A power supply includes a boost converter, a capacitor, a step-down converter and a control unit. The boost converter, when activated, converts an input voltage into a boost voltage. The capacitor has a bulk voltage which is equal to the boost voltage when the boost converter is activated. The step-down converter converts the boost voltage into a step-down voltage for output. While the boost converter is deactivated, the control unit samples the input voltage and the bulk voltage, calculates an estimated value, and determines a calibration parameter. While the boost converter is activated, the control unit calculates a calibration value for enabling the boost converter to convert the input voltage with reference to the calibration value.

A power supply includes a boost converter, a capacitor, a step-down converter and a control unit. The boost converter, when activated, converts an input voltage into a boost voltage. The capacitor has a bulk voltage which is equal to the boost voltage when the boost converter is activated. The step-down converter converts the boost voltage into a step-down voltage for output. While the boost converter is deactivated, the control unit samples the input voltage and the bulk voltage, calculates an estimated value, and determines a calibration parameter. While the boost converter is activated, the control unit calculates a calibration value for enabling the boost converter to convert the input voltage with reference to the calibration value.

Power conversion systems, methods and precharge systems are disclosed to charge a DC bus capacitor, including thyristors and reverse diodes coupled in AC circuit paths between AC input lines and a rectifier, a precharge resistor coupled in one or more of the AC circuit paths, and a controller to turn all the thyristors off to allow the DC bus capacitor to charge through the precharge resistor, and to turn all the thyristors on when the DC bus voltage reaches a non-zero threshold value.

The present disclosure provides a capacitor-less AC/DC converter power supply system. The power supply system includes one or more rectifier cells having inductive and synchronous elements, and removing any capacitive filter elements thus ensuring a very high Mean Time Before Failure (MTBF) on the rectifier stage. The output voltage and current generated by the one or more inductive cells is a DC signal having a ripple amount dependent upon the number of cells implemented.

An apparatus for generating electric power from the motion of a vehicle according to the disclosure includes: a magnetic fluid storage unit in which a magnetic fluid is stored and from which the magnetic fluid is discharged by a pressing force of the vehicle; a pipe unit through which the magnetic fluid discharged from the magnetic fluid storage unit moves; and an induction coil unit arranged to surround a circumference of the pipe unit so that an induced electromotive force is generated when the magnetic fluid moves.

An apparatus for generating electric power from the motion of a vehicle according to the disclosure includes: a magnetic fluid storage unit in which a magnetic fluid is stored and from which the magnetic fluid is discharged by a pressing force of the vehicle; a pipe unit through which the magnetic fluid discharged from the magnetic fluid storage unit moves; and an induction coil unit arranged to surround a circumference of the pipe unit so that an induced electromotive force is generated when the magnetic fluid moves.

A voltage source converter includes at least one limb connected between DC terminals, the or each limb including: a phase element including switching elements to interconnect a DC electrical network and an AC electrical network; an auxiliary sub-converter configured to be controllable to act as a waveform synthesizer to modify a first DC voltage presented to the DC electrical network; and a tertiary sub-converter connected in parallel with the electrical block and controllable to act as a waveform synthesizer to modify a second DC voltage presented to a DC side of the phase element, the tertiary sub-converter (39) including at least one energy storage device. The voltage source converter includes a controller configured to selectively control the or each tertiary sub-converter to synthesize at least one tertiary voltage component so as to transfer energy to or from that tertiary sub-converter and thereby regulate an energy level of that tertiary sub-converter.

Provided is a buck converter. The converter includes a power switch configured to receive and switch an input voltage and convert the input voltage into an output voltage, and a switch control circuit configured to generate a signal having a frequency synchronized with the input voltage, compensate for the signal by using an edge threshold voltage in an edge area of the signal according to at least one of a load state and the input voltage, and control switching of the power switch by using a result of comparing the signal with a band voltage corresponding to the output.

The application provides a cascade system distributed control method and device. The method including: taking an output of a closed-loop control for regulating an AC current of the power module as a reference value of a bridge arm voltage; according to the reference value of the bridge arm voltage to obtain an amplitude of the bridge arm voltage, taking the amplitude of the bridge arm voltage as a feedback signal, and after closed-loop control and regulation together with the AC current of the power module, adjusting the reference value of the bridge arm voltage; and controlling the bridge arm voltage according to the reference value of the bridge arm voltage, wherein in at least one working mode of the cascade system, a change of parameters reflecting an active current has a monotonic relation with a change of the amplitude of the bridge arm voltage.

The application provides a cascade system distributed control method and device. The method including: taking an output of a closed-loop control for regulating an AC current of the power module as a reference value of a bridge arm voltage; according to the reference value of the bridge arm voltage to obtain an amplitude of the bridge arm voltage, taking the amplitude of the bridge arm voltage as a feedback signal, and after closed-loop control and regulation together with the AC current of the power module, adjusting the reference value of the bridge arm voltage; and controlling the bridge arm voltage according to the reference value of the bridge arm voltage, wherein in at least one working mode of the cascade system, a change of parameters reflecting an active current has a monotonic relation with a change of the amplitude of the bridge arm voltage.