An LLC resonant converter comprises, an LLC resonant converter circuit with an output line and an input line. The LLC resonant converter circuit includes a switch array operatively connecting between the input line and the output line. A controller is connected to the input line by a feed forward line and connected to a respective gate of each switch in the switch array. The controller includes machine readable instructions configured to cause the controller to receive feed forward input from the input line and control switching of the switch array with a pulse frequency modulation (PFM) switching pattern to regulate voltage of the output line.

A synchronous average harmonic current controller for a line connected bidirectional resonant power converter results in a harmonic voltage gain closely related to the commanded bridge duty cycles. A primary bridge has its duty cycle set to achieve controlled line power transfer and voltage regulation of a primary bus energy storage capacitor. A secondary bridge circuit has its duty cycle set to achieve voltage regulation of secondary bus energy storage capacitor. A first embodiment uses the independent energy storage elements to achieve power factor correction and low noise regulation using a single stage. A second embodiment uses feedforward duty cycle control to achieve isolated voltage regulation using the well-defined voltage gain resulting from the synchronous average harmonic current controller.

Provided is a converter including: a primary-side switching unit to be connected to a battery; a secondary-side switching unit to be connected to a motor; a transformer provided between the primary-side switching unit and the secondary-side switching unit; and a controller configured to control at least the secondary-side switching unit so as to output a voltage that depends on an output waveform profile of a desired waveform to the motor.

A method for controlling the input voltage frequency of a DC-DC converter includes calculating a control frequency value of the DC-DC converter. If the measured voltage is greater than the upper voltage limit, the control frequency corresponds to the minimum control frequency. If the measured voltage is less than the lower voltage limit, the control frequency corresponds to the maximum control frequency. If the measured voltage is between the upper voltage limit and the lower voltage limit, the control frequency corresponds to an average frequency calculated as a function of the difference between the setpoint voltage value and the measured voltage, upper error values and lower error values, and maximum and minimum control frequency values.

A power converter for detecting oscillation of an output voltage including a switching regulator configured to perform switching so that an inductor is alternatively connected to or isolated from an external power voltage and generate the output voltage by a current that flows through the inductor and an oscillation detector configured to detect oscillation that occurs in the output voltage and output an oscillation detection signal by determining whether the oscillation belongs to an oscillation frequency detection range to be detected by the oscillation detector may be provided.

Circuit embodiments for a switched-capacitor power converter, and/or methods of operation of such a converter, that robustly deal with various startup scenarios, are efficient and low cost, and have quick startup times to steady-state converter operation. Embodiments prevent full charge pump capacitor discharge during shutdown of a converter and/or rebalance charge pump capacitors during a startup period before switching operation by discharging and/or precharging the charge pump capacitors. Embodiments may include a dedicated rebalancer circuit that includes a voltage sensing circuit coupled to an output voltage of a converter, and a balance circuit configured to charge or discharge each charge pump capacitor towards a target steady-state multiple of the output voltage of the converter as a function of an output signal from the voltage sensing circuit indicative of the output voltage. Embodiments prevent or limit current in-rush to a converter during a startup state.

A resonant DC/DC converter which has a first DC link, preferably including a first DC link capacitor; a DC/AC converter which has a first plurality of N>1 converter bridges connected in parallel to the first DC link; each converter bridge comprising a plurality of switches each of which may be switched between a conducting state and a non-conducting state. The resonant DC/DC converter also includes an AC intermediate circuit having an input connected to an output of the DC/AC converter and comprising: a transformer, preferably a medium frequency transformer, having a primary side and a secondary side; the primary side comprising at least one primary winding; a first plurality of N capacitors, wherein for each converter bridge, a different one from the first plurality of capacitors is connected between said converter bridge and the at least one primary winding.

Aspects of hybrid modulation control for DC-to-AC converters are described. In one embodiment, a hybrid modulation pattern is generated. The hybrid modulation pattern separates switch gating control into multiple control regions for a half cycle of the waveform. A first control region modulates according to a first modulation technique and a second control region modulates according to a second modulation technique. The switches of a resonant converter are controlled according to the hybrid modulation pattern to generate the waveform.

This application provides a resonant conversion system, including a controller and a resonant conversion circuit. The resonant conversion circuit includes a high frequency chopper circuit, a resonant cavity, a transformer, and a rectification filter network, and the high frequency chopper circuit includes switches S1 and S2. The controller is configured to: detect a bridge arm midpoint voltage V.sub.SW, and determine based on the V.sub.SW a current threshold signal used to indicate a current threshold; detect a resonant current on a primary side of the transformer, and compare the resonant current with the current threshold signal to control on/off of the switch S1 or S2 based on the second electrical signal, so that the system operates in an inductive mode to ensure zero voltage switching of the switch, while operating in a state close to a capacitive mode to maximize the use of a gain region.

A control method for a bi-directional DC/DC converter. A source terminal transmits electric energy to a destination terminal sequentially through a first rectifier module and a second rectifier module of the converter. The method includes obtaining a first voltage value output by the first rectifier module in a current control cycle, obtaining a second voltage value output by the second rectifier module in the current control cycle, calculating a theoretical voltage control quantity of the bi-directional DC/DC converter in the current control cycle based on a preset reference voltage value and the second voltage value, and setting an actual output voltage of the bi-directional DC/DC converter in a next control cycle based on the theoretical voltage control quantity and the first voltage value.