This application relates to methods and apparatus for driving a transducer with switching drivers. A switching driver has first and second supply node for receiving supply voltages and includes an output bridge stage, a capacitor and a network of switches. The network of switches is operable in different switch states to provide different switching voltages to the output bridge stage. A controller is configured to control the switch state of the network of switches and a duty cycle of output switches of the output bridge stage based on an input signal to generate an output signal for driving the transducer.

A power conversion structure, a power conversion system, a power conversion method, an electronic device including the power conversion structure, and a chip unit are provided. By connecting one switched capacitor series branch between a third terminal of a first switch series branch and a ground terminal, when the power conversion structure needs to operate in a switched capacitor converter mode, a direct current part of a current output from the third terminal of the first switch series branch flows to an inductor, and only an alternating current component flows through an on-state first switch, such that the on-state loss of the first switch can be greatly reduced, and the efficiency of the power conversion structure can be improved.

An apparatus includes a DC-to-AC converter comprising a first output terminal and a second output terminal. The apparatus also includes a DC-to-DC converter comprising a third output. The DC-to-AC converter is configured to receive a DC input voltage from a DC power source, and to produce a first alternating output voltage at the first output terminal, and a second alternating output voltage at the second output terminal. The DC-to-DC converter is configured receive a DC input voltage from the DC power source, and to step down the DC input voltage at the third output.

A power conversion module can include: an i-th level structure comprising 2.sup.i-1 basic units, a second terminal of each basic unit in each level structure respectively connected to first terminals of two basic units in a next level structure, where a first terminal of a first basic unit in a first-level structure is used as a first terminal of the power conversion module; an N-th level structure comprising 2.sup.N-1 balance units, where second terminals of each balance unit are connected as a second terminal of the power conversion module, and second terminals of each basic unit in an (N−1)th level structure are respectively connected to first terminals of two balance units in the N-th level structure; and where each basic unit comprises a switched capacitor circuit, N is a positive integer greater than or equal to 2, i is a positive integer, and 1≤i≤N−1.

A power converter circuit included in a computer system may include multiple devices and a switch node coupled to a regulated power supply node via an inductor. During a first time period, the power converter charges a capacitor, and the couples the capacitor to the switch node during a second time period. During a third time period the power converter couples the switch node to an input power supply node. To maintain constant charge delivered to the load during each time the switch node is coupled to the input power supply node, the duration of the third time period is adjusted based on a voltage level of the input power supply node, a voltage level of the regulated power supply node, a value of the inductor, and the durations of first and second time periods.

The three-level direct current converter includes: a flying capacitor, a plurality of switch groups, a drive circuit, and a control circuit. The control circuit includes at least an on-time generator. When a voltage on the flying capacitor deviates from a half of a power supply voltage, the on-time generator changes a charging current of a capacitor of the on-time generator to adjust an output on-time signal, and outputs the on-time signal to the drive circuit. The drive circuit generates a drive pulse signal based on the on-time signal to drive switch statuses of the plurality of switch groups, to adjust charging time and discharging time of the flying capacitor, where an absolute value of a difference between the voltage on the flying capacitor and the half of the power supply voltage is less than or equal to a preset threshold.

An inverter includes an upper unit comprises a first switch, a second switch and a third switch, wherein during a first half of a cycle of the inverter, the second switch is turned on before and turned off after the third switch, a lower unit comprising a fourth switch, a fifth switch and a sixth switch, wherein during a second half of the cycle of the inverter, the fifth switch is turned on before and turned off after the sixth switch, a flying capacitor connected between the upper unit and the lower unit, and a filter connected to a common node of the upper unit and the lower unit.

A converter includes a DC bus, a first DC-DC converter, a second DC-DC converter, and a plurality of circulating current suppression circuits. The first DC-DC converter is coupled to the DC bus and includes a first plurality of switches. The second DC-DC converter is coupled to the DC bus in parallel with the first DC-DC converter. The second DC-DC converter includes a second plurality of switches. The plurality of circulating current suppression circuits are coupled to the DC bus and are further respectively coupled to the first DC-DC converter and the second DC-DC converter. Each of the plurality of circulating current suppression circuits has a resonant frequency at or around a switching frequency for the first and second pluralities of switches. The plurality of circulating current suppression circuits is configured to suppress current at or around the switching frequency and pass at least direct current.

Systems and methods of this disclosure use low voltage energy storage devices to supply power at a medium voltage from an uninterruptible power supply (UPS) to a data center load. The UPS includes a low voltage energy storage device (ultracapacitor/battery), a high frequency (HF) bidirectional DC-DC converter, and a multi-level (ML) inverter. The HF DC-DC converter uses a plurality of HF planar transformers, multiple H-bridge circuits, and gate drivers for driving IGBT devices to generate a medium DC voltage from the ultracapacitor/battery energy storage. The gate drivers are controlled by a zero voltage switching (ZVS) controller, which introduces a phase shift between the voltage on the primary and secondary sides of the transformers. When the primary side leads the secondary side, the ultracapacitor/battery discharges and causes the UPS to supply power to the data center, and when the secondary side leads the primary side, power flows from the grid back to the UPS, thereby recharging the ultracapacitor/battery.

A power converter for transforming electrical power between direct current (DC) power and alternating current (AC) power is provided, as well as a controller therefor and associated methods and systems. The power converter comprises: a first set of packed U-cell converters connectable between a first common connection point and a first terminal of an external circuit, the first common connection point connecting to a first terminal of a DC circuit element; a second set of packed U-cell converters connectable between a second common connection point and a second, opposite terminal of the external circuit, the second common connection point connecting to a second, opposite terminal of the DC circuit element; and a controller configured for controlling the operation of the first and second sets of packed U-cell converters.