Abstract: A battery charger of a vehicle which has a simple structure and a small size, and more particularly, a battery charger of an electric vehicle charging a battery using power supplied by a variety of power sources is provided. The battery charger of an electric vehicle includes a switch network which includes a first switch configured to connect any one of an AC power input line and a neutral line, which form an AC power input terminal, to a power factor corrector, one or more second switches configured to selectively connect the AC power input terminal to the power factor corrector, a link capacitor, or an inverter, and a third switch configured to electrically connect a motor to a high voltage battery, and a controller configured to control the power factor corrector and the switch network according to conditions of input AC power input through the AC power input terminal.

Abstract: A power converter converts a medium-voltage output from a solar module to an appropriate voltage to power a solar tracker system. The power converter includes a voltage divider having at least two legs, a first semiconductor switch subassembly coupled in parallel with a first leg of the voltage divider, and a second semiconductor switch subassembly coupled in parallel with a second leg of the voltage divider. In implementations, the signals for driving the semiconductor switches of the first and second semiconductor switch subassemblies may be shifted out of phase from each other. In implementations, if the bus voltages to the semiconductor switches are not balanced, the pulse width of the driving signal of the semiconductor switch supplied with the higher bus voltage is decreased for at least one cycle.

Abstract: A power supply system comprises a primary regulation system, a secondary regulation system, and a controller. The primary regulation system comprises a primary transformer and a primary tap switch array. The secondary regulation system comprising a secondary transformer and an adjustment power signal generator. The controller is configured to control the adjustment power signal generator to apply an adjustment power signal to the secondary transformer. The secondary transformer is configured to combine the adjustment power signal with a base power supply signal from the primary transformer.

Abstract: The present disclosure relates to frequency control of power conversion modules for decreasing THD (Total Harmonic Distortion) in a power conversion device in which a plurality of power conversion modules operate in parallel. In one aspect of the present disclosure, an embodiment provides a power conversion device comprising a plurality of power conversion modules being connected in parallel to receive input power and provide output AC power, and a frequency controller controlling each operating frequency of the plurality of power conversion modules, wherein, the frequency controller may include a function as a first frequency regulating step for regulating each operating frequency of the plurality of power conversion modules, so that the operating frequencies of the plurality of power conversion modules have a specific relationship with each other.

Abstract: A chopper section of a power supply device includes a plurality of step-down chopper circuits, and multiphase control of the step-down chopper circuits is performed using gate signals having phases displaced from each other. This shortens the period with which output signals of the step-down chopper circuits are changed. Shortening the period reduces the amount of jitter resulting from a gap between the occurrence of a command signal and a sampling point that is a point in time at which a gate signal is generated. The number of phases of the gate signals equals the number of phases of the step-down chopper circuits. The control of the gate signal generator is asynchronous to feedback control by the controller. Points in time (sampling points) at which gate signals are generated are points in time of generation (sampling points) after a point in time at which the controller calculates a manipulated value.

Abstract: According to one aspect, an uninterruptable power supply (UPS) is provided. The UPS includes a first input constructed to receive input power from a first power source, a second input constructed to receive input power from a second power source, an output constructed to provide output alternating current (AC) power derived from at least one of the first power source and the second power source, a bypass switch having an on state and an off state coupled between the first input and the output, an inverter coupled between the second input and the output and constructed to generate the output AC power. The UPS being constructed to quickly transition from a first power delivery mode that provides output power derived from the first power source to a second power delivery mode that provides output power derived from the second power source.

Abstract: A power converter includes a chassis having attached thereto a holding fixture for mounting the chassis to a mounting portion in a suspended manner. The holding fixture includes a first member attached to a first surface of the chassis which faces the mounting portion, and a second member attached to the first member and a second surface of the chassis that adjoins the first surface.

Abstract: An active rectifier with a controller including a feedforward component, a modulator and a modulation index controller. The modulator generates switching control signals according to a reference to convert AC input power from the AC input to control the DC bus voltage at the DC output. The feedforward component computes the reference according to an estimated total inductance of the AC input, a grid voltage of the AC input, a modulation index reference, and a reactive power offset signal, and the modulation index controller computes the reactive power offset signal according to an error between the modulation index reference and a feedback modulation index.

Abstract: A voltage divider is described. The voltage divider comprises a pair of input nodes for receiving an input signal; a pair of output nodes configured to generate an output signal; a first capacitor having a first terminal coupled to a first output node of the pair of output nodes and a second terminal coupled to a second output node of the pair of output nodes; and a second capacitor having first terminal and a second terminal; a bypass switch having a first terminal coupled to the first terminal of the second capacitor and a second terminal coupled to the second terminal of the second capacitor; and a charge sharing switch coupled to the second terminal of the second capacitor; wherein the bypass switch and the charge sharing switch enable the sharing of charge between the first capacitor and the second capacitor.

Abstract: An electric power conversion device includes: a converter circuit which includes a boost chopper; a capacitor which is connected between output terminals of the converter circuit; a boost chopper which boosts a terminal voltage of the capacitor; a multiphase inverter circuit; and a boost chopper controller. In a case where the operation of the boost chopper is continuously stopped, the capacitor has a capacitance allowing the terminal voltage of the capacitor to have a pulse frequency twice as high as that of the AC power source. The multiphase inverter circuit has an output power which is allowed to fluctuate in synchronization with a power source.

Abstract: A relay includes a first contact for receiving an input signal, a second contact for receiving a power signal, a rectifier coupled to the first and second contacts for converting the power signal into a direct-current power signal when the power signal is an alternating-current power signal, a voltage clamping circuit coupled to the rectifier for clamping a voltage of the input signal and the power signal, a Schmidt trigger coupled to the voltage clamping circuit for generating a trigger signal according to the input signal and the power signal, and a power outputting circuit coupled to the Schmidt trigger for generating an output voltage according to the trigger signal and a supply power.

Abstract: A bridgeless power factor correction circuit includes: a first leg composed of a series circuit with a first rectifier and a first switch; a second leg that is composed of a series circuit with a second rectifier and a second switch and is connected in parallel to the first leg; a smoothing capacitor connected in parallel to the first leg; a snubber circuit that is connected between a first connection point, which is located between the first rectifier and the first switch and is connected via a first inductor to one end of an AC power supply, and a second connection point, which is located between the second rectifier and the second switch and is connected via a second inductor to another end of the AC power supply; and a control circuit that executes on/off control of the first switch and the second switch.

Abstract: A device includes a control unit that includes an oscillator circuit. The control unit is configured to generate, based on the oscillator circuit, at least one switching signal. The device also includes a direct current (DC)-to-DC conversion circuit comprising at least one electronic switch that is operatively coupled to the control unit. The DC-to-DC conversion circuit is configured to convert, based on the at least one switching signal, a DC input voltage to a DC output voltage, and the control unit is further configured to input, to the oscillator circuit, a current signal that is generated based on a measured output current of the DC-to-DC conversion circuit.

Abstract: A chopper assembly including at least two chopper units, and a controlling unit configured to generate a control signal for controlling an activation of the corresponding chopper unit in cycle. The activations of the at least two chopper units are controlled by the controlling unit to be either initially offset by a phase shift or adjusted to have a phase shift after a predefined time duration, the phase shift indicating a time difference between rising edges or between falling edges of respective pulses of different signals. The chopper assembly according to the present disclosure effectively mitigates the negative impact to various components within the circuit. Moreover, by controlling the duty cycles of the control signals, loads of each of the resistors will be equal.

Abstract: In a power conversion control apparatus incorporated in a power conversion system for converting a direct current (DC) voltage output from a converter into an alternating current (AC) using an inverter. The power conversion control apparatus includes a converter drive circuit configured to drive the converter, an inverter drive circuit, and a control electronic control unit (ECU). The inverter drive circuit operates a plurality of switching elements forming the inverter at a variably set switching speed. The control ECU outputs to the converter drive circuit an input voltage change command for changing an input voltage command for an input voltage to be output from the converter and input to the inverter. The control ECU outputs to the inverter drive circuit a drive command for driving the plurality of switching elements and a switching speed change command for changing the switching speed for the plurality of switching elements.

Abstract: This invention is generally concerned with power supply circuits, and more particularly, with circuits to supply power to a mains supply, such as domestic grid mains, from a photovoltaic device. A photovoltaic power conditioning circuit for providing power from a photovoltaic device to an alternating current mains power supply line, the circuit comprising: a DC input to receive DC power from said photovoltaic device; an AC output configured for direct connection to said AC mains power supply line; a DC-to-AC converter coupled to said DC input and to said AC output to convert DC power from said photovoltaic device to AC power for output onto said power supply line; and an electronic controller directly coupled to said power supply line to measure a voltage of said power supply line and a current in said supply line and to control said DC-to-AC converter responsive to said measuring.

Abstract: A circuit arrangement for use in a power conversion stage and a method of controlling a power conversion stage includes at least two electronic devices connected in series, the at least two electronic devices including at least one active power electronic device operable in a plurality of operation states including an active linearly operated state; wherein the at least one active power electronic device is arranged to be controlled and to operate in the plurality of operation states in each of a plurality conversion cycles, such that a generation of electric harmonics in the power conversion stage is suppressed during an operation of the power conversion stage.

Abstract: A drive includes: an inverter power circuit that applies power to an electric motor of a compressor from a direct current (DC) voltage bus; and a power factor correction (PFC) circuit that outputs power to the DC voltage bus based on input alternating current (AC) power. The PFC circuit includes: (i) a switch; (ii) a driver that connects a control terminal of the switch to a first reference potential when a control signal is in a first state and that connects the control terminal of the switch to a second reference potential when the control signal is in a second state; and (iii) an inductor that charges and discharges based on switching of the switch. The drive also includes a control module that generates the control signal based on a measured current through the inductor and a predetermined current through the inductor.

Abstract: A Power Factor Correction (PFC) controller includes an error amplifier for amplifying a difference between Vout and intended Vout to provide a power demand (Pdem) output at a compensation pin. A burst mode controller includes soft-start circuitry coupled to receive Pdem and to a drive pin which provides pulses to a control node of a power switch of a DC-DC converter during burst periods. The pulses slow ramping of line current over a first 2 to 36 switching cycles at a beginning of bursts when energizing the inductor to reduce a line current slope as compared to without ramping up, and for slowing ramping down of line current over the last 2 to 36 switching cycles to reduce a line current slope when de-energizing the inductor as compared to a line current without ramping down. The PFC controller does not utilize zero-crossings of the line voltage for burst period synchronization.

Abstract: A multi-stage switching power supply includes a first DC-DC power converter, a second DC-DC power converter and a control circuit. The control circuit is coupled to the DC-DC power converters for providing a first control signal to the first DC-DC power converter and a second control signal to the second DC-DC power converter. The control circuit is configured to vary a duty cycle of the first control signal to regulate an output voltage of the power supply, maintain a frequency of the second control signal at a fixed frequency, and in response to the duty cycle of the first control signal reaching a duty cycle threshold or an input voltage of the first DC-DC power converter reaching a voltage threshold, vary a frequency of the second control signal to regulate the output voltage of the power supply. Other example power supplies, control circuits, etc. are also disclosed.

Abstract: A multi-drain power module can include: a plurality of gallium-nitride (GaN) transistor dies connected to each other in series; a plurality of drain terminals, each drain terminal being respectively connected to the drain of a GaN transistor die; a series-switch-driver (SSD) connected to the gate of each GaN transistor die; a gate terminal connected to the SSD; a source terminal connected to a first source of a first GaN transistor die of the plurality of GaN transistor dies; a package encapsulating the plurality of GaN transistor dies and the SSD, and exposing the plurality of drain terminals, the gate terminal, and the source terminal.

Abstract: The present improvement essentially integrates a DC link inductance within an interphase power transformer (IPT). The integration is achieved by creating auxiliary magnetic paths for leakage inductance inside the IPT core. The magnetic path can be created, for example, by incorporating extra portions of magnetic material commonly referred to hereinafter as shunts. The IPT flux shared between windings does not cross these shunts. Therefore, this magnetic path increases the self-inductance of the IPT but does not contribute to the mutual inductance between windings. This extra magnetic path allows for leakage inductance of a much higher quantity than that achievable with a conventional IPT.

Abstract: A device includes a first silicon-controlled rectifier (SCR), a second SCR connected in anti-parallel with the first SCR, and a commutation module. The commutation module is configured to apply a reverse bias voltage to the first SCR or the second SCR to turn off the first SCR or the second SCR. The device further includes a voltage clamp configured to dissipate energy when the first SCR or the second SCR are turned off. The voltage clamp is charged as one of the first SCR or the second SCR are powered on.

Abstract: A driver circuit, a method for operating an inductor coil and an active transmission system, wherein a capacitor is charged by means of a charging current to a reference voltage and the charged capacitor is discharged in an oscillating manner via the inductor coil. The inductor coil is short-circuited when the voltage on the capacitor or a current flowing in the inductor coil has passed through at least one complete oscillating period.

Abstract: A power converter including a transformer, a resonant circuit including the transformer and a resonant capacitor having a characteristic resonant frequency and period, and output circuitry connected to the transformer for delivering a rectified output voltage to a load. Primary switches drive the resonant circuit, a switch controller operates the primary switches in a series of converter operating cycles which include power transfer intervals of adjustable duration during which a resonant current at the characteristic resonant frequency flows through a winding of the transformer. The operating cycles may also include energy recycling intervals of variable duration for charging and discharging capacitances within the converter.

Abstract: Described herein are methods and circuits for improving the performance of an AC to DC power supply. The methods and circuits achieve high power factor (PF) at the AC side and at the same time, reduce or substantially eliminate ripple in the DC output power. The methods and circuits provide an isolated topology including primary side voltage and current sensing and primary side ripple cancellation control. The methods and circuits may be used in any application where high power factor and/or low output ripple are required. In particular, the methods and circuits may be used in DC lighting applications, such as in light emitting diode (LED) lighting, wherein suppression of low frequency ripple in the output power eliminates visible flickering.

Abstract: The present invention discloses a control method and a control apparatus for a Flyback circuit. The Flyback circuit includes a primary switch, a secondary rectifier unit, a transformer and an output capacitor. The secondary rectifier unit includes a first terminal and a second terminal, which are electrically connected to the transformer and the output capacitor, respectively. In the control method for a Flyback circuit, after the secondary rectifier unit is controlled to be turned on once or twice according to the input voltage and/or output power of the Flyback, the primary switch is turned on to achieve the zero-voltage-switching. According to the invention, the zero-voltage-switching (ZVS) of the primary switch can be achieved under the entire input voltage range and the entire load range without adding additional power devices.

Abstract: A grid-tied inverter for supplying current to a power supply system includes an output bridge arrangement that is actuated via a pulse width modulator, wherein switching times of the output bridge arrangement are determined by using a periodic auxiliary signal, wherein the frequency of the periodic auxiliary signal varies according to a prescribed periodic wobble signal. The inverter further includes a synchronization unit configured to provide phase synchronization of the auxiliary signal to the power supply system, wherein the synchronization unit is configured to adjust a prescribed phase offset of the periodic auxiliary signal in relation to a phase of the power supply system, and a further synchronization unit configured to provide phase synchronization of the periodic wobble signal to the power supply system.

Abstract: The extended commutation cell (ECC) is a four-port, four-switch cell that allows for bidirectional energy transport in two orthogonal directions throughout the cell. By cascading multiple cells, a multilevel converter can be constructed with a high number of levels. The voltage across each cell capacitor can be adjusted independently of the load, resulting in high flexibility in output levels. Improved fault tolerance is also provided.

Abstract: Methods and systems for smart transfer switch circuits and operation, and for operation of transfer and/or cutoff switches in combination with a power-packet-switching-architecture (PPSA) power converter. The transistors of the transfer and cutoff switches, and the transistors of the phase legs of the PPSA power converter if present, preferably all use double-base bipolar transistors which have low on-state series resistance as the switching elements.

Abstract: A control circuit is provided for a buck converter that includes at least an inductor coupled to an output of the buck converter. The control circuit includes a power switch configured for coupling to a line voltage and configured for charging the inductor, an input line voltage sampling circuit, and a constant-voltage (CV) and constant-current (CC) control module coupled to the power switch. During a charging period of the inductor, the CV and CC control module is configured to control the power switch to provide a constant output current by maintaining a constant peak inductor current, even when the input line voltage changes. During a discharging period of the inductor, the CV and CC control module is configured to monitor the sensed output voltage to control the power switch to provide a constant output voltage.

Abstract: A chopper device includes: a series circuit connecting at one end to a positive pole of a DC power source and having a breaker and a reactor; a series circuit connected between another end of the stated series circuit and a negative pole of the DC power source and having switches; a series circuit connected in parallel to the switch and having a diode and a capacitor; and a series circuit connected in parallel to the switch and having a diode and a capacitor. The chopper device outputs a DC voltage at three potentials from both ends and a midpoint of a series circuit having the capacitors by turning the switches ON/OFF. The chopper device further includes other switches connected in parallel to the switches. When a short-circuit fault is presumed to have occurred in the switch, the other switch is turned ON before interruption is performed by the breaker.

Abstract: Compact integrated battery packs for hybrid vehicles are fully integrated with an on-board cooling system and include both the battery cells for supplying a primary voltage, such as powering a belt-driven starter generator (BSG) unit for engine start/stop, as well as a direct current (DC) to DC converter for stepping down the primary voltage to a secondary voltage for powering low voltage components and/or recharging a lead-acid battery. The on-board DC to DC converter decreases packaging size and eliminates the need for an alternator, which further decreases packaging size. Primary and secondary voltage output ports can also be implemented for quick and easy connection to other components. Configurations include single-layer and dual-layer arrangements with integrated air or liquid cooling for placement in or beneath a trunk of a vehicle, behind or beneath seats in a cab of a pickup truck, and/or beneath a vehicle.

Abstract: Power is inverted using double-base-contact bidirectional bipolar transistors in a three-level-inverter topology. The transistors not only switch to synthesize a PWM approximation of the desired AC waveform, but also have transient phases of diode conduction before each full turn-on or turn-off.

Abstract: Systems, devices and methods are provided for multi-device interactions. For example, a transmitting device detects a media content control command input by a user for operation of a first application client, wherein the media content control command includes media content identification; the transmitting device encodes the media content control command into an audio identifier string; and the transmitting device transmits the audio identifier string through first sound waves. A receiving device is configured to detect the first sound waves using a second application client, extract the audio identifier string from the first sound waves, decode the audio identifier string to acquire the media content control command, and operate on first media content corresponding to the media content identification included in the media content control command.

Abstract: In one embodiment, a bidirectional battery charger integrated with renewable energy generation includes a primary side AC/DC rectifier coupled to the electrical grid and a first DC bus, a DC/AC inverter coupled to the first DC bus and a primary winding, a secondary side AC/DC rectifier coupled to a secondary winding and a battery, and a boost converter coupled to a renewable energy generator and the first DC bus. The boost converter includes an active switch controlled by a control algorithm that, when renewable power is available, operates the active switch at a duty cycle that allows power to flow from the renewable energy generator to the first DC bus and on to charge the battery (without passing though the primary side AC/DC rectifier) or on to supply the electrical grid (without passing through the DC/AC inverter and secondary side AC/DC rectifier), and, when not available, disables the active switch.

Abstract: A hybrid alternating current (AC)/direct current (DC) distribution system for multiple-floor buildings includes per-floor rectifiers for converting supply side AC to DC. Each rectifier is configured to supply a plurality of DC loads associated with one floor of a multiple-floor building. The system further includes per-floor DC busses, each of the DC busses being configured to distribute the DC to the DC loads its respective floor. The system further includes at least one AC bus for supplying AC power to AC loads in the building.

Abstract: A power conversion circuit includes a variable voltage converter (VVC) with a stabilizing means for stabilizing its output voltage. The stabilizing means can be in the form of a diode that clamps the VVC output voltage to the VVC input voltage so that the output voltage does not drop below the input voltage when a load imposes a sudden power demand. The stabilizing means also enables a bypass mode in which transient power can be provided from a power source to an inverter without current flow through the VVC inductor or switches. When embodied as a diode, the stabilizing means can increase the maximum power that can be transferred by the power conversion circuit, improve the power response of the circuit, minimize control instability, and reduce power losses.

Abstract: A direct current (DC)-DC converter that includes a first switching converter and a multi-stage filter is disclosed. The multi-stage filter includes at least a first inductance (L) capacitance (C) filter and a second LC filter coupled in series between the first switching converter and a DC-DC converter output. The first LC filter has a first LC time constant and the second LC filter has a second LC time constant, which is less than the first LC time constant. The first LC filter includes a first capacitive element having a first self-resonant frequency, which is about equal to a first notch frequency of the multi-stage filter.

Abstract: The present disclosure relates to a synchronous rectification circuit adapted to an electronic transformer. Operation states of four transistor switches in the synchronous rectification circuit are adjusted in accordance with a detected input voltage signal of the synchronous rectification circuit to achieve synchronous rectification. Moreover, the transistor switches in a rectifier bridge and a switching control circuit are all integrated into a single chip to have an increased integration level, a reduced chip size, and high efficiency. The present disclosure also relates to a switching power supply comprising the above synchronous rectification circuit.

Abstract: Novel techniques for balancing power or current drawn from multiple power supply inputs by controlling switching circuits associated with the respective power supply inputs. Each switching circuit may be controlled so as to limit current in its transformer or inductor in each switching cycle to a peak or average current value common to all switching circuits.

Abstract: A power converter can include an inverter including, connected in series, switching elements, the inverter circuit being connected to both ends of a DC power source series circuit resulting from connecting in series a DC power source and a DC power source. Also included can be an AC output terminal that is connected to a connection point of the switching element and the switching element, an AC output terminal that is connected to a connection point of the DC power source and the DC power source, a bidirectional switch element one end of which is connected to the AC output terminal and the other end of which is connected to a terminal of an AC power source and a bidirectional switch element one end of which is connected to the AC output terminal and the other end of which is connected to the AC power source.

Abstract: A power converter that can supply constant voltage to a load even upon fluctuation of voltage of an AC power source includes an inverter circuit resulting from connecting switching elements in series, the inverter circuit being connected to both ends of a DC power source series circuit resulting from connecting in series two DC power sources; an AC output terminal that is connected to a connection point of the switching elements; another AC output terminal that is connected to a connection point of the DC power sources; and a bidirectional switch element including one end connected to the AC output terminal U and another end connected to a terminal of an AC power source.

Abstract: In a method arrangement, providing a zero voltage transition circuit including an input node, an output node, a switch node, an output inductor coupling the switch node and output node, an output capacitor coupling the output node and ground, a first switch coupling the input node and switch node, a second switch coupling switch node and ground, a first auxiliary switch coupling the input node to an auxiliary node, a second auxiliary switch coupling the auxiliary node to ground, and an auxiliary inductor coupling the auxiliary node to the switch node; closing the first auxiliary switch to couple the input to the auxiliary node; subsequently, when a current is below a cutoff threshold, opening the second switch; after a first delay period, opening the first auxiliary switch and closing the second auxiliary switch; and after a second delay period, closing the first switch. Apparatus and additional method arrangements are disclosed.

Abstract: In at least one embodiment, the invention provides a bidirectional amplifier and method of control that enables immediate feedback directly from the output for fast response and low distortion. Mechanisms responsive to instantaneous feedback eliminate undershoot, overshoot, and sub-harmonic behavior. One embodiment comprises two switches and a single two-terminal inductor. Another embodiment produces a bipolar output from a single unregulated supply rail. The use of Predictive Energy Balancing controls yield high efficiency and low total harmonic distortion. These amplifiers are suited for audio application, and can drive piezo or dynamic speakers.

Abstract: In one embodiment, a method of driving a load can include: monitoring an AC input to a rectifier circuit in real-time, where the rectifier circuit can include first and second rectifier circuits, and controlling first and second controllable switches based on a state of the AC input is in a first state. For example, a first state can include the AC input being in a positive half cycle and increasing, or the AC input being in the positive half cycle and decreasing while being at least as high as a predetermined threshold value. The AC input can be used to supply power to a load circuit and an output capacitor via the first rectifier circuit when the AC input is in the first state, where the first rectifier circuit can include a first diode and the second controllable switch.

Abstract: Various embodiments of the invention reduce switching losses associated with existing non-zero volt switching and non-zero current switching in DC/DC converters without the need for a resonant design. Certain embodiments of the invention provide for improved efficiency by reducing switching losses related to the simultaneous presence of current and voltage across high power switching devices. In certain embodiments, this is accomplished by adding a relatively small inductor and two switching elements to various switching regulator topologies. Energy stored in the inductor is used to transition the output of the switching converter to achieve zero volt switching and zero current switching.

Abstract: A motor control apparatus includes: a PWM rectifier which converts an AC power to a DC power; an LCL filter provided between the AC power supply and the PWM rectifier; a cooling fan for cooling the LCL filter; a temperature detection unit for the LCL filter; an alarm detection unit for detecting an alarm state when a temperature detection value is a predetermined value or more; a time measurement unit for measuring elapsed time from a start of a normal operation of the PWM rectifier; and a protection unit which determines, in accordance with the elapsed time, an alarm generation cause whether the alarm state is generated due to a reverse connection of a power line of the LCL filter or due to a stop of the cooling fan when the alarm state is notified, and performs a protection operation in accordance with the alarm generation cause.

Abstract: A resonant current limiting device, for a resonant current passage having a loop shape including at least one capacitor and a wiring passage with at least one inductor or inductance component, includes: an electric storage element connected in series with the capacitor; a driving power source; and a voltage controller that charges and discharges an electric charge in the electric storage element, which is supplied from the driving power source, controls a terminal voltage of the electric storage element to be a predetermined instruction voltage, and restricts a resonant current component flowing through the wiring passage.

Abstract: A power converter circuit includes a power converter with a plurality of series connected converter cells. Each of the plurality of converter cells includes at least one first half-bridge circuit including a first silicon MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) and a second silicon MOSFET. At least one of the plurality of converter cells is configured to operate in a continuous current mode.