A cascaded power electronic transformer and a method for controlling the same are provided. The method includes: calculating electrical angles θ.sub.i1 and θ.sub.kps of an s.sup.th transformer and a compensation electrical angle θ.sub.j of a j.sup.th transformer; adding the compensation electrical angle θ.sub.j to the electrical angle θ.sub.kps of the j.sup.th transformer, to obtain a compensated electrical angle θ.sub.kps of the j.sup.th transformer; and calculating a square wave of a bridge arm voltage of each of the m primary converters and the r secondary converters of the s.sup.th transformer based on the electrical angle θ.sub.i1 and the electrical angle θ.sub.kps of the s.sup.th transformer after compensation.

A multilink power converter with reduced winding voltage is disclosed, as well as various applications. In the disclosed embodiments, multiple primary switch modules have their inputs connected in series while using a single transformer winding connected in parallel to the modules' outputs through voltage blocking capacitors. Medium voltage solid-state transformers are presented, including three-phase power converters. Also presented are embodiments utilizing common mode inductors to equalize the currents of the high voltage modules.

A control method of a switching circuit, a control circuit of the switching circuit, and the switching circuit are provided. The switching circuit includes an inductor or a transformer. An operational amplification is performed on an output feedback voltage and a first reference voltage of the switching circuit to obtain a compensation voltage. The compensation voltage controls an on-time of a main switch of the switching circuit. When the current of the inductor or the transformer drops to a threshold, after a time, the main switch is switched from off to on, and the output feedback voltage controls the time. When the output feedback voltage is higher than a first threshold voltage, the compensation voltage is pulled down. When the output feedback voltage is lower than a second threshold voltage, the compensation voltage is pulled up.

The present disclosure discloses a flow battery system and a large-scale flow battery energy storage device. The flow battery system comprises multiple flow batteries; each of the flow batteries comprises a battery pack A, a battery pack B, a battery pack C, and a set of electrolyte circulation system used by the battery pack A, the battery pack B and the battery pack C; the battery pack A, the battery pack B and the battery pack C comprised in each flow battery are independent of each other in the circuit. According to the present disclosure, at least two sets of electrolyte circulation system are saved under the same power scale, such that the system stability is improved while the cost is reduced.

A transformer includes first and second primary windings serially electrically connected in a primary-side series combination. The transformer further includes a secondary winding disposed between the first primary winding and the second primary winding. The transformer further includes first and second shielding windings serially electrically connected in a shielding series combination. The first shielding winding is disposed between the first primary winding and the secondary winding, and the second shielding winding is disposed between the second primary winding and the secondary winding.

Apparatus for power conversion are provided. One apparatus includes a power converter including an input circuit and an output circuit. The power converter is configured to receive power from a source for providing power at a DC source voltage V.sub.S. The power converter is adapted to convert power from the input circuit to the output circuit at a substantially fixed voltage transformation ratio K.sub.DC=V.sub.OUT/V.sub.IN at an output current, wherein V.sub.IN is an input voltage and V.sub.OUT is an output voltage. The input circuit and at least a portion of the output circuit are connected in series across the source, such that an absolute value of the input voltage V.sub.IN applied to the input circuit is approximately equal to the absolute value of the DC source voltage V.sub.S minus a number N times the absolute value of the output voltage V.sub.OUT, where N is at least 1.

An integrated circuit for a power supply circuit configured to generate an output voltage at a target level. The power supply circuit includes a transistor configured to control an inductor current flowing through an inductor. The integrated circuit includes a load detection circuit outputting a detection voltage corresponding to a power consumption of a load and corresponding to an operation mode of the power supply circuit, based on the inductor current, a driver circuit driving the transistor according to the operation mode of the power supply circuit, and a control circuit configured to control the driver circuit to switch the power supply circuit to a second mode upon the detection voltage reaching a first level with a decrease in the power consumption of the load, and to a first mode upon the detection voltage reaching a second level with an increase in the power consumption of the load.

An architecture for a multi-port AC/DC Switching Mode Power Supply (SMPS) with Power Factor Correction (PFC) comprises power management control (PMC) for PFC On/Off Control and Smart Power Distribution, and optionally, a boost follower circuit. For example, in a universal AC/DC multi-port USB-C Power Delivery (PD) adapter, PMC enables turn-on and turn-off of PFC dependent on output port operational status and a combined load of active output ports. A microprocessor control unit (MCU) receives operational status, a voltage sense input and a current sense input for each USB port, computes output power for each USB port, and executes a power distribution protocol to turn-on or turn-off PFC dependent on the combined load from each USB port. Available power may be distributed intelligently to one or more ports, dependent on load. In an example embodiment, turning-off PFC for low load and low AC line input increases efficiency by 3% to 5%.

Various embodiments are directed to a voltage clamp system comprising: a rectifier; a protected node, a reference node, and one or more internal nodes, coupled to the rectifier; a power converter, coupled to the rectifier via the one or more internal nodes; and one or more output nodes coupled to the power converter and configured to couple to a power sink. The rectifier and the power converter are configured to output power via one or more output nodes coupled to the rectifier, and to limit a component of the voltage between the protected node and the reference node.

A crystal that is useful for semiconductor element and a semiconductor element that has enhanced electrical properties are provided. A crystal, including: a corundum structured crystalline oxide, the crystalline oxide including gallium and/or indium, and the crystalline oxide further including a metal of Group 4 of the periodic table. The crystal is used to make a semiconductor element, and the obtained semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.