A power supply system comprises: a switched-capacitor converter, a multi-tapped autotransformer, and an output stage. The multi-tapped autotransformer includes multiple primary windings. The switched-capacitor converter includes multiple circuit paths coupled to the primary windings. For example, a first circuit path includes a first capacitor; a second circuit path includes a second capacitor. The power supply further includes a controller that controllably switches an input voltage to the first circuit path and the second circuit path, conveying energy to the primary windings of the multi-tapped autotransformer. The output stage of the power supply is coupled to receive energy from a combination of the first primary winding and the second primary winding of the multi-tapped autotransformer. Via the received energy, the output stage produces an output voltage that powers a load.

An inductor device includes at least two wires and at least two switches. Each of the at least two wires includes an opening, and the openings are disposed correspondingly to each other. One of the at least two switches is coupled to two terminals of the opening of one of the at least two wires. Another one of the at least two switches is coupled to one terminal of the opening of the one of the at least two wires and one terminal of the opening of another one of the at least two wires in an interlaced manner. If the one of the at least two switches is turned on, one of the at least two wires forms an inductor; if another one of the at least two switches is turned on, both of the at least two wires form the inductor.

A high-voltage lead structure for a three-dimensional wound core of a transformer that includes a three-dimensional wound core spliced by three rectangular single frames, and A-phase, B-phase and C-phase windings. The three-dimensional wound core includes three core legs, an upper iron yoke and a lower iron yoke. The upper iron yoke and the lower iron yoke of the three-dimensional wound core are triangular structures respectively. The A-phase, B-phase and C-phase windings are correspondingly arranged in the three core legs. Each single-phase winding includes an internal low-voltage winding and an external high-voltage winding. High-voltage windings of the A-phase, the B-phase and the C-phase are jointly connected to a tap switch through lead-out wires. The tap switch is located outside the triangular structure of the upper iron yoke and is arranged in a vertical extension line of a midpoint between the A-phase and C-phase windings.

A power supply system comprises: a switched-capacitor converter, a multi-tapped autotransformer, and an output stage. The multi-tapped autotransformer includes multiple primary windings. The switched-capacitor converter includes multiple circuit paths coupled to the primary windings. For example, a first circuit path includes a first capacitor; a second circuit path includes a second capacitor. The power supply further includes a controller that controllably switches an input voltage to the first circuit path and the second circuit path, conveying energy to the primary windings of the multi-tapped autotransformer. The output stage of the power supply is coupled to receive energy from a combination of the first primary winding and the second primary winding of the multi-tapped autotransformer. Via the received energy, the output stage produces an output voltage that powers a load.

Techniques are disclosed implementing a tunable transformer with additional taps in at least one of the three coils. The tunable transformer enables the resonant frequency within RF transceiver matching networks to be adjusted without substantially impacting the output power at resonance. The tunability of the transformer is partially driven by the insertion of additional coils within the transformer, which are selectively switched and may be further coupled with a tunable capacitance. The tunability of the transformer is further driven via the use of at least one multi-tap transformer coil, which allows electronic components to be coupled to different coil taps to thereby facilitate an adjustable DC inductance. Doing so counteracts changes in mutual inductance between the non-switched coils, and facilitates the stabilization of output power with shifts in resonant frequency.

An assembly for connection to a high-voltage system has multiple single-phase transformers each having a transformer tank which is filled with a fluid and in which a core with at least one winding is situated. At least some of the windings of the single-phase transformers are connected to one another, forming a neutral point. A short-circuit voltage curve or impedance of the assembly can be adapted to different requirements. The windings are each connected to the neutral point via a switchover unit and a choke winding. The choke winding has multiple tappings, and the switchover unit is configured to select the tapping via which the winding in question is connected to the neutral point.

The power-handling capability and reliability of a transformer or a double-wound alternating current motor or generator is improved by a connected switching network which changes the effective numbers of turns and effective wire size of the windings (primary & secondary for a transformer or stator and rotor for a motor or generator) synchronously during each quarter-cycle of the applied or generated voltage.

Electronic systems for controlling submersible pumps are provided herein. In certain configurations, a pump system includes three or more submersible pumps used for pumping fluid from a reservoir, sensors used for generating sense signals indicating a fluid level of the reservoir, and a control circuit for selectively activating the pumps based on the sense signals so as to control pumping of fluids from the reservoir. In certain implementations, the control circuit is operable in a plurality of user-selectable operating modes associated with different pump activation sequences in response to the fluid level of the reservoir rising.

An on-load tap-changer provides uninterrupted diverter switch operation between different winding taps of a tap-changing transformer. The on-load tap-changer includes: a flange module; and a union nut. The on-load tap-changer is configured to be fastened to the tap-changing transformer by the union nut and the flange module.

Disclosed is a three-dimensional wound core transformer high-voltage lead structure, comprising a three-dimensional wound core (1) formed by three rectangular single frames, and A-phase, B-phase and C-phase windings (2), wherein the three-dimensional wound core comprises three core posts and an upper yoke and a lower yoke, the upper yoke and lower yoke of the three-dimensional wound core are respectively triangular structures, the A-phase, B-phase and C-phase windings are correspondingly arranged on the three core posts, each winding comprises an internal low-voltage winding and an external high-voltage winding, and the A-phase, B-phase and C-phase high-voltage windings are jointly connected via a lead-out line (3) to a tap changer (4); and characterised in that the tap changer is located outside the triangular structure of the upper yoke, and on a vertical extension line at a mid-point between the A-phase and the C-phase windings. The high-voltage lead structure means that the lead length is greatly shortened, few lead clamps are needed, and lead to ground discharge points are significantly reduced, improving the reliability of transformer products.