Abstract: A rectifying element includes a MOS transistor series-connected with a Schottky diode. A bias voltage is applied between the control terminal of the MOS transistor and the terminal of the Schottky diode opposite to the transistor. A pair of the rectifying elements are substituted for diodes of a rectifying bridge circuit. Alternatively, the control terminal bias is supplied from a cross-coupling against the Schottky diodes. In another implementation, the Schottky diodes are omitted and the bias voltage applied to control terminals of the MOS transistors is switched in response to cross-coupled divided source-drain voltages of the MOS transistors. The circuits form components of a power converter.

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 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 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 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.

Abstract: Each phase arm of a power conversion device includes at least one converter cell connected in series. For each converter cell, an element driving unit is provided which turns on one switching element in the converter cell as a startup element. The element driving unit is supplied with power from a DC capacitor, and when voltage of the DC capacitor exceeds startup voltage Vsh, turns on the startup element. Thus, at the time of startup of the power conversion device, the DC capacitor in each converter cell is initially charged to desired voltage.

Abstract: An inverter, a method and a device for controlling the inverter are provided, to improve efficiency of the inverter. The inverter includes a three-level active clamped topology including a first and second bus capacitors and an inverter circuit, the inverter circuit includes a first switch transistor to a sixth switch transistor. The inverter further includes a seventh switch transistor and an eighth switch transistor; the seventh switch transistor and the eighth switch transistor are connected in series between the positive direct current bus and the negative direct current bus in a same direction, and a serial point of the seventh switch transistor and the eighth switch transistor is connected to a serial point of the second switch transistor and the third switch transistor; and the seventh switch transistor and the eighth switch transistor are anti-parallel connected to corresponding diodes respectively.

Abstract: An energy storage system (ESS) for an electrical system includes an energy storage, and a converter interface arranged for connecting the energy storage to the electrical system. The converter interface includes a modular multilevel converter in which each phase leg includes a plurality of series connected cells of which at least one is a half-bridge cell and at least one is a full-bridge cell.

Abstract: Systems and methods for providing peak current mode control (PCMC) for power converters using discrete analog components. Peak current mode control functionality for latching, set, reset, clocking and slope compensation is provided via available analog components that provide improved performance, design flexibility, reliability, and radiation tolerance. Discrete analog components may include analog comparators, resistors, capacitors, diodes, etc.

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 high1.

Abstract: Hybrid modulation strategies are provided for single phase and three phase inverter topologies. According to hybrid modulation strategy embodiments, one line frequency period is divided into two operation modes based on the polarities of output voltage and output current. When polarities of the output voltage and output current are the same, a nominal voltage level modulation is used to generate the output voltage. When polarities of the output voltage and output current are opposite, a lower voltage level modulation is used to generate the output voltage. In one embodiment, a nominal voltage level modulation is five voltage level modulation, and a lower voltage level modulation is three or two voltage level modulation. Embodiments allow inverters to be constructed with fewer switches, and improve performance of multilevel inverters. The hybrid modulation strategies may be implemented in multilevel inverters such as active neutral point clamped (ANPC) and neutral point clamped (NPC) inverters.

Abstract: Five-level topology units and inverters based on the five-level inverter units without a boost circuit. Cost is reduced by using only one AC filtering inductor and high efficiency is achieved in the absence of an extra boosting circuit. Leakage current is eliminated substantially by using a half-bridge inverter module. A five-level inverter including a five-level topology unit without a boost circuit to raise the input voltage is able to output the same AC power as a five-level full bridge inverter under the same working condition.

Abstract: A converter includes a first bridge arm, a second bridge arm, two switch units and a voltage clamp circuit. The first bridge arm includes a first switch unit and a second switch unit that are electrically coupled in series at an output terminal. The second bridge arm includes two voltage sources that are electrically coupled in series at a neutral point terminal. The two switch units are electrically coupled in series at a common connection terminal, and are arranged between the neutral point terminal and the output terminal. The voltage clamp circuit is electrically coupled to the output terminal, the common connection terminal, the neutral point terminal, and one of a positive input terminal or a negative input terminal, and the circuit is shared by the two switch units to clamp voltages across the two switch units.