Abstract: A system comprises a five-level rectifier configured to be connected with an ac power source, wherein the five-level rectifier comprises a first boost apparatus and a first buck apparatus configured to operate in a first half cycle of the ac power source, and a second boost apparatus and a second buck apparatus configured to operate in a second half cycle of the ac power source and a five-level inverter connected to the five-level rectifier.

Abstract: A power supply circuit which can suppress current surges comprises a first switch unit, a first control unit, a second switch unit, and a second control unit. The first switch unit is coupled between a voltage input terminal and a load, the load comprising a capacitor. The second switch unit is coupled between the voltage input terminal and the load. The second control unit turns on the second switch unit to charge the capacitor to a predetermined voltage before the first control unit controls the first switch unit to turn on. The second control unit controls the second switch unit to turn off when a voltage of the capacitor is greater than the predetermined voltage, and the first control unit controls the first switch unit to then turn on to supply power to the load.

Abstract: The present invention provides a power limiting circuit for inverter device and an inverter device, which pertains to the technical field of power source inverting. The inverter device comprises a first logic judging circuit for comparing an input current of an inverter circuit with a first preset current threshold and outputting a first signal when said input current is larger than the first preset current threshold; and a shunt circuit for shunting a portion of the input current of the inverter circuit when receiving said first signal; wherein, the shunt circuit comprises a shunt resistance and a first controllable switch, the shunt resistance and the first controllable switch are connected in series and then parallel-connected to input ends of the inverter circuit, a control end of the first controllable switch is connected to an output end of the first logic judging circuit for controlling the first controllable switch to be connected when receiving said first signal.

Abstract: The flyback converter generally has a capacitive divider operatively connectable to a voltage source for receiving an input voltage, the capacitive divider having a plurality of capacitive devices connected in series from one another; a transformer having a plurality of primary windings inductively coupled to at least one secondary winding, each one of the primary windings of the transformer being connected in parallel to a corresponding one of the capacitive devices of the capacitive divider via a switching device, each of the at least one secondary winding being connected to a forwardly biased and capacitive circuit connectable to an output load; and a controller connected to each one of the switching devices for operating the flyback converter to power the output load with the voltage source.

Abstract: An AC-DC converter that converts an AC power supply voltage to a DC output voltage of a prescribed magnitude with power factor regulation includes a voltage regulation unit; an instantaneous value command calculator; a current regulation unit; an output voltage command calculator; a drive signal generator that generates a drive signal for a semiconductor switching device from the output voltage command and a carrier signal, the driving signal being provided to the semiconductor switching device so as to switch the semiconductor switching device ON and OFF; and a rectified voltage estimation unit that that derives an estimated value of a rectified voltage obtained by rectifying the AC power supply voltage from the output voltage command without actually detecting a rectified voltage, for providing to the instantaneous value command calculator and the output voltage command calculator.

Abstract: An inductor; a first switch having a first side connected to a first voltage source (VS1); a second switch having a first side connected to a second side of the first switch (2SS1), and a second side connected to a first side of the inductor (1SI); a third switch having a first side connected to the 1SI; a fourth switch having a first side connected to a second side of the third switch (2SS3), and a second side connected to a second voltage source (VS2); a fifth switch having a first side connected to the 1SI, and a second side connected to the VS1 and/or the VS2; a first capacitor having a first side connected to the 2SS1, and a second side connected to the 2SS3; and a second capacitor having a first side connected to a second side of the inductor, and a second side connected to the VS2.

Abstract: A single phase five-level inverter topology comprising a half-bridge inverter circuit with a floating capacitor which outputs five mutually different voltage levels including zero, wherein both the system cost and the size is reduced, the leakage current is eliminated substantially and high efficiency is achieved by using five-level half-bridge structure with only one AC filtering inductor. A three-phase five-level inverter topology wherein the voltage utilization is twice that of the present three-phase five-level half-bridge inverter under the same operating conditions; the AC filtering inductance is smaller than that of the three-level half-bridge inverter; the DC link mid-point voltage can be balanced without additional circuitry.

Abstract: An electrical system includes a sensing arrangement coupled to an electrical grid interface to measure an electrical characteristic of the electrical grid interface, a power conversion module having an output coupled to the electrical grid interface, and a control module coupled to the sensing arrangement and the power conversion module. The control module determines a reference value for the electrical characteristic, identifies an islanding condition based on a difference between a value for the electrical characteristic and the reference value, determines a target output value for the power conversion module based on the difference, and in response to the islanding condition, operates the power conversion module to provide the target output value for the electrical characteristic at the output. The target output value reduces the difference while a connection arrangement is being opened to achieve islanding.

Abstract: The present invention is concerned with a four-level voltage source converter topology including two intermediate converter branches connecting two intermediate voltage levels to a load terminal, and including a interconnect switch coupling the two intermediate branches. The interconnect switch replaces two controlled switches present in corresponding four-level prior art topologies. The four-level converter thus requires, for a full bidirectional implementation, only five active switches. The reduced number of active switches/gate drivers and the four available output voltage levels make this solution interesting for lower cost power electronics with improved reliability, good power quality and minimized filtering requirement.

Abstract: A switching power supply apparatus, including a power converting device body configured to switch DC input power through a first switching element to thereby store the DC input power in an inductor, and to transfer the stored power to an output capacitor through a second switching element by use of resonance of the inductor, a control circuit configured to drive the first and second switching elements to alternately turn ON or OFF the two switching elements, to thereby resonate the inductor, and an overload detecting circuit configured to detect a load state of the power converting device body based on a peak value or an effective value of a resonance voltage generated from the resonance of the inductor, to thereby control operation of the control circuit.

Abstract: A power conversion device in which a plurality of converter cells are connected in series with one another. The converter cells each include two or more semiconductor devices, an energy storage element and a bypass element including a constituent element for setting the bypass element to be close-circuited by detecting abnormality of a converter cell, and including a constituent element for controlling, among the semiconductor devices, a semiconductor device connected in parallel with the bypass element to set in a turn-on state, at the same time when the bypass element is set close-circuited or in advance of its close circuit.

Abstract: A buck converter includes a power switch having one end to which an input voltage is transferred, a synchronous switch connected between the other end of the power switch and the ground, an inductor having an end connected to the other end of the power switch, and a switch control circuit configured to calculate a zero voltage delay time based on at least an ON time of the power switch and a delay time. The delay time is determined based on the inductor and parasitic capacitors of the power switch and the synchronous switch.

Abstract: A switching regulator includes a first switch; a second switch coupled between the first switch and ground; an inductor coupled to a common node between the first and second switches; a capacitor coupled between the inductor and ground; a controller receiving a disable signal, and generating first and second control signals respectively for the first and second switches; and a crossing detector comparing an auxiliary voltage at the common node with a negative reference voltage to generate a comparison signal, and generating the disable signal based on the first control signal and the comparison signal. The second control signal switches into an inactive state upon the disable signal indicating a reference-crossing of the auxiliary voltage.

Abstract: A three-level power converter includes a first module housing a vertical arm forming a three-level power conversion circuit; a second module disposed adjacent to the first module and housing an intermediate arm forming the three-level power conversion circuit; high-potential and low-potential connecting terminal boards each extending vertically, and having a lower end connected to connecting terminals on an upper surface of the first module, and an upper end provided with an external connecting end; and a flat intermediate-potential connecting terminal board extending vertically, and having a lower end connected to connecting terminals on an upper surface of the second module, and an upper end provided with an external connecting end. The high-potential, low-potential, and intermediate-potential connecting terminal boards are stacked close to and parallel to one another. Each of the external connecting ends is connected to a corresponding terminal of a DC capacitor.

Abstract: In an electric power conversion device which performs power conversion between multiphase AC and DC, a first converter cell of a first arm for each phase of a power converter includes: a capacitor; a Leg A having upper and lower arms having switching elements; and a Leg B having upper and lower arms one of which has a switching element and the other of which has only a diode, and a second converter cell of a second arm includes: a capacitor; and a Leg Aa having upper and lower arms having switching elements. A control device has a steady mode and a protection mode. When short-circuit between DC terminals of the power converter is detected, the control device switches from the steady mode to the protection mode, turns off all the switching elements of the first converter cell of the first arm, and controls the second converter cell of the second arm so as to perform reactive power compensation operation.

Abstract: Disclosed is an on-load voltage regulation tap switch for a transformer, comprising a main switch group, a switch contact protection branch and a switch control circuit, wherein the main switch group comprises a plurality of switch contacts, one end of the switch group is connected to a corresponding transformer winding tap, and the other end of the switch group is connected in parallel and is then connected to a power source; the switch contact protection branch is a series circuit formed by a plurality of groups of diodes and auxiliary switch contacts, and is respectively connected to both ends of a corresponding main switch in parallel; and the switch control circuit is composed of a power source, a single chip microcomputer and a peripheral circuit, and controls all of the main switches and auxiliary switches to act in a certain time sequence to complete the switching of the transformer windings.

Abstract: A frequency jittering control circuit includes a frequency jittering circuit, a feedback compensation circuit, a comparator and a control circuit. The frequency jittering circuit generates a frequency jittering signal. The feedback compensation circuit generates a feedback compensation signal in response to the frequency jittering signal and an output signal. The comparator outputs a comparison output signal according to the feedback compensation signal and an oscillation signal. The control circuit outputs a frequency jittering control signal for switching a main switch in a power supply apparatus, according to the comparison output signal, such that the power supply apparatus correspondingly generates the output signal.

Abstract: A method and apparatus for providing multi-phase power. In one embodiment, the apparatus comprises a cycloconverter controller for determining a charge ratio based on a reference waveform; and a cycloconverter, coupled to the cycloconverter controller and to a multi-phase AC line, for selectively coupling an alternating current to each line of the multi-phase AC line based on the charge ratio.

Abstract: A control circuit reduces switching loss by periodically stopping switching elements, and reduces the difference between the time for which positive switching elements are in on state and the time for which negative switching elements are in on state. The control circuit includes a command value signal generator generating command value signals Xu1, Xv1, and Xw1 from line voltage command value signals Xuv, Xvw, and Xwu, and includes a PWM signal generator generating PWM signals by the command value signals Xu1, Xv1, and Xw1. The command value signals Xu1, Xv1, and Xw1 are continuously at “0” for a predetermined period, and are continuously at “2” for another period. This enables reducing the difference between the period for which the PWM signals are low and the period for which they are high.

Abstract: An electric power conversion device includes a first arm and a second arm each including converter cells. The converter cell of the first arm is a first converter cell having a full-bridge configuration including an energy storing element and semiconductor switching elements. The converter cell of the second arm is a second converter cell having a half-bridge configuration including an energy storing element and semiconductor switching elements. Thus, short-circuit current between DC terminals is suppressed.