To reduce energy losses for a welding device when on stand-by and to enable a clean and controlled start of the welding phase, a DC-to-DC converter of the welding device converts an input DC voltage present at an input connection to an output DC voltage present at an output connection. At least one switch element of a branch of the DC-to-DC converter is switched with a switching frequency, and a welding phase is provided for the welding device, during which the switching frequency corresponds to a normal switching frequency. A stand-by phase is provided for the welding device, during which the at least one switch element is switched with a switching frequency corresponding to a stand-by switching frequency which is lower than the normal switching frequency

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.

An embodiment apparatus includes a converter including a plurality of switching elements configured as a bridge circuit connected to an input terminal and having a plurality of bridge arms, wherein a topology of the converter is configured to be switchable to a full-bridge type topology or a half-bridge type topology, and wherein a resonant capacitor is connected to a midpoint between respective ones of the bridge arms, and a controller configured to switch the topology of the converter to the full-bridge type or the half-bridge type by controlling whether the resonant capacitor is activated based on a load current of the converter.

A method for controlling a buck-boost converter includes generating a first threshold voltage with a decreasing voltage level, generating a second threshold voltage with an increasing voltage level, and sensing an inductor current. A signal indicative of the sensed inductor current is compared to the first threshold voltage to control an on time of the high side buck switch and is compared to the second threshold voltage to control an off time of the high side boost switch. Also described is a controller including a compensator responsive to an output voltage feedback signal to generate a compensation voltage and a modulator having a buck signal path coupled to receive the compensation voltage and configured to control an on time of the high side buck switch and a boost signal path coupled to receive the compensation voltage and configured to control an off time of the high side boost switch.

A switching mode power supply with an adaptive setting of a threshold valley voltage. The switching mode power supply decreases a reference auxiliary current when a valley value of a primary switching voltage across a primary switch is smaller than a first threshold valley voltage. And in addition, the switching mode power supply can increase the reference auxiliary current when the valley value of the primary switching voltage is larger than a second threshold valley voltage.

A minimum number of levels required to output a target modulation ratio is determined. Additionally, determining a total number of voltage orders to be controlled among a voltage fundamental wave and harmonics of power converter, comparing the minimum number of levels and the total number of voltage orders to be controlled, and fixing a larger one as a number of switching times in a quarter cycle for the target modulation ratio are performed. Further, when the total number is fixed, a shape of an output voltage is determined, and based on the target modulation ratio and the number of switching times in the quarter cycle, a determination of switching phases is made, in addition to a derivation of the pulse pattern for one cycle by which each output voltage level is used according to the target modulation ratio and the output voltage shape, and the phase is determined.

A voltage regulation system is provided. In the voltage regulation system, a frequency of a clock signal is adjusted and a pulse generator is controlled to output a pulse signal to a switch power stage circuit, to enable the switch power stage circuit to adjust an output voltage and output the adjusted output voltage to the load element. Through the aforementioned configuration, the switch power stage circuit adjusts the output voltage according to the situation of the load element, thus decreasing the power loss of the switch power stage circuit.

A power electronics converter includes a carrier substrate, and a converter commutation cell including a power circuit. The power circuit includes a power semiconductor switching element. The power semiconductor switching element is comprised in a power semiconductor prepackage. The power semiconductor prepackage includes a power semiconductor switching element embedded in a solid insulating material, and an electrical connection extending from a terminal of the power semiconductor switching element through the solid insulating material to an electrical connection side of the power semiconductor prepackage. The power electronics converter includes a heat sink arranged to remove heat from the power semiconductor prepackage. The power electronics converter includes a thermal interface layer arranged between the heat removal side of the power semiconductor prepackage and the heat sink. A thermal conductivity of the thermal interface layer divided by an electrical conductivity of the thermal interface layer is greater than or equal to 1 TW/SK.

An apparatus may include a first switch leg connected between a first input terminal and a first output terminal, the first switch leg comprising serially connected switches. The apparatus may also include a second switch leg connected between a second input terminal and the first output terminal, the second switch leg comprising serially connected switches. The apparatus may further include a third switch leg connected between an input voltage midpoint and the first output terminal. A control circuit may control the first switch leg, the second switch leg and the third switch leg.

A method of controlling a multi-phase power converter having a plurality of power stage circuits coupled in parallel, can include: obtaining a load current of the multi-phase power converter; enabling corresponding power stage circuits to operate in accordance with the load current, such that a switching frequency is maintained within a predetermined range when the load current changes; and controlling the power stage circuits to operate under different modes in accordance with the load current, such that the switching frequency is maintained within the predetermined range when the load current changes.