A converter module is provided with a first power delivery circuit, a second power delivery circuit, and a controller. The first power delivery circuit supplies current from a first direct current (DC) source to a resonant stage in a first direction. The first power delivery circuit comprises at least two first switches. The second power delivery circuit supplies the current from the first DC source to the resonant stage in a second direction, opposite the first direction. The controller includes memory, and a processor that is programmed to: enable the first power delivery circuit and the second power delivery circuit alternately to provide power as a periodic waveform to the resonant stage; and disable the at least two first switches individually in a sequence to generate a phase shift in the periodic waveform and to disable the first power delivery circuit.

Control of a resonant power converter using switch paths during power-up is described herein. During power-up, a first switch path sinks current away from a resonant capacitor while a second switch path sources current to a high-side capacitor. In this way the high-side capacitor may predictably charge to sufficient bootstrap voltage for steady state operation. Additionally, a third switch path may control current to a low-side capacitor.

An integrated circuit for a power supply circuit including a transformer having a primary coil, a secondary coil, and an auxiliary coil, and a transistor configured to control a current flowing through the primary coil. The integrated circuit includes a first terminal receiving a power supply voltage corresponding to a voltage from the auxiliary coil; a second terminal receiving a feedback voltage corresponding to an output voltage; a third terminal receiving a voltage corresponding to a current flowing through the transistor when the transistor is on; a determination circuit determining whether a detection circuit configured to detect a voltage generated in the auxiliary coil is coupled between the third terminal and the auxiliary coil; and a switching control circuit controlling switching of the transistor based on the voltages at the second and third terminals and a determination result of the first determination circuit.

In an embodiment, a method for operating an ACF converter includes: turning on a low-side transistor that is coupled between a primary winding of a transformer and a reference terminal to cause a forward current to enter the primary winding, turning off the low-side transistor; after turning off the low-side transistor, turning on a high-side transistor that is coupled between the primary winding and a clamp capacitor to cause a reverse current to flow through the primary winding; and after turning on the high-side transistor, when an overcurrent of the reverse current is not detected, keeping the high-side transistor on for a first period of time, and turning off the high-side transistor after the first period of time, and when the overcurrent of the reverse current is detected, turning off the high-side transistor without keeping the high-side transistor on for the first period of time.

An electronic appliance such as a low harmonic drive, an active rectifier, a grid converter or any active front end or grid converter with an LCL filter. The converter is a two-level, a three-level or a multilevel inverter. The electronic appliance includes an LCL filter on a grid side of the electronic appliance and an active front end rectifier provided on a load side of the electronic appliance. The LCL filter includes grid side inductors and an active front end rectifier is connected to the LCL filter. A method for damping a corresponding electronic appliance is also disclosed.

An electronic appliance such as a low harmonic drive, an active rectifier, a grid converter or any active front end or grid converter with an LCL filter. The converter is a two-level, a three-level or a multilevel inverter. The electronic appliance includes an LCL filter on a grid side of the electronic appliance and an active front end rectifier provided on a load side of the electronic appliance. The LCL filter includes grid side inductors and an active front end rectifier is connected to the LCL filter. A method for damping a corresponding electronic appliance is also disclosed.

An apparatus comprises a first power supply, a second power supply, and a controller. The first power supply supplies a first input voltage to power a first input of a load over a first circuit path. The second power supply supplies a second input voltage to power a second input of the load over a second circuit path. The controller controls connectivity of the first circuit path to the second circuit path as a function of the first input voltage and the second input voltage during at least ramp up or ramp down of either or both of the first input voltage and the second input voltage.

An auxiliary power supply device for an inverter with a plurality of power modules connected in parallel is disclosed. The auxiliary power supply device includes: a plurality of soft-start circuits, each coupled to a DC port of a corresponding power module; a plurality of distributed auxiliary power supplies, each having an input terminal coupled to the DC port of the corresponding power module; and a centralized auxiliary power supply having an input terminal coupled to an AC side of the inverter, and an output terminal coupled to a DC side of the inverter. By replacing auxiliary power supplies on the AC sides of all power modules with the centralized auxiliary power supply and omitting soft-start circuits on the AC sides of all power modules, the present invention improves system performance in cost, volume, loss, and electromagnetic compatibility.

An auxiliary power supply device for an inverter with a plurality of power modules connected in parallel is disclosed. The auxiliary power supply device includes: a plurality of soft-start circuits, each coupled to a DC port of a corresponding power module; a plurality of distributed auxiliary power supplies, each having an input terminal coupled to the DC port of the corresponding power module; and a centralized auxiliary power supply having an input terminal coupled to an AC side of the inverter, and an output terminal coupled to a DC side of the inverter. By replacing auxiliary power supplies on the AC sides of all power modules with the centralized auxiliary power supply and omitting soft-start circuits on the AC sides of all power modules, the present invention improves system performance in cost, volume, loss, and electromagnetic compatibility.

An auto calibration method used in switching converters with constant on-time control. The auto calibration method includes: generating a periodical clock signal with a predetermined duty cycle; providing a first voltage and a second voltage to an on-time control circuit to generate an on-time control signal based on the first and second voltage; providing the clock signal and on-time control signal to a logic circuit to generate a switch control signal based on the clock signal and on-time control signal; comparing the duty cycle of the switch control signal with the duty cycle of the clock signal to adjust a calibration code signal; and adjusting circuit parameters of the on-time control circuit in accordance with the calibration code signal.