unit results in a drop in an output voltage of the entire resonant converter circuit. In this process, the final output voltage is adjusted by adjusting the input voltage of the resonant unit, with no need to substantially adjust a switching frequency of the resonant converter circuit.

Abstract: A resonant converter circuit comprises a multi-level inverter circuit placed before a resonant unit, and the multi-level inverter circuit can reduce a voltage to be input to the resonant unit. The reduced input voltage of the resonant unit results in a drop in an output voltage of the entire resonant converter circuit. In this process, the final output voltage is adjusted by adjusting the input voltage of the resonant unit, with no need to substantially adjust a switching frequency of the resonant converter circuit.

Abstract: A switching circuit includes a first half-bridge circuit, a second half-bridge circuit and a voltage divider circuit connected in parallel with each other and a DC input power (VDC). The first half-bridge circuit includes a first pair of series connected switches and the second half-bridge circuit includes a second pair of series connected switches.

Abstract: A resonant circuit includes first, second, and third input nodes configured to receive a three phase input power and is formed as a delta circuit including a first leg connected between a first corner node and a second corner node, a second leg connected between the second corner node and a third corner node, and a third leg connected between the third corner node and the first corner node. A first outer resonant device is connected between the first input node and the first corner node, a second outer resonant device connected between the second input node and the second corner node, and a third outer resonant device connected between the third input node and the third corner node. Each leg of the delta circuit includes an inner resonant device connected in series with a corresponding transformer.