Abstract: The multi-level DC/AC converter, comprising: an input (5,7) connectable to a direct voltage source (3), with a first connection (5) and a second connection (7) between which can be applied an input voltage (Vi); a half-bridge with a first controlled switch (21) and a second controlled switch (25) between which is positioned an output (U) of the converter; a first connecting branch (15) between the first controlled switch (21) and the first connection (5) and a second connecting branch (17) between the second controlled switch (25) and the second connection (7); a third controlled switch (59) associated to the first controlled switch (21), connectable in series to the first controlled switch to generate an output voltage exceeding a first limit value (Vi/2); a fourth controlled switch (61) associated to the second controlled switch (25), connectable in series to said second controlled switch to generate an output voltage below a second limit value (?Vi/2).

Abstract: A power conversion device according to the aspects of the present technique is presented. The device includes a first converter and a second converter operatively coupled to the first converter. Moreover, the device includes a phase leg operatively coupled between the first converter, the second converter, where the phase leg includes a first unidirectional switch, a second unidirectional switch operatively coupled to the first unidirectional switch, and a first bidirectional switch, where a first end of the first bidirectional switch is operatively coupled to at least one of the first unidirectional switch and the second unidirectional switch.

Abstract: The present invention provides a high-power medium-voltage drive power cell, which comprises: a rectifier module for rectifying the three-phase AC input voltage to get a DC voltage; an IGBT (Insulated Gate Bipolar Transistor) inverter bridge connected to capacitors for converting the DC voltage into an AC voltage of which the frequency, the amplitude and the phase are adjustable; a bypass module connected to the IGBT inverter bridge for providing the bypass function when the IGBT inverter bridge works in an abnormal state; and a heat pipe heat sink having a base plate on both sides of which power elements of the high-power medium-voltage drive power cell are disposed.

Abstract: A method performed in a power bridge (3) comprising multiple arms (B1, B2, Bi, Bn). Each arm comprises upper and lower semiconductor switches arranged in series and connected in parallel to first and second terminals (B+, B?) of a common voltage source (2). The mid-point of the arm is connected to a phase of an electrical load (1). The aforementioned switches are controlled complementarily by pulses having a duty factor set value (RC1, RC2, RCi, RCn) determined as a function of a first phase voltage set value (V1, V2, Vi, Vn) in relation to a reference terminal of the electrical load (1) and of a common-mode voltage (V0) in relation to one of the first or second terminals, such as to control the switching losses of the switches. The common-mode voltage (V0) is determined such as to balance switching losses and conduction losses between the switches.

Abstract: In a power-system-interconnected inverter device, PI control circuits obtain voltage correction values in directions reducing the current errors on the basis of current errors serving as differences between target current values and detection values. Multiplexers provide modulation circuits with voltage target values corrected by the voltage correction values being added to voltage detection values. The modulation circuits provide gate signals for switch elements in multilevel circuits. In addition, a sign circuit provides gate signals for switch elements in a bridge clamping circuit.

Abstract: A solar photovoltaic power conversion system is provided to convert a DC input voltage into an AC output voltage, which mainly includes an input capacitor bank, a first switching circuit, a second switching circuit, a first filtering circuit, a second filtering circuit, and a control circuit. The first switching circuit has a first power switch and a second power switch. The second switching circuit has a third power switch and a fourth power switch. The control circuit produces a first control signal, a second control signal, a third control signal, and a fourth control signal to respectively control the first power switch, the second power switch, the third power switch, and the fourth power switch so as to reduce leakage current of the DC input voltage caused by parasitic capacitance voltage.

Abstract: A converter system and inverter system are disclosed with individual real and reactive power control for each phase of a poly-phase system. The converter system includes a controller, bidirectional single-phase inverters with AC sides coupled to an AC line filter and DC sides connected in parallel to a link capacitor coupled to DC/DC converters. Each inverter handles a separate AC phase. The controller controls the inverters and DC/DC converters so the current amplitude of each AC phase is independent, and the phase difference of each AC phase is independent. The inverters can be galvanically isolated between the DC and AC sides. The inverters can be non-isolated inverters having line and neutral connectors coupled to an isolated transformer winding, and the output windings of the transformer can be wired in a Wye configuration. The inverters can have local controllers.

Abstract: The power conversion device includes a plurality of semiconductor modules, each having a main body section including a switching element therein. In a module unit, a positive module and a negative module are disposed such that main surfaces of the respective main body sections oppose each other. A positive terminal, a first intermediate terminal, a negative terminal, and a second intermediate terminal project in a Z direction perpendicular to X direction in which the positive module and the negative module oppose each other. A first vector V1 from the positive terminal towards the first intermediate terminal and a second vector V2 from the second intermediate terminal towards the negative terminal are configured such that these vector components V12 and V22 in a Y direction perpendicular to both the X and Z directions are opposite to each other.

Abstract: An architecture for current-modulating power-handling circuits, such as power converters, where a small saturating inductance is used to obtain a pulse edge when the main current value crosses zero.

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: In an inverter device, a first three-level circuit includes first to fourth preceding-stage switch elements connected in series between a first input end and a ground and a first charging and discharging capacitor. A second three-level circuit includes fifth to eighth preceding-stage switch elements connected in series between a second input end and the ground and a second charging and discharging capacitor. The first and second two three-level circuits define a five-level circuit that is subjected to switching with the carrier frequency of PWM modulation. The output polarity of a subsequent-stage bridge clamping circuit is inverted between the anterior half cycle and the posterior half cycle of a power supply frequency.

Abstract: A three-level driver circuit for an inverter half-bridge includes an output inverter half-bridge, which has four switches in series. The switches are controlled by signals from a switch controller applied via gate drivers. Switch delay times are taken into consideration to prevent short-circuiting when dimensioning the switching constellations of the switches.

Abstract: A half-bridge of a bidirectional converter is divided into a first and a second conduction path connected in parallel. In each of the conduction paths a switching element and a freewheeling diode are connected in series, and the center points of the conduction paths are connected via a second inductor. The second inductor is connected in series with a first inductor which is connected to the center point of the second conduction path. The half-bridge has two operating modes. In each of the two operating modes the switching element in one of the two conduction paths is clocked at a high frequency to cause a flow of energy in one of two directions between a pair of high voltage-side connections and a pair of low voltage-side connections to the half-bridge. The two switching elements are of different types, the switching element in the first conduction path causing higher switching losses.

Abstract: A power conversion device includes a main circuit unit (direct-current main circuit) that converts direct-current power into alternating-current power, and a control unit that controls the direct-current main circuit. The direct-current main circuit includes a voltage detector (detector) that detects a capacitor voltage and a discharge circuit that discharges energy accumulated in a capacitor. The control unit includes a detection circuit that estimates a capacitor voltage during a normal operation based on a voltage transmitted from the voltage detector in a state where the main circuit unit is disconnected from a power supply and that detects a sign that a short circuit fault occurs in the capacitor, and a control circuit that outputs a control signal for controlling the discharge circuit to operate when the control circuit receives a detection signal from the detection circuit.

Abstract: A DC to AC converter includes a first switch, a second switch, a first half bridge inverter, and a second half bridge inverter. The first switch includes a first terminal and a second terminal. The second switch includes a first terminal and a second terminal. A portion between the first terminal of the first switch and the first terminal of the second switch is operable to receive a direct current power source. The first half bridge inverter includes a first terminal, a second terminal, and an output terminal. The second half bridge inverter includes a first terminal, a second terminal, and an output terminal. A portion between the output terminal of the first half bridge inverter and the output terminal of the second half bridge inverter is operable to output an alternative current.

Abstract: A power conversion apparatus includes: an inverter unit having high and low potential-side switching elements corresponding to each phase of a winding of a rotating electrical machine; a current detecting unit; a current obtaining unit obtaining a current detection value with a fixed interval sampling timing; and a control unit controlling the switching elements based on a PWM reference signal and a duty instruction value. The control unit includes: a phase current computing device; a voltage instruction value computing device; and a duty computing device. The phase current computing device computes a correction current based on positive and negative side corrected current detection values. The positive-side corrected current detection value is obtained when a duty is adjusted to a positive side, and the negative-side corrected current detection value is obtained when the duty is adjusted to a negative side.

Abstract: A method and apparatus for line-cycle storage of a single-phase cycloconverter. The method includes receiving input power from an input port of the singe-phase cycloconverter and monitoring an AC output port of the single-phase cycloconverter. The method measures energy stored in a line-cycle energy storage circuit coupled to one line of the AC output port of the single-phase cycloconverter, and determines a phase difference between a monitored AC voltage of the AC output port and the measured voltage of the line-cycle energy storage circuit. The method controls switches in the single-phase cycloconverter to selectively store energy in the line-cycle energy storage circuit based on the phase difference.

Abstract: Systems and methods are provided for regulating the state of charge of a battery. An exemplary electrical system includes a fuel cell coupled to a bus and a battery coupled to the bus via a switching arrangement coupled to a capacitor. An exemplary method for operating the electrical system involves operating the switching arrangement such that a voltage of the battery is substantially equal to a voltage of the fuel cell when a state of charge of the battery is greater than a lower threshold value and less than an upper threshold value, and operating the switching arrangement to couple the capacitor electrically in series between the battery and the bus when the state of charge of the battery is not between the lower threshold value and the upper threshold value.

Abstract: An inverter and a direct current (DC) bus voltage regulating method thereof are provided. The inverter includes a resonant conversion circuit, an inverting circuit, a first control circuit and a second control circuit. The resonant conversion circuit receives a DC input voltage and converts the same into a DC bus voltage. The inverting circuit couples to the resonant conversion circuit, and configured to convert the DC bus voltage into an AC output voltage. The first control circuit is configured to control operations of the resonant conversion circuit, where the first control circuit calculates a best working voltage of the resonant conversion circuit based on the DC input voltage and a resonant frequency of the resonant conversion circuit. The second control circuit controls operations of the inverting circuit, where the second control circuit receives the best working voltage calculated by the first control circuit and regulates the DC bus voltage accordingly.

Abstract: A power conversion device includes a first capacitor connected in parallel to a direct-current power supply, plural power converters that drive plural synchronous machines, a second capacitor connected in parallel to a direct-current side of power converters, a switching circuit inserted between the first and second capacitors, a switch-start instruction unit that controls starting of an operation of the power converters, and a control unit that controls the power converters based on a motor velocity and a voltage of the first capacitor. The switch-start instruction unit turns off the switching circuit while the power converters stop, turns off the switching circuit until a terminal voltage of each of the synchronous machines becomes equal to a predetermined value when each of the power converters starts operating, and turns on the switching circuit when the terminal voltage of each synchronous machine becomes equal to or smaller than the predetermined value.

Abstract: A CT system includes an x-ray source, a high-voltage (HV) tank coupled to the x-ray source, and an inverter coupled to the HV tank. The inverter includes an H-bridge configuration of switches comprising a first leg and a second leg, wherein the first and second legs include respective upper and lower switches, and at least one additional leg of switches having respective upper and lower switches. The system includes a controller configured to interleave switch operation between the H-bridge configuration and the at least one additional leg of switches.

Abstract: An arrangement which includes two or more energy storage units for electrical energy connected in series, and two or more balancing resistor units. Each balancing resistor unit is connected in parallel with one of the energy storage units. The arrangement also includes means for determining a voltage over all of the series-connected energy storage units and means for determining the energy storage unit voltages between poles of the energy storage units. One or more of the balancing resistor units include a base resistor unit and a control resistor unit connected in series and a switching device connected in parallel with the control resistor units.

Abstract: A power conditioning unit for delivering power from a power source to a mains utility supply, the power conditioning unit comprising a plurality of input terminals for connecting to the power source, a plurality of output terminals for connecting to the mains utility supply, a voltage increasing converter connected to the input terminals, a voltage reducing converter connected to the voltage increasing converter and a dc-to-ac converter connected to the voltage reducing converter and to the output terminals.

Abstract: Battery energy storage arranged to be connected to a direct current capacitor, which is connected in parallel to a power converter. The battery energy storage includes a battery module and a controllable voltage source adapted to inject a voltage opposite to a voltage ripple of the direct current capacitor. A power system including such battery energy storage and a direct current capacitor is also disclosed.

Abstract: In a power inverter, a coolant passage is fixed to a chassis to cool the chassis; the chassis is divided into a first region and a second region by providing the coolant passage in the chassis; a power module is provided in the first region as fixed to the coolant passage; a capacitor module is provided in the second region; and the DC terminal of the capacitor module is directly connected to the DC terminal of the power module.

Abstract: A modular voltage source converter (100) comprises a plurality of cells conformal to a basic cell design comprising a first and a second terminal, a capacitor and at least two switches arranged in a half-bridge or full-bridge configuration. In the converter, a first group is formed by a number n of cells (101-k, k=1, . . . , n) connected serially at their terminals, and a second group is formed by an equal number n of cells (102-k, k=1, . . . , n) connected serially at their terminals. The terminals of the cells (101-k) in said first group are connected, via a resistive or inductive connection element (110-k), to the terminals of corresponding cells(102-k) in said second group.

Abstract: A transistor-based full-wave bridge rectifier is suitable for low A.C. input voltages such as received by a Radio-Frequency Identification (RFID) device. Voltage drops due to bridge diodes are avoided. Four p-channel transistors are arranged in a bridge across the A.C. inputs to produce an internal power voltage. A comparator receives the A.C. input and controls timing of voltage boost drivers that alternately drive gates of the four p-channel transistors with voltages boosted higher than the peak A.C. voltage. Four diode-connected transistors are connected in parallel with the four p-channel bridge transistors to conduct during initial start-up before the comparator and boost drivers operate. Substrates are connected to the power voltage on the power-voltage half of the bridge and to the A.C. inputs on the ground half of the bridge to fully shut off transistors, preventing reverse current flow. The transistor bridge can be integrated onto system chips.

Abstract: Disclosed is an inverter having improved power conversion efficiency. The inverter (200) converts direct current power supplied from a plurality of direct current power supplies (V1, V2) having different voltages into alternating current power. The inverter (200) is provided with a control unit (20). The control unit (20) generates modified sine waves using a power supply voltage (E1) of the power supplied from the first direct current power supply (V1), a power supply voltage (E2) of the power supplied from the second direct current power supply (V2), and a potential difference (E1?E2) between the two power supply voltages. The control unit (20) generates the modified sine waves by controlling H bridge circuits provided for the direct current power supplies (V1, V2), respectively.

Abstract: A circuit for a phase connection of an inverter includes upper and lower bridge halves and respectively associated upper and lower bridge segments. Each bridge half has an outer switch and an inner switch connected in series. Each bridge segment has a diode and the inner switch of the associated bridge half connected in series. An output of the circuit is respectively connected to upper and lower potentials through the outer switches and is further connected to a center potential applied between the upper and lower potentials through each of the upper and lower bridge segments. Each bridge half further has a parallel power switch. The parallel switch of each bridge half is connected in parallel to the series-connected outer and inner switches of the bridge half. The output of the circuit is further respectively connected to the upper and lower potentials through the parallel switches.

Abstract: A method for operating a multi-phase modular power inverter having DC input terminals and AC phase voltage output terminals connected to a load, phase modules connected between the DC input terminals, with each phase module composed of valve arms connected in series at a connection point forming an AC phase voltage output terminal which is connected to a load, each valve arm having a plurality of power inverter cells with turn-off semiconductor switches and a choke connected in series, includes controlling, with a control device, the turn-off semiconductor switches of each power inverter cell as a function of a plurality of setpoint values, wherein the setpoint values are generated such that a time-averaged energy value stored in a capacitor of a corresponding power inverter cells is predetermined by an operating point of the load and-or an operating mode of the modular multi-level power inverter.

Abstract: A power converter can be configured of a first series circuit, formed from a first semiconductor switching element and a second semiconductor switching element connected in series to either end of a direct current voltage supply series circuit formed from a first direct current voltage supply and a second direct current voltage supply connected in series, and a second series circuit, formed from a third semiconductor switching element and a fourth semiconductor switching element connected in series between a connection point of the first direct current voltage supply and the second direct current voltage supply and a connection point of the first semiconductor switching element and the second semiconductor switching element. The first semiconductor switching element and the third semiconductor switching element can be configured of a first semiconductor device, and the second semiconductor switching element and the fourth semiconductor switching element can be configured of a second semiconductor device.

Abstract: There is provided a method and control system for reducing noise in a power converter by controlling a switching device in the power converter according to a modulation scheme. The switching device couples a direct current (DC) source to provide an alternating current (AC) output at a particular switching frequency. The method includes the step of, in each switching period, switching the switching device between active configurations providing a finite voltage at the output and inactive configurations providing a zero voltage at the output. The ratio between the total period of time in which the switching device is in an active configuration and the total period of time in which the switching device is in an inactive configuration is the same for each switching period and is determined according to the desired voltage at the AC output.

Abstract: A controller (2) and a method for a DC converter (1), wherein the DC converter (1) comprises an input (E), an output (A), a connection to ground (GND), and also at least two half-bridges with two switching elements each (TR1 . . . TR4) connected in series and an inductance (L1, L2) each connected with the point connecting the two switching elements. In accordance with the invention the controller (2) is equipped to measure the current (IL1, IL2) through the inductances (L1, L2), and controls the switching elements (TR2, TR4)/(TR1, TR2) positions on the ground side/input side always with negative/positive current through the inductance (L1, L2) into an off-state. Finally a DC converter (1) connected with the controller (2) is also specified.

Abstract: Photovoltaic power converter systems and methods are described. In one example, a method for use in operating a solar power converter includes sampling a DC link voltage of a DC link during a first cycle of an alternating output voltage of a second stage at one instance when the alternating output voltage is crossing zero volts in a first direction. A voltage difference a voltage difference between the DC link voltage sampled during the first cycle and a DC link voltage sampled during a previous cycle when the alternating output voltage was crossing zero volts in the first direction is determined. A DC link power is estimated based at least in part on the determined voltage difference. The AC power output by the second stage in a second cycle is controlled based at least in part on the estimated DC link power.

Abstract: The present disclosure relates to a controller, a circuit and method for controlling a power converter using pulse width modulation (PWM). At least one logic block (13, 15, 16) of the controller is configured to remove a command (4) which is configured to control the other power semiconductor switch (2) in a half-bridge (1,2) so that the other power semiconductor switch (2) remains in a non-conductive state while an antiparallel diode (6) allows an electric current (5) to pass in one direction, called the diode's forward direction, while blocking current in the opposite direction. In case the diode (6) is conducting instead of the other power semiconductor switch during the duration of the state of the command, the switching command (4) for the latter is omitted.

Abstract: An inverter device includes a switch circuit configured by series-connecting two N-channel semiconductor switching elements in opposite directions so that the switch circuit makes or breaks electrical connection between a DC power supply and an inverter circuit and a control circuit carrying out a protecting operation in which when the control circuit output a control signal to control switching of the inverter circuit and an operating condition is met, the control circuit stops output of the control signal to turn off all switching elements configuring the inverter circuit and the switch circuit. In the protecting operation, the switch circuit is turned off after output of the control signal has been stopped.

Abstract: In accordance with a preferred embodiment of the present invention, an inverter circuit includes a direct current (DC)-to-DC power converter configured to receive an input energy from a device via a first input terminal and a second input terminal, where the DC-to-DC power converter is configured to convert a first portion of the input energy to a DC energy. The inverter circuit also includes an inverter stage coupled to an output of the DC-to-DC power converter, and is connected to the first input terminal of the DC-to-DC power converter and the second input terminal of the DC-to-DC power converter, where the inverter stage is configured to convert a second portion of the input energy to a first output energy.

Abstract: A current-source power converting apparatus in an embodiment includes a current-reference generating unit, a polarity determining unit, a PWM-pulse-signal generating unit, and a drive-signal generating unit. The current-reference generating unit outputs a phase current reference and a line-to-line current reference. The polarity determining unit determines a polarity of the phase current reference. The PWM-pulse-signal generating unit generates a PWM pulse signal by comparing the line-to-line current reference and a carrier signal. The drive-signal generating unit generates a drive signal that drives each of a plurality of switching elements, based on the PWM pulse signal and a polarity of the phase current reference.

Abstract: A power conversion circuit converting DC electric power into AC electric power and sending the AC power to an inductive load, includes a first switching device connected to the DC power supply; a second switching device connected to the DC power supply; a first inductor provided between the first switching device and the inductive load; a second inductor provided between the second switching device and the inductive load; and a clamping diode connected between a first connection point between the first switching device and the first inductor, and a second connection point between the second switching device and the second inductor. When the first and second switching devices are turned off, a current flows through the second diode, clamping diode, first inductor and inductive load to completely flow out a current in the first inductor, and then a current flows through the second diode, second inductor and inductive load.

Abstract: A power supply device of the invention includes a first switching leg including first and second switching elements between DC terminals; a second switching leg including third and fourth switching elements between the DC terminals; a first capacitor leg including first and second capacitors between the DC terminals; a second capacitor leg including third and fourth capacitors between AC terminals; a first inductor between a connection of the first and second switching elements and one of the AC terminals; a second inductor between a connection of the third and fourth switching elements and another of the AC terminals; a controller; an AC power supply connected to the AC terminals and the connection of the third and fourth capacitors; and a DC power supply between the DC terminals, wherein the controller charges the first and second capacitors to a voltage higher than a voltage crest of the AC power supply.

Abstract: A multilevel inverter circuit includes an inverter control circuit that controls switching of main and neutral switches. The inverter control circuit receives current vector information indicating flow direction of an AC current output of the multilevel inverter circuit. The inverter control circuit eliminates dead time between switching of a neutral switch and a main switch depending on whether the AC current output is flowing towards a load or away from the load. Among other advantages, elimination of dead time improves the total harmonic distortion of the sinusoidal AC voltage output of the multilevel inverter circuit.

Abstract: In a filter capacitor including three capacitor elements including a first capacitor element at an end on one side in an electrical connection form and a second capacitor element at an end on the other side, a pair of direct-current terminals including a positive-electrode-side main terminal and a negative-electrode-side main terminal, which receive a direct-current voltage from a direct-current power supply, are provided, a first conductor path length between a positive-electrode-side terminal of the first capacitor element and the positive-electrode-side main terminal and a second conductor path length between a positive-electrode-side terminal of the second capacitor element and the positive-electrode-side main terminal are approximately the same, and a third conductor path length between a negative-electrode-side terminal of the first capacitor element and the negative-electrode-side main terminal and a fourth conductor path length between the negative-electrode-side terminal of the second capacitor eleme

Abstract: A semiconductor module includes a plurality of power semiconductor elements forming upper arms and lower arms of a plurality of sets of half bridge circuits; a plurality of control circuits on/off driving each power semiconductor element having a control terminal of the plurality of power semiconductor elements; and a power supply terminal and a plurality of control terminals, connected to a plurality of respective external connection control terminals. Low potential side electrodes of the power semiconductor elements forming the respective upper arms of the plurality of sets of half bridge circuits and high potential side electrodes of the power semiconductor elements forming the respective lower arms of the plurality of sets of half bridge circuits are individually connected to a plurality of respective external connection output terminals.

Abstract: A photovoltaic (PV) system is disclosed that provides dynamic regulation of the output of a PV array such that the inverter can safely operate without entering a voltage protection mode. The PV system includes a PV array that generates a direct current (DC) output from received solar radiation and a DC link coupled to the PV array to receive the DC output therefrom. The PV system also includes a DC-to-AC power inverter electrically coupled to the DC link to receive the DC output therefrom and invert the DC output to an AC output and a damping circuit electrically coupled to the DC link and positioned between the PV array and the DC-to-AC power inverter. The damping circuit includes a damping resistor and a damping switch.

Abstract: The invention is a method of tracking the overall maximum power point of a grounded bipolar photovoltaic array by tracking and regulating the voltage of the weaker of the two monopolar subarrays at any instant in time. The transfer between subarrays being tracked for the maximum power point is seamless when the voltage of one subarray becomes lower than the other. This tracking method insures stable operation and maximum power transfer under all balanced and unbalanced PV array conditions. This tracking algorithm would typically be part of a larger digital power converter control system.

Abstract: A multilevel inverter includes a first half bridge in series with a second half bridge, each comprising a switch having a channel. The switch is configured to block a substantial voltage in a first direction during a first mode of operation, to conduct substantial current through the channel in the first direction during a second mode of operation, and to conduct substantial current through the channel in a second direction during a third mode of operation. During the third mode of operation, a gate of the switch is biased relative to a source of the switch at a voltage that is less than a threshold voltage of the switch. The inverter may also include a third half bridge. The inverter can be configured such that in operation, switches of the third half bridge are switched at a substantially lower frequency than the switches of the first and second half bridges.

Abstract: A method for controlling a polyphase inverter that includes a number of half bridges connected into an intermediate voltage circuit and center taps between switching elements. By cyclically switching the switching elements, the respective center taps of the half bridges are connected to an upper intermediate circuit rail or to a lower intermediate circuit rail of the intermediate voltage circuit according to the principle of pulse width modulation. The switching elements of at least one half bridge are driven in a modified manner, at least in some time intervals, in that the switching pulses of at least two consecutive periods of the pulse width modulation are concatenated directly in time as one switching pulse. In this way, the switching frequencies of the correspondingly driven switching elements and thus the switching losses of the latter can be further reduced.

Abstract: In some aspects of the invention, multiple insulating substrates each mounting thereon at least one each of at least four semiconductor devices that form at least one of three-level electric power inverter circuits and a base plate on the one surface of which a plurality of the insulating plates are arranged are provided. On the one surface of the base plate, at least four regions are established and multiple insulating substrates are arranged to be distributed so that at least one each of the at least four semiconductor devices is arranged in each of the four regions established on the base plate. This can make the semiconductor devices arranged to be distributed so that heat generating sections determined according to the operation mode of the semiconductor system comes to be partial to disperse generated heat, by which a semiconductor system is provided which can enhance heat dispersion efficiency.

Abstract: A main circuit of a three-level active neutral point clamped voltage source converter having a pair of additional main switches provides two paths between an output node and a neutral point in which one of the paths involves only switches of an inner pair of switches that are operated at a high frequency. An auxiliary circuit operating at a high frequency for only a brief period during each high frequency switching cycle selects the path involving only the inner switches and provides operation with zero voltage switching and avoids reverse recovery of diodes connected antiparallel with the main and additional main switches. Accordingly, turn-on switching losses in the main switches is avoided and the voltage source converter can be operated at increased frequency to allow reduction in size of magnetic components and full potential power transfer to be achieved.

Abstract: On an inverter (1) for converting an electric direct voltage, in particular of a photovoltaic direct voltage source into an alternating voltage with a direct voltage input with two terminals (DC+, DC?) and one alternating voltage output with two terminals (AC1, AC2) and with one bridge circuit including semiconductor switching elements (S1-S6), said bridge circuit comprising one first bridge branch (Z1) including four switching elements (S1-S4) and one second bridge branch (Z2) including two additional switching elements (S5, S6) as well as a freewheeling circuit provided with additional diodes (D7, D8), the efficiency is further increased without high frequency interferences and capacitive leakage currents having the possibility to occur on the generator side.