A system and method using four switches connected in an H-bridge (full bridge) topology within a series-connected FACTS device is disclosed. System and method can be used to bypass a FACTS device. The switches in H-bridge are connected to an alternating current (AC) source allowing for various switching states, and enabling non-monitoring mode, local bypass monitoring mode, low-loss monitoring mode, and diagnostic mode of operation.

A solid-state transformer, a power supply device, and a data center, related to the field of power technologies, to resolve problems of low power density and high manufacturing costs of the solid-state transformer. The solid-state transformer includes a housing and M power conversion units. The M power conversion units include a first power conversion circuit, a high-frequency transformer, and a second power conversion circuit, and the first power conversion circuit is coupled to the second power conversion circuit by using the high-frequency transformer. The housing has an insulation base and a conductive enclosure, the conductive enclosure is sleeved on an outer surface of the insulation base. The insulation base has an accommodating cavity, and in the M power conversion units, at least first power conversion circuits are disposed in the accommodating cavity at intervals, where M is an integer greater than 1.

A solid-state transformer, a power supply device, and a data center, related to the field of power technologies, to resolve problems of low power density and high manufacturing costs of the solid-state transformer. The solid-state transformer includes a housing and M power conversion units. The M power conversion units include a first power conversion circuit, a high-frequency transformer, and a second power conversion circuit, and the first power conversion circuit is coupled to the second power conversion circuit by using the high-frequency transformer. The housing has an insulation base and a conductive enclosure, the conductive enclosure is sleeved on an outer surface of the insulation base. The insulation base has an accommodating cavity, and in the M power conversion units, at least first power conversion circuits are disposed in the accommodating cavity at intervals, where M is an integer greater than 1.

An electronic system sharing power of doorbell includes a switch circuit and an electronic device. The first and second connection terminals of the switch circuit are respectively coupled to two doorbell contacts. The second and third connection terminals of the switch circuit are respectively coupled to two ends of a doorbell. Two power terminals of the electronic device are respectively coupled to two switch contacts. A function circuit of the electronic device is coupled between the two power terminals. In a normal mode, the first connection terminal is conducted to the second connection terminal inside the switch circuit, and the two power terminals are disconnected to each other by a doorbell actuating unit of the electronic device. In a ringing mode, the doorbell actuating unit short-circuits the two power terminals, and the first connection terminal is conducted to the third connection terminal inside the switch circuit.

Various examples are provided for isolated voltage optimization and control. In one example, a stackable isolated voltage optimization module (SIVOM) includes a transformer having a turns ratio between a primary winding and a secondary winding; a switching circuit configured to energize the secondary winding with a voltage provided from the three-phase power system or short the secondary winding; and a connection block configured to couple the switching circuitry to the first phase and a neutral, or to second and third phases of the three-phase power system. In another example, a system includes a SIVOM coupled to each phase of a three-phase power system, where each SIVOM comprises: a transformer and a switching circuit configured to boost or buck a voltage or change a phase angle of the phase coupled to that SIVOM by energizing a secondary winding of the transformer with a voltage provided from the three-phase power system.

Various examples are provided for isolated voltage optimization and control. In one example, a stackable isolated voltage optimization module (SIVOM) includes a transformer having a turns ratio between a primary winding and a secondary winding; a switching circuit configured to energize the secondary winding with a voltage provided from the three-phase power system or short the secondary winding; and a connection block configured to couple the switching circuitry to the first phase and a neutral, or to second and third phases of the three-phase power system. In another example, a system includes a SIVOM coupled to each phase of a three-phase power system, where each SIVOM comprises: a transformer and a switching circuit configured to boost or buck a voltage or change a phase angle of the phase coupled to that SIVOM by energizing a secondary winding of the transformer with a voltage provided from the three-phase power system.

A wireless charging control method applied to a wireless charging control circuit in a terminal device, and the wireless charging control circuit includes a wireless charging receiving coil, the wireless charging receiving coil has at least two operating states, and inductance values of the wireless charging receiving coil in the operating states are different from each other. The method includes: obtaining an induced voltage of the wireless charging receiving coil; and controlling, based on the induced voltage, the wireless charging receiving coil to operate in a corresponding operating state.

The present disclosure relates to a voltage regulation circuit (100). The voltage regulation circuit (100) comprises a transformer (130) having a primary winding (132) having a first end (132A) and a second end (132B), and a first secondary winding (134) having a first end (134A) and a second end (134B), wherein the first end (132A) of the primary winding (132) is configured to receive an input voltage and the second end (132B) of the primary winding (132) is configured to produce an output voltage, wherein the first end (134A) of the first secondary winding (134) is connected to a neutral node (180), wherein the primary winding (132) produces a primary voltage based on the input voltage, and wherein a secondary voltage of the first secondary winding (134) is out-of-phase to the primary voltage of the primary winding (132); and a first switch (160) configured to connect the second end (134B) of the first secondary winding (134) with the second end (132B) of the primary winding (132), wherein, when the first switch (160) is connected, the output voltage is the secondary voltage.

The present disclosure relates to a voltage regulation circuit (100). The voltage regulation circuit (100) comprises a transformer (130) having a primary winding (132) having a first end (132A) and a second end (132B), and a first secondary winding (134) having a first end (134A) and a second end (134B), wherein the first end (132A) of the primary winding (132) is configured to receive an input voltage and the second end (132B) of the primary winding (132) is configured to produce an output voltage, wherein the first end (134A) of the first secondary winding (134) is connected to a neutral node (180), wherein the primary winding (132) produces a primary voltage based on the input voltage, and wherein a secondary voltage of the first secondary winding (134) is out-of-phase to the primary voltage of the primary winding (132); and a first switch (160) configured to connect the second end (134B) of the first secondary winding (134) with the second end (132B) of the primary winding (132), wherein, when the first switch (160) is connected, the output voltage is the secondary voltage.

An electrical assembly includes a converter-based electrical device and a transformer for connecting the converter-based electrical device to an AC electrical network, a first transformer side of the transformer connected to the converter-based electrical device, a second transformer side of the transformer for connection to the AC electrical network, the transformer including a number of taps, the transformer including a tap changer operable to selectively connect to the or each tap to modify a turn ratio of the transformer. The transformer includes a controller configured to selectively operate the tap changer in an AC voltage modification mode, responsive to an abnormal operating state of the electrical assembly, to modify the turn ratio of the transformer so as to modify an AC voltage at the first transformer side.