Abstract: The present invention relates to a near zero current-ripple inversion circuit including top and bottom cells, a transformer (T1) comprising primary windings (P1, P2) and a secondary winding (S1), and at least one middle cell connected in series between the top and bottom cells. The top cell comprises two capacitors (C1, C2) and a switch (Q1) each connecting to the middle cell, and an inductor (Lr1) and the primary winding (P1) connected in series between the capacitor (C1) and switch (Q1), wherein the switch (Q1) is connected to the capacitors (C1, C2) respectively. The bottom cell comprises a capacitor (C3) and a switch (Q2) each connecting to the middle cell, and an inductor (Lr2) and the primary winding (P2) connected in series between the capacitor (C3) and switch (Q2), wherein the primary winding (P2) is connected to the middle cell, and the capacitor (C3) and switch (Q2) are connected.

Abstract: The invention relates to a method for controlling a multi-phase power converter having at least two phase modules (100) comprising valve branches (T1, . . . , T6) having bipolar subsystems (10, 11) connected in series, at low output frequencies (f). According to the invention, a target value (u1 (t), . . . , u6 (t)) of a valve branch voltage overlaps a common-mode voltage (uCM(t)) such that a sum of two valve branch voltages (u1 (t), U2 (t) or U3 (t), U4 (t) or U5 (t), U6 (t)) of each phase module (100) equals an intermediate circuit voltage (Ud) of said multi-phase power converter. In this manner a known converter having a triphase power converter comprising distributed energy accumulators on the grid and load side, or merely on the load side, may be utilized as a drive converter, which may start up from the idle state.

Abstract: The present invention generally relates to power electronic switching circuits and in particular to inverter modules employing two or more controlled switches that can be used with reactive loads. An inverter circuit is provided which includes first and second input terminals for being connected to a DC power source; first and second output terminals for outputting an AC voltage; at least one metal oxide semiconductor field effect transistor, MOSFET, having a parasitic body diode. The inverter circuit further includes at least one disabling element for disabling said body diode. This may result in an improved efficiency of the inverter circuit in combination with a reactive power capability. Further, a semiconductor switching device is disclosed, comprising at least one metal oxide semiconductor field effect transistor, MOSFET, and at least one insulated gate bipolar transistor, IGBT, wherein said MOSFET and said IGBT are connected in parallel.

Abstract: A pulse width modulation controller and method for output ripple reduction of a jittering frequency switching power supply detect the current of a power switch of the switching power supply to generate a current sense signal, and adjust the gain or the level of the current sense signal according to the switching frequency of the power switch to adjust the on time of the power switch, to reduce the output ripple of the switching power supply caused by the jittering frequency of the switching power supply.

Abstract: According to one embodiment, a system includes modules to detect a node voltage and an output current of a converter, a detector to obtain an effective power value, a system condition detector to detect a power supply condition in the electric system or the operating conditions of devices included in the electric system and then output a first signal, a setting unit to switch a set value to a preset first or second value and then output the set value, a unit to calculate an angular frequency of an output voltage of the converter on the basis of an output of the detector, the value, and an output of the system condition detector, and a unit to calculate a target value of the converter.

Abstract: To make it possible to avoid an unstable state with a simple configuration even one of the phases of the motor fails. A motor drive system in accordance with the present invention includes a motor to which a plurality of phase coils of five phases or more are connected in a star connection, an inverter connected to one end of each of the phase coils, the inverter being configured to convert a DC power into an AC power and supply the AC power to each phase of the motor, a power relay disposed at another end of each of the phase coils, the power relay being configured so as to be able to cut off a supply power to at least one phase coil among the plurality of phase coils of the motor by using a plurality of contact points interposed between the star-connected coils, and a control unit that generates a control signal for the inverter and thereby controls driving of the motor.

Abstract: A three-phase power converter includes a converter configured to convert a three phase AC power input to a DC power output, the DC power output being provided to high and low sides of a DC bus, and an inverter coupled to the DC bus and configured to convert the DC power to a three phase AC output. The inverter comprises three legs and each leg comprises a pair of solid state switches and a respective output therebetween. The power converter further includes a common mode voltage control filter comprising three filter inputs and two filter outputs, each filter input coupled to an output of a respective leg of the inverter and each filter output coupled to a respective side of the DC bus.

Abstract: A method is provided for determining a control scheme for a voltage source converter (VSC) with a topology of three bridge legs between each of three phases of a grid and a neutral point. The method includes: analyzing the waveform of the grid and/or a load voltage and determining an allowed period for no-swilching of the corresponding bridge leg; operating the VSC with different clamping carrier modulator frequencies, and then analyzing the balance in the operating junction temperatures and/or power losses across the active switches and also analyzing the total losses of the VSC; comparing the balance and the total losses of different clamping carrier modulator frequencies and selecting the clamping carrier modulator frequency; operating the VSC with the selected clamping carrier modulator frequency, and optimizing the balance in the operating junction temperatures and/or power losses across the active switches and the total losses of the VSC.

Abstract: A device for converting a DC voltage into an AC voltage includes a passive electronic filter having a first and second energy storage element, a third energy storage element placed between the first and second energy storage elements, a fourth energy storage element connected between a junction of the first energy storage element and the third energy storage element and an AC terminal and a fifth energy storage element connected between a junction of the second energy storage element and the third energy storage element and the AC terminal. The energy storage elements are of two different types, capacitive and inductive, with values selected to provide reduction of frequency components at two times the fundamental frequency of the AC voltage and at three times the fundamental frequency of the AC voltage.

Abstract: A method of controlling the grid-side current of a single-phase grid-connected converter having an LCL filter connected between the output of the converter and the grid includes measuring a grid voltage and at least one signal in a group of signals consisting of a grid-side current, a converter-side current and a capacitor voltage, estimating the fundamental component of the grid voltage, forming a grid-side current reference, a converter-side current reference and a capacitor voltage reference for the grid-side current of the LCL filter, forming estimates for the non-measured signals in the group of signals, forming a grid-side current difference term, a converter-side current difference term and a capacitor voltage difference term, and controlling the output voltage of the converter based on the grid voltage, a formed injection term and a formed estimate of the harmonic distortion term to produce a grid side current corresponding to the current reference.

Abstract: A device for converting a DC voltage into an AC voltage and vice versa comprises at least one phase leg with a first voltage source and a first inductor connected in series between a first DC terminal and a first AC terminal and with a second inductor and a second voltage source connected in series between the first AC terminal and a second DC terminal, where each of the voltage sources comprises at least a first and a second submodule in series-connection, each submodule comprising at least one power electronic switch connected in parallel with at least one capacitor. In the device, a passive electronic filter is arranged between the first and the second inductor as well as the first AC terminal for reducing harmonics in a circulating current.

Abstract: An arrangement transmits power between a DC power line and an AC power line carrying a voltage having a number of phases. The arrangement includes a number of transformers, one for each phase and a number of power transfer modules, one for each phase, connected in series between the DC power line and ground, where each module includes a first branch including series connected converter cells and a second branch including series connected switching elements. The primary winding of a transformer is connected to a corresponding AC phase conductor of the AC power line and the secondary winding is connected between a midpoint of the first branch and a midpoint of the second branch of a corresponding power transfer module.

Abstract: An alternating current chopper circuit with low noise is disclosed. The circuit includes a switching circuit, a first freewheel circuit, and a second freewheel circuit. The switching circuit has a control switching unit, which turns on and or off accordingly to a control signal. The first freewheel circuit and the second freewheel circuit are for providing a current-conducting path to the motor, when the control switching unit is turned off.

Abstract: A voltage source converter station including a multilevel voltage source converter, for conversion of electrical power between AC and DC, and a control system. The voltage source converter includes a plurality of switching cells including switchable semiconductors, and the control system includes at least one main control unit for providing a voltage reference signal and a plurality of cell control units. Each cell control unit uses carrier based pulse width modulation for controlling the switching of a respective cell, where the main control unit is communicatively connected to the cell control units and provides the reference voltage signal to each cell control unit and each cell control unit creates a switching signal to each respective switching cell using the reference voltage signal and a carrier signal to effectuate the conversion.

Abstract: A power conditioner of a photovoltaic system is configured operate at higher accuracy. A chopper circuit, a capacitor connected in parallel to the chopper circuit, and a control circuit that controls an ON/OFF status of switch elements in the chopper circuit to control charging and discharging of the capacitor are provided. The control circuit includes a measurement control section that measures an inter-end voltage of the capacitor and a control circuit section that performs a predetermined control operation from a measurement output of the measurement circuit section. The measurement circuit section includes a differential amplifier circuit that differentially amplifies the inter-end voltage of the capacitor. The circuit control section calibrates an in-phase component in the output of the differential amplifier circuit as an in-phase error and performs the control from the calibrated output from the differential amplifier circuit.

Abstract: When applying a high frequency voltage which alternates on positive and negative sides to a permanent magnet synchronous motor, a driving system of synchronous motor switches the applied voltage phase by 120 degrees successively and applies resultant voltages to three phases. A pulsating current generated by applying a high frequency voltage is detected at timing of elapse of a predetermined time ?t since an output voltage of at least one phase has changed from a state in which all output voltages of the three phases of a power converter are positive or negative. Current detection is conducted by using a DC resistor or a phase current sensor provided on a DC bus. A magnetic pole estimation unit calculates the rotor magnetic pole position of the permanent magnet synchronous motor on the basis of differences between positive side and negative side change quantities in three-phase currents obtained from detected current values.

Abstract: A power converter system includes a converter configured to be coupled to a power generation unit for receiving power from the power generation unit, and a bus coupled to the converter, wherein a voltage is generated across the bus when electricity is conducted through the power converter system. The power converter system also includes an inverter coupled to the bus and configured to supply power to an electrical distribution network, and a control system coupled to the converter and to the inverter. The control system is configured to gradually adjust the voltage across the bus during at least one of a shutdown sequence and a startup sequence of the power converter system.

Abstract: A capacitor circuit includes a first capacitor line including a film capacitor and a second capacitor line including a ceramic capacitor that are connected in parallel with each other. The second capacitor line includes an inductance element that is connected in series with the ceramic capacitor. The inductance element is set to a value such that a series resonant frequency of the first capacitor line and a series resonant frequency of the second capacitor line are matched.

Abstract: An inverter and an active power filter system have been disclosed in the invention, so that the application range of the inverter under the occasions of different capacitor requirement can be widened, the cost can be decreased, and the efficiency can be improved. The technical scheme is: an auxiliary capacitor module can be added on the traditional inverter structure and connected in parallel selectively with the capacitor in the inverter. In a system without connecting an external auxiliary capacitor module, the value of capacitance can be designed to be smaller to satisfy the application under normal occasions. If the device operates under the occasions having large harmonic current or having large neutral line current, the ripple current on the capacitor will be larger so that large capacitance will be required to satisfy the life requirement, therefore, the problem can be solved by a method of installing an auxiliary capacitor module.

Abstract: A multiple inverter with neutral line inductor and an active power filter system are disclosed. In the disclosure, the multiple inverter comprises at least two inverter units connected in parallel, the midpoint of the direct current bus in each inverter unit is connected to the neutral line N through the respective neutral line inductor. The multiple inverter can suppress the ripple produced by the neutral line current without increasing the direct current bus capacitor.

Abstract: A method and an apparatus for controlling a grid-connected converter which includes a boost converter, a buck converter, and a current source inverter having an output CL filter. An input of the buck converter input is connected to an output of the boost converter, and an input of the current source inverter is connected to an output of the buck converter. The method includes controlling a boost converter input voltage, controlling a boost converter output voltage through control of a buck converter output voltage, and controlling the current source inverter to produce an AC current from the buck converter output voltage. The apparatus implements the method.

Abstract: A multiple inverter and an active power filter system are disclosed in the invention, said multiple inverter can decrease the volume and harmonics, increase the efficiency and decrease the cost, and can be applied to various occasions. The technical scheme is: the filter assembly in the multiple inverter is installed at the output inductor of the multiple inverter for filtering the harmonics.

Abstract: The present invention includes: an inverter 1 configured to perform pulse wide modulation on an output from a DC power source 5; a first capacitor pair 41 provided at an input side of the inverter and including two capacitors serially connected to form a neutral point; a second capacitor pair 42 provided at an output side of the inverter and including two capacitors serially connected to form a neutral point; a bypass path g for a leakage current formed by connecting the neutral point of the first capacitor pair and the neutral point of the second capacitor pair to each other; at least one common mode choke coil 3 provided between the first capacitor pair and the second capacitor pair and configured to suppress a common mode current generated in the inverter; and an output filter 2 configured to convert a voltage, which is outputted from the inverter and subjected to the pulse wide modulation, into a voltage in a sine wave form.

Abstract: A method of damping harmonic output of an inverter is provided. The method may receive output phase signals from sensors disposed at an output of the inverter and on an associated electrical grid, filter the output phase signals using a low pass filter configured to extract a fundamental component from the output phase signals, isolate harmonics from the output phase signals based on the extracted fundamental component, and subtract the harmonics from the output phase signals.

Abstract: An electric power converter includes a DC stabilization circuit (2) configured to stabilize a DC voltage from DC power supply (1), and an inverter (3) configured to convert the DC voltage stabilized by the DC stabilization circuit (2) to an AC voltage. The DC stabilization circuit (2) includes an aluminum electrolytic capacitor (4) configured to smooth the DC voltage, a saturable reactor (5) configured to prevent the DC stabilization circuit (2) from oscillating, and a film capacitor (6) configured to supply a ripple current to the inverter (3).

Abstract: Disclosed is a system and a method for controlling torque of induction motor in electric vehicle. The system and method for controlling torque of induction motor in electric vehicle according to the present disclosure has an advantageous effect in that torque control problems caused by saturation of magnetic flux, parameters of induction motor and changes in battery voltages during control of torque in the induction motor can be solved using a look-up table (a type of data table), thereby enhancing accuracy in torque control and improving travel performance and fuel efficiency of the electric vehicle.

Abstract: A power conversion apparatus includes two power conversion circuits, two direct-current inductors, and a pulse-width-modulation control circuit. One of the two power conversion circuits is connected in parallel to a direct-current load or a single-phase alternating-current load, and the other of the two power conversion circuits is connected in parallel to a three-phase alternating-current load. The two power conversion circuits are connected in reverse polarity to each other via the two direct-current inductors. The pulse-width-modulation control circuit pulse-width-modulates the two power conversion circuits, allows switching between the two power conversion circuits, and realizes a bidirectional step-up/down operation between the direct-current load or single-phase alternating-current load and the three-phase alternating-current load.

Abstract: The present invention is a single-phase voltage source DC-AC power converter and a three-phase voltage source DC-AC power converter.

Abstract: A power converting apparatus and a photovoltaic module are discussed. The power converting apparatus includes a converter including a tapped inductor and a first switch, the converter converting a level of an input direct current (DC) voltage and outputting the level-converted DC voltage, and an inverter including a plurality of switches, the inverter converting the level-converted DC voltage into an alternating current (AC) voltage. The inverter operates separately in a first switching mode where the inverter performs a switching operation at a first frequency for a first period of the converted AC voltage and a second switching mode where the inverter performs a switching operation at a second frequency for a second period of the converted AC voltage, the second frequency being lower than the first frequency.

Abstract: A power conversion device in which an inverter for controlling a load is connected to an alternating current power system, and arranged to perform an electric power assist by connecting a direct-current power assist device having a chopper and a charge device to a direct-current circuit of the inverter. The device including a setting section to set charge and discharge target values in accordance with a sensed value of the direct-current voltage of the inverter; a charge control section to perform a charge control based on the charge target value; a discharge control section to perform a discharge control based on the discharge target value; and an instantaneous-low high-speed-compensation section to estimate an electric power corresponding to a direct-current sensed voltage of the inverter, and to output a value to the discharge control section which is obtained by dividing the estimated value by the direct-current sensed voltage.

Abstract: A power supply controller is provided for providing a drive current to a control terminal of a power transistor in three time intervals. The controller includes control circuits configured to control the drive current in multiple stages. During a first time interval, first drive current includes a current spike for turning on the power transistor in response to a start of the control signal pulse. During a second time interval, a second drive current includes a ramping current substantially proportional to a magnitude of a current through the power transistor. During a third time interval, current flow to the power transistor is at least partially turned off before an end of the control signal pulse.

Abstract: In a system comprising a fuel and a rotating electrical machine, damage of a switching element is prevented when the rotating electrical machine becomes a locked state. In a power controller, it is monitored whether the rotating electrical machine is in the locked state or not. When the rotating electrical machines is judged to be in the locked state, a command for dropping output voltage is given to the fuel cell. Thus, inverter input voltage can be dropped, loss power of the switching element in the rotating electrical machine is dropped and damage can be suppressed. The rotating electrical machine is monitored to cancel the locked state or not while dropping of inverter input voltage is controlled. When the locked state is judged to be canceled, control of the fuel cell is returned to a state of regular operation control.

Abstract: According to one embodiment, a grid-tie inverter includes: a inverter performing pulse width modulation for a DC voltage; a first capacitor circuit connected to an input side of the inverter so as to form a neutral point; a second capacitor circuit connected to an output side of the inverter so as to form a neutral point; a common mode current bypass channel formed by connecting the neutral points of the first capacitor circuit and the second capacitor circuit; a grounded capacitor provided between the bypass channel and a ground; a first common mode choke coil unit including a common mode choke coil at least one of between the first capacitor circuit and the inverter and between the inverter and the second capacitor circuit; and an output filter converting a pulse width-modulated voltage outputted from the inverter into a sine AC voltage.

Abstract: A power conversion device includes a power switching circuit that has a plurality of series circuits in each of which a switching element that operates as an upper arm and a switching element that operates as a lower arm are connected in series, and a control circuit that generates control signals for controlling the continuity or discontinuity of the switching elements, and, if the relationship between the state of a switching element in a control cycle and the state of the switching element in the next control cycle is a discontinuous relationship, that additionally performs control to make the switching element continuous or discontinuous on the basis of the state of the switching element in the control cycle and the state of the switching element in the next control cycle.

Abstract: In a neutral-point-clamped power inverter, gate drive circuit comprises four drive blocks providing bipolar DC signals to control switch gates. The first and third drive blocks are bootstrapped to the second and fourth. Inverter's neutral bus is commonly connected to the positive and negative DC buses through clamping capacitors. An arm of four serially-stacked-switches bridges DC buses. The switch arm midpoint is an output of the inverter. A first clamping diode connects the neutral bus to the first switch emitter; a second clamping diode connects the neutral bus to the third switch emitter. In one embodiment, a second switch arm mirrors the first, providing a second output; a second gate drive circuit mirrors the first. A bias circuit provides two reference voltages for the gate drive circuits. Three isolated DC sources provide signals that, when used by the gate drive circuit, result in seven isolated bipolar DC signals.

Abstract: A power conversion system for providing power to an electrical grid is described. The power conversion system includes a power converter coupled to a power source and the electrical grid. The power conversion system also includes a converter controller coupled to the power converter and configured to control operation of the power converter to actively cancel harmonic current received at the power converter from the electrical grid.

Abstract: Provided are methods, circuits, and systems for obtaining power from a power generator such as a photovoltaic cell or a fuel cell. The methods, circuits, and systems comprise converting substantially DC output power from the power generator into a high frequency AC voltage while rejecting or minimizing oscillations in the output power from the power generator; converting the high frequency AC voltage into a high frequency substantially sinusoidal voltage or current; and converting the high frequency substantially sinusoidal AC voltage or current into (i) a DC voltage or current, and (ii) a low frequency substantially sinusoidal AC voltage or current; wherein the high frequency substantially sinusoidal AC voltage or current is isolated from the DC voltage or current or the low frequency substantially sinusoidal AC voltage or current.

Abstract: Systems and methods are provided for delivering energy from an input interface to an output interface. An electrical system includes an input interface, an output interface, an energy conversion module coupled between the input interface and the output interface, and a control module. The control module determines a duty cycle control value for operating the energy conversion module to produce a desired voltage at the output interface. The control module determines an input power error at the input interface and adjusts the duty cycle control value in a manner that is influenced by the input power error, resulting in a compensated duty cycle control value. The control module operates switching elements of the energy conversion module to deliver energy to the output interface with a duty cycle that is influenced by the compensated duty cycle control value.

Abstract: The present invention provides an electric circuit wherein a multi-phase bridge is connected in series with a plurality of single-phase bridges. The multi-phase bridge is composed of a plurality of 3-level diode clamped legs, while the single-phase bridges each is composed of two 3-level diode clamped legs. The present invention also provides control strategy for synthesizing multi-level voltage waveforms from output voltages of the multi-phase bridge and the plurality of single-phase bridges.

Abstract: A system and method of use of a three-phase inverter driver is disclosed. In some exemplary embodiments three single-phase inverters are connected to the three-phase AC input of electric vehicle supply equipment (EVSE) so that each of the single-phase inverters provide one of the three phases of the AC signal used by the EVSE. The single-phase inverters are rectified and either have variance in their output frequencies or have their phases staggered so that the maximum voltage provided to the EVSE remains at a consistently high level. In some cases, the three phases each cross polarity simultaneously, resulting in a drop in the maximum three-phase voltage, so low-capacity capacitors are used in conjunction with the inverters to bridge these gaps in voltage. Embodiments use readily available, inexpensive components that have regulatory safety-approval and therefore may allow implementation on a vehicle or with a load leveling energy storage system.

Abstract: A current control unit takes a deviation between a current command value and a current flowing through an inverter of a power conversion device, and controls the inverter based on the deviation. A harmonic sensing part receives input of an output current of an AC filter, and outputs a predetermined order harmonic of the input current in a direct current value form. A disturbance observer estimates the disturbance of the harmonic based on the output current and a coefficient defined as an inverse function of a transfer function from harmonic suppression current command value to filter output current detection value. A harmonic suppression control unit takes the deviation between the estimated harmonic disturbance and a disturbance command value that suppresses the disturbance, and calculates a harmonic suppression current command value. The harmonic suppression current command value is superimposed on the current command value of the current control unit.

Abstract: A controller of a power converter has: an average loss calculator (202) calculating an average loss in a semiconductor device; and a partial temperature variation estimation part (204), while regarding the semiconductor device as a thermal network including at least one combination of a thermal resistance and a thermal time constant, estimating a partial temperature variation of the combination from a loss in the semiconductor device and the combination of the thermal resistance and the thermal time constant. The partial temperature variation estimation part (204) estimates an average temperature from the loss, the thermal resistance, and the thermal time constant; extracts a pulsation envelope temperature exceeding the maximum value of a pulsation temperature dependent on the average loss and the pulsation frequency; and estimates a temperature variation in the semiconductor device by adding the average temperature and the pulsation envelope temperature.

Abstract: A method of controlling a pulse width modulated (PWM) voltage regulator including a control circuit of a power stage, and a circuit configured to determine a duration of charge phases and further configured to receive a charge signal and to generate a logic command may include controlling, using the control circuit, switches of the power stage as a function of the logic command at an end of a charge phase and at a start of a discharge phase of an output capacitance. The method may also include generating the charge signal to be one of enabled and disabled during charge phases and another of enabled and disabled during discharge phases, and delaying, at each PWM cycle, the logic command with respect to a previous PWM cycle to compensate at least one of a phase and a frequency difference between each PWM cycle and a reference clock signal.

Abstract: A harmonic cancelling interphase magnetic device (1) comprising a magnetic core of rectangular shape with three wound legs (14) and two non-wound legs (12), wherein the cross-section of said non-wound legs (12) is thinner than the cross-section of said wound legs (14). The magnetic device is designed for a front end multi-pulse rectifier or inverter. Its use enables reduction of the harmonics of the currents absorbed or injected to three-phase power line. Compare to known solutions, cost, material and dimensions of the magnetic device are significantly reduced.

Abstract: Disclosed herein is a torque control method for a high-speed Switched Reluctance Motor (SRM), which controls a torque in the high-speed operation of a 2-phase SRM. In the torque control method for a high-speed SRM, a positive torque (T*mA) of an active phase (A phase) of the two phases of the SRM is compensated for based on a negative torque attributable to an inactive phase (B phase) of two phases during a compensation control enable interval (ENA) ranging from a time point at which the active phase (A phase) is turned on to a time point at which tail current of the inactive phase (B phase) remains. Accordingly, the present invention can remarkably reduce a torque ripple occurring in high-speed operation mode in consideration of the influence of a negative torque attributable to tail current.

Abstract: A power conversion apparatus has a rectification circuit provided for converting AC power supplied from an AC power supply into DC power. The rectification circuit has a configuration in which series circuit whose number corresponds to the number of phases of an input AC are connected in parallel between a positive-side line and a negative-side line. The AC power supply is connected to AC input points, each corresponding to a connection point between a rectifying device and a semiconductor switching device in each of the series circuits, and connected to a point having ground potential through noise suppressing series circuits respectively. In each of the noise suppressing series circuits, a switch unit and a capacitor are connected in series. In this manner, it is possible to provide a power conversion apparatus which can reduce a noise terminal voltage while solving problems in volume and cost simultaneously.

Abstract: The present invention discloses a controllable rectification comprising an inverter (10), a control panel (20) and a drive panel (30). The inverter (10) may comprise three switch element groups connected in parallel. Each switch element group may comprise at least two switch elements connected in parallel. Each switch element may comprise an upper bridge-arm switch and a lower bridge-arm. The control panel (20) may generate a PWM waveform. The drive panel (30) may generate a drive voltage according to the PWM waveform to drive the upper bridge-arm switch and the lower bridge-arm switch of each switch element to conduct or break respectively, and to make the upper bridge-arms of the same switch element group to conduct or break simultaneously, and to make the lower bridge-arms of the same switch element group to conduct or break simultaneously. The present invention further discloses an electric motor comprising the same.

Abstract: When a short-circuit failure of any of switch portions (13) including switch elements (11) and parallel-connected feedback diodes (12) of an inverter circuit (7) is detected during the operation of a motor (1), a switch portion (13) where the short-circuit failure has occurred is checked for whether it is on the positive polarity side or the negative polarity side. The switch elements (11) are so controlled that all the switch portions (13) on the same polarity side as where the short-circuit has occurred are brought into a conducted state and all the others are disconnected. This prevents a large electric current from flowing into each switch portion of the inverter circuit without requiring any switch to block the power distribution between a motor and the inverter circuit when a short-circuit failure of the switch portion of the inverter circuit occurs.

Abstract: During motor acceleration control period that starts at time T1, if power supply output or supply current exceeds a predetermined level at time T2, PWM control in a PWM converter is turned off until a deceleration control period of T3 to T4 ends. As a result, DC link voltage (voltage of a power storage device) at the start of the deceleration control at time T3 drops to provide space for storing regenerative power; since the PWM control in the PWM converter is off during the deceleration control period, the regenerative power can be stored into the power storage device and reused in the next control cycle.

Abstract: Disclosed is a grid-connected inverter and a method for filtering AC output thereof. The grid-connected inverter comprises an AC output filter which includes two or more switchable filtering modules, power capacity of each filtering modules corresponding to a different output power of the grid-connected inverter; a monitoring module which is used to perform realtime monitoring on voltage and current outputted by the grid-connected inverter; and a control circuit which is used to calculate an output power grade of the grid-connected inverter according to the voltage and the current monitored by the monitoring module and control switching to the filtering module having a corresponding power capacity according to the power grade, the power grade being selected from a plurality of power grades which are divided according to power capacities of the filtering modules.