Abstract: The present invention discloses a high step-down modular DC power supply, belonging to the field of power electronics technology, and the high step-down modular DC power supply includes an upper modular cascade circuit string, a lower modular cascade circuit string, a load, and an input source, where the upper modular cascade circuit string includes i upper sub-module circuits, and the lower modular cascade circuit string includes j lower sub-module circuits. A combination manner of module circuits includes: upper module string cascading, lower module string cascading, and hybrid cascading of the upper module string and the lower module string. The power supply is formed to be a high voltage step-down ratio power supply with high voltage direct current input and low voltage direct current output through modular cascading.

Abstract: A voltage conversion circuit includes: an inductor, a first switch module, N second switch modules connected in series, N third switch modules connected in series, and N?1 flying capacitors. One terminal of the first switch module is separately connected to one terminal of the N second switch modules connected in series and one terminal of the N third switch modules connected in series. The other terminal of the N third switch modules connected in series is connected to a positive electrode of a high-voltage power supply. The other terminal of the first switch module and the other terminal of the N second switch modules connected in series are connected to a negative electrode of the high-voltage power supply. A low-voltage power supply is connected to the two terminals of the first switch module through the inductor.

Abstract: A voltage conversion circuit includes: an inductor, a first switch module, N second switch modules connected in series, N third switch modules connected in series, and N?1 flying capacitors. One terminal of the first switch module is separately connected to one terminal of the N second switch modules connected in series and one terminal of the N third switch modules connected in series. The other terminal of the N third switch modules connected in series is connected to a positive electrode of a high-voltage power supply. The other terminal of the first switch module and the other terminal of the N second switch modules connected in series are connected to a negative electrode of the high-voltage power supply. A low-voltage power supply is connected to the two terminals of the first switch module through the inductor.

Abstract: A resonance control method for differentiated phase correction under asymmetric positive and negative bilateral frequency domains includes a differentiated phase correction resonance control link with an independent phase correction angle at each resonance point, a decoupling link and a delay compensation link. As a high power converter has the characteristic of asymmetric positive and negative bilateral frequency domains under resonance control with decoupling, stability margin of a control link is enhanced while a negative-sequence current suppression capability is realized by means of differentiated phase correction at positive and negative resonance poles.

Abstract: The present invention discloses a high step-down modular DC power supply, belonging to the field of power electronics technology, and the high step-down modular DC power supply includes an upper modular cascade circuit string, a lower modular cascade circuit string, a load, and an input source, where the upper modular cascade circuit string includes i upper sub-module circuits, and the lower modular cascade circuit string includes j lower sub-module circuits. A combination manner of module circuits includes: upper module string cascading, lower module string cascading, and hybrid cascading of the upper module string and the lower module string. The power supply is formed to be a high voltage step-down ratio power supply with high voltage direct current input and low voltage direct current output through modular cascading.

Abstract: A voltage conversion circuit includes: an inductor, a first switch module, N second switch modules connected in series, N third switch modules connected in series, and N?1 flying capacitors. One terminal of the first switch module is separately connected to one terminal of the N second switch modules connected in series and one terminal of the N third switch modules connected in series. The other terminal of the N third switch modules connected in series is connected to a positive electrode of a high-voltage power supply. The other terminal of the first switch module and the other terminal of the N second switch modules connected in series are connected to a negative electrode of the high-voltage power supply. A low-voltage power supply is connected to the two terminals of the first switch module through the inductor. In embodiments of this application, a higher boost ratio can be implemented.

Abstract: A gate voltage magnitude compensation equalization method and circuit for series operation of power switch transistors are provided. A dynamic voltage equalization of series-connected power switch transistors is implemented by using sampling principles where voltages of the power switch transistors are controlled by gate voltage magnitude and unbalanced voltage differentials are converted into unbalanced current differentials of buffer currents. The gate voltage magnitude compensation equalization method and circuit relates to differential control and works in a dynamic voltage change process of the series-connected power switch transistors, without having a negative effect on operation of the power switch transistors under normal operating conditions.

Abstract: A method for a direct current (DC) islanding detection based on positive feedback of a bus voltage at a specific frequency, essentially including three steps: extraction of a specific frequency component of the bus voltage, injection of a disturbance component of the specific frequency, and determination of DC islanding. The extraction of the specific frequency component of the bus voltage and the injection of the disturbance component of the specific frequency constitute a positive feedback mechanism in a power management unit control loop. In a grid-connected mode of a DC grid, the positive feedback mechanism fails due to a control action of a voltage management unit on a bus, and the bus voltage remains stable. In an islanding mode of the DC grid, under an action of the positive feedback mechanism, the power management unit allows the bus voltage to generate a self-excited oscillation at the specific frequency.

Abstract: A gate voltage magnitude compensation equalization method and circuit for series operation of power switch transistors are provided. A dynamic voltage equalization of series-connected power switch transistors is implemented by using sampling principles where voltages of the power switch transistors are controlled by gate voltage magnitude and unbalanced voltage differentials are converted into unbalanced current differentials of buffer currents. The gate voltage magnitude compensation equalization method and circuit relates to differential control and works in a dynamic voltage change process of the series-connected power switch transistors, without having a negative effect on operation of the power switch transistors under normal operating conditions.

Abstract: The present invention discloses a power generation system including a double-fed induction generator, a power converter, and a controller. The double-fed induction generator includes a rotor and a stator coupled to a grid. The power converter includes a rotor side converter coupled to the rotor of the generator, a grid side converter coupled to the grid, and a DC bus coupled between the rotor side converter and the grid side converter. The controller includes a rotor side controller for controlling the rotor side converter and a grid side controller for controlling the grid side converter. The rotor side controller includes a compensator having a transfer function and configured to counter a negative resistance effect of the generator to suppress sub-synchronous oscillations. The present invention further discloses a system for suppressing sub-synchronous oscillations and a method for controlling operation of a power system.

Abstract: The present invention discloses a power generation system including a double-fed induction generator, a power converter, and a controller. The double-fed induction generator includes a rotor and a stator coupled to a grid. The power converter includes a rotor side converter coupled to the rotor of the generator, a grid side converter coupled to the grid, and a DC bus coupled between the rotor side converter and the grid side converter. The controller includes a rotor side controller for controlling the rotor side converter and a grid side controller for controlling the grid side converter. The rotor side controller includes a compensator having a transfer function and configured to counter a negative resistance effect of the generator to suppress sub-synchronous oscillations. The present invention further discloses a system for suppressing sub-synchronous oscillations and a method for controlling operation of a power system.

Abstract: Methods, circuits, apparatus, and systems related to a hybrid driving and controlling circuit are disclosed. In one embodiment, a hybrid driving and controlling circuit in a double power supply system includes first and second power supplies and at least one load, and the circuit can include: (i) a controller coupled to a hybrid switcher that enables energy transfer from the first and second power supplies; (ii) when a determined energy of the first power supply is sufficient, the controller can control the hybrid switcher to transfer energy from the first power supply to the second power supply; and (iii) when the determined energy of the first power supply is insufficient, the controller can control the hybrid switcher to transfer energy from the second power supply to the at least one load.

Abstract: Methods, circuits, apparatus, and systems related to a hybrid driving and controlling circuit are disclosed. In one embodiment, a hybrid driving and controlling circuit in a double power supply system includes first and second power supplies and at least one load, and the circuit can include: (i) a controller coupled to a hybrid switcher that enables energy transfer from the first and second power supplies; (ii) when a determined energy of the first power supply is sufficient, the controller can control the hybrid switcher to transfer energy from the first power supply to the second power supply; and (iii) when the determined energy of the first power supply is insufficient, the controller can control the hybrid switcher to transfer energy from the second power supply to the at least one load.

Abstract: Methods, circuits, apparatus, and systems related to a hybrid driving and controlling circuit are disclosed. In one embodiment, a hybrid driving and controlling circuit in a double power supply system includes first and second power supplies and at least one load, and the circuit can include: (i) a controller coupled to a hybrid switcher that enables energy transfer from the first and second power supplies; (ii) when a determined energy of the first power supply is sufficient, the controller can control the hybrid switcher to transfer energy from the first power supply to the second power supply; and (iii) when the determined energy of the first power supply is insufficient, the controller can control the hybrid switcher to transfer energy from the second power supply to the at least one load.

Abstract: An amplifier comprises a power source, a load network comprising a load and a resonance circuit, an input branch having a first end electrically coupled to the power source and a second end electrically coupled to the load network, and an active switch having one terminal electrically coupled to the second end of the input branch. The input branch including at least one parallel-LC-circuit configured to provide an infinitely large impedance at harmonics of a determined order.

Abstract: Methods, circuits, apparatus, and systems related to a hybrid driving and controlling circuit are disclosed. In one embodiment, a hybrid driving and controlling circuit in a double power supply system includes first and second power supplies and at least one load, and the circuit can include: (i) a controller coupled to a hybrid switcher that enables energy transfer from the first and second power supplies; (ii) when a determined energy of the first power supply is sufficient, the controller can control the hybrid switcher to transfer energy from the first power supply to the second power supply; and (iii) when the determined energy of the first power supply is insufficient, the controller can control the hybrid switcher to transfer energy from the second power supply to the at least one load.

Abstract: An amplifier comprises a power source, a load network comprising a load and a resonance circuit, an input branch having a first end electrically coupled to the power source and a second end electrically coupled to the load network, and an active switch having one terminal electrically coupled to the second end of the input branch. The input branch including at least one parallel-LC-circuit configured to provide an infinitely large impedance at harmonics of a determined order.