Systems and methods for operating a light-emitting diode (LED) driver circuit are provided. Aspects include providing an interleaved boost converter including a first boost converter and a second boost converter, the second boost converter interleaved with the first boost converter, operating a first switching element to control a first boost convertor in the LED driver circuit, wherein the first boost convertor is in an ON state responsive to the first switching element being in an ON state, operating a second switching element to control a first boost convertor in the LED driver circuit, wherein the second boost convertor is in an ON state responsive to the first switching element being in an ON state, providing a set of LEDs, wherein the interleaved boost converter provides a step-up voltage to the set of LEDs.

Systems and methods for operating a light-emitting diode (LED) driver circuit are provided. Aspects include providing an interleaved boost converter including a first boost converter and a second boost converter, the second boost converter interleaved with the first boost converter, operating a first switching element to control a first boost convertor in the LED driver circuit, wherein the first boost convertor is in an ON state responsive to the first switching element being in an ON state, operating a second switching element to control a first boost convertor in the LED driver circuit, wherein the second boost convertor is in an ON state responsive to the first switching element being in an ON state, providing a set of LEDs, wherein the interleaved boost converter provides a step-up voltage to the set of LEDs.

A current mode switching regulator circuit and operating method includes a variable duty cycle power switch controller, a voltage feedback loop that provides a feedback signal based on the output voltage, a current feedback loop that provides a current sense signal based on the output current, and an offset circuit having an external signal input and coupled to the current feedback loop. The power switch controller controls the switching regulator circuit to generate an output voltage and an output current. The offset circuit is configured to provide an offset output control signal, independently of the voltage feedback loop, to control the power switch controller so as to vary a duty cycle of the power switch controller based on the current sense signal and an external offset signal applied to the external signal input.

A current mode switching regulator circuit and operating method includes a variable duty cycle power switch controller, a voltage feedback loop that provides a feedback signal based on the output voltage, a current feedback loop that provides a current sense signal based on the output current, and an offset circuit having an external signal input and coupled to the current feedback loop. The power switch controller controls the switching regulator circuit to generate an output voltage and an output current. The offset circuit is configured to provide an offset output control signal, independently of the voltage feedback loop, to control the power switch controller so as to vary a duty cycle of the power switch controller based on the current sense signal and an external offset signal applied to the external signal input.

The present invention provides a method of MMC for HVDC. According to the present invention, there is provided a redundancy control method of an MMC for HVDC, wherein the MMC includes multiple converter arms each has multiple submodules in operation and redundancy modules for spares, the method including: checking whether a breakdown of a submodule in operation of a first converter arm among the multiple converter arms occurs in a case where the all redundancy modules of the first converter arm are applied in operation; and lowering an output voltage of each submodule of other converter arms in such a manner that a DC link voltage of each of the other converter arms is controlled to be equal to a DC link voltage of the first converter arm when the breakdown of the submodule of the first converter arm occurs.

The present invention provides a method of MMC for HVDC. According to the present invention, there is provided a redundancy control method of an MMC for HVDC, wherein the MMC includes multiple converter arms each has multiple submodules in operation and redundancy modules for spares, the method including: checking whether a breakdown of a submodule in operation of a first converter arm among the multiple converter arms occurs in a case where the all redundancy modules of the first converter arm are applied in operation; and lowering an output voltage of each submodule of other converter arms in such a manner that a DC link voltage of each of the other converter arms is controlled to be equal to a DC link voltage of the first converter arm when the breakdown of the submodule of the first converter arm occurs.

A method for charging an energy storage element of a vehicle using a charging apparatus which provides a charging current (I.sub.L) and a charging voltage (U) at an operating point. The charging apparatus has a plurality of energy supply modules connected in parallel, having the following method steps: in an optimization step, a distribution of the charging current (I.sub.L) to the energy supply modules connected in parallel, in the case of which the charging apparatus has a maximum overall efficiency, is respectively determined for a plurality of predefined operating points; in a charging step which follows the optimization step, a distribution of the charging current (I.sub.L) to the individual energy supply modules of the charging apparatus, in the case of which the charging apparatus has a maximum overall efficiency, is selected on the basis of a predefined charging current (I.sub.L) and a predefined charging voltage (U).

Described examples include DC to DC converters and systems with switching circuitry formed by four series-connected switches, inductors connected between the ends of the switching circuitry and corresponding output nodes, and with a flying capacitor coupled across interior switches of the switching circuitry and a second capacitor coupled across the ends of the switching circuitry. A control circuit operates the switching circuit to control a voltage signal across the output nodes using a first clock signal and a phase shifted second clock signal to reduce output ripple current and enhance converter efficiency using valley current control. The output inductors are wound on a common core in certain examples.

The present invention provides a method of MMC for HVDC. According to the present invention, there is provided a redundancy control method of an MMC for HVDC, wherein the MMC includes multiple converter arms each has multiple submodules in operation and redundancy modules for spares, the method including: checking whether a breakdown of a submodule in operation of a first converter arm among the multiple converter arms occurs in a case where the all redundancy modules of the first converter arm are applied in operation; and lowering an output voltage of each submodule of other converter arms in such a manner that a DC link voltage of each of the other converter arms is controlled to be equal to a DC link voltage of the first converter arm when the breakdown of the submodule of the first converter arm occurs.

The present invention provides a method of MMC for HVDC. According to the present invention, there is provided a redundancy control method of an MMC for HVDC, wherein the MMC includes multiple converter arms each has multiple submodules in operation and redundancy modules for spares, the method including: checking whether a breakdown of a submodule in operation of a first converter arm among the multiple converter arms occurs in a case where the all redundancy modules of the first converter arm are applied in operation; and lowering an output voltage of each submodule of other converter arms in such a manner that a DC link voltage of each of the other converter arms is controlled to be equal to a DC link voltage of the first converter arm when the breakdown of the submodule of the first converter arm occurs.