An energy storage system includes a plurality of bidirectional power converters and a plurality of windings. The plurality of windings shares a magnetic core. A controller transfers energy of a target battery to the magnetic core using a target bidirectional power converter and a target winding at a same time. A voltage of the target battery is greater than those of some or all batteries other than the target battery. As the battery is charged and discharged, the voltage of the battery changes, and the controller only needs to find a new target battery to continue discharging until voltages of all the batteries are equalized, for example, voltage differences between all the batteries are all within a preset voltage range.

A DC/DC converter which includes a first DC link, preferably a first DC link capacitor; a first plurality of N>1 converter bridges connected in parallel to the first DC link; and a transformer, preferably a medium frequency transformer. The transformer includes a primary side and a secondary side, wherein the primary side includes at least one primary winding. The converter further comprises a first plurality of N impedance elements, wherein for each converter bridge, a different one from the first plurality of impedance elements is connected between said converter bridge and the at least one primary winding.

The application provides a power supply device comprising two input ports disposed at a front end of the power supply device; at least one fan disposed behind the two input ports and two isolated power supplies connected respectively to the corresponding one of the two input ports and disposed behind the two input ports and the at least one fan. Each of the isolated power supplies comprises a main power circuit having at least one module, and each module comprises a PCB and a magnetic element and/or switching devices. The at least one module includes an isolated circuit module comprises a transformer having windings formed by laying copper in the PCB and the magnetic core fixed on the PCB. And at least one fan is configured for heat dissipation of the at least one module.

A switching frequency dithering method, a switching circuit and a DC-DC converter. A switching frequency in the switching frequency dithering method dithers up and down at a third switching frequency or between randomly generated target switching frequencies. The embodiments further provide a switching circuit and a DC-DC converter, which can be used to control a clock signal and optimize comprehensive system performance such as improving system efficiency, reducing noise and ripple, suppressing switching harmonics, and reducing electromagnetic radiation.

A power supply can include a main power converter, a standby converter, and control circuitry that operates the standby converter in a constant voltage regulation mode when a load current of the power supply is below a standby threshold and operates the standby converter in a constant current regulation mode when the load current of the power supply is above the standby threshold. The control circuitry can operate the standby converter in a constant voltage regulation mode to produce a voltage higher than a regulated output voltage of the main power converter. The control circuitry can idle the main power converter when a load current of the power supply is below the standby threshold. The standby threshold can correspond to a constant current limit of a constant current control loop of the standby converter. The control circuitry can employ hysteresis to the standby threshold/constant current control loop.

The present disclosure provides a control method, in which charge control is combined with input voltage feedforward control and output current feedforward control. It can be shown that the combination of the charge control with the feedforward control performs better than the combination of the direct frequency control (DFC) with the feedforward control. In particular, the combination of the charge control with the feedforward control has much better load transient response with respect to the load transient response of the combined direct frequency control and feedforward control.

A power converter for a bioelectrochemical system includes first converters each including a direct current terminal for supplying electric current via electrodes of the bioelectrochemical system, and a second converter for supplying energy to the first converters from an external electric power grid. Each first converter includes an electric element for receiving energy from the second converter and a circuitry for converting voltage of the electric element into electrolysis voltage suitable for the bioelectrochemical system. The electric element can be a secondary winding of a transformer or a direct voltage energy storage. Each first converter is galvanically isolated from the other first converters at least when the first mentioned first converter supplies energy to the bioelectrochemical system. Thus, each first converter drives its own electrode pair without disturbing the other first converters.

A power converter includes a primary side circuit, a secondary side circuit, a transformer, and a controller. A primary side of the transformer is connected to the primary side circuit, and a secondary side of the transformer is connected to the secondary side circuit. The primary side circuit includes a resonant circuit. The secondary side circuit is configured to supply electric energy to the transformer. The transformer is configured to supply the electric energy to the primary side circuit. The primary side circuit is configured to convert the electric energy. The controller is connected to the secondary side circuit, and is configured to control, in a control cycle, the secondary side circuit to supply the electric energy to the transformer. Duration of the control cycle is greater than or equal to duration of a resonance cycle of the resonant circuit.

Power line patterns are, together with a ground pattern, provided separately from control line patterns. The power line pattern is formed at first and second major surfaces of a circuit board. When the circuit board is viewed in plan view, the power line pattern and the power line pattern form a line structure in which the power line pattern and the power line pattern are in parallel with and opposite to each other and the power line pattern is positioned under the power line pattern. The circuit board includes a dielectric between the power line pattern and the power line pattern. These together form an equivalent capacitor and the magnetic flux induced by the current flowing through the power line pattern and the magnetic flux induced by the current flowing through the power line pattern cancel each other out.

Controllers and methods for controlling a resonant power converter output voltage include operating the power converter according to a control period comprising an on cycle operation mode for a duration T_on that produces a first voltage Vo1 and an off cycle operation mode for a duration T_off that produces a second voltage Vo2. Vo1 is produced using a first switching frequency for a first selected number of switching cycles corresponding to the on time T_on. The converter output voltage or the converter input and output voltages may be sensed and used to determine the switching frequency during the on cycle operation mode and the duration of the off cycle operation mode. The final output voltage of the power converter is regulated to a selected value based on a ration of (T_on):(T_on+T_off). The controllers and methods may be used with power converters in power delivery devices to accept wide input voltage ranges compatible with devices such as cell phones, tablet computers, and notebook computers.