Abstract: A method and apparatus are provided for operating a converter circuit, which includes at least two phase modules each having first and second subconverter systems, which include power semiconductor switches. The switches of the first and second subconverter systems are driven by first and second drive signals, respectively. To enable dimensioning a capacitive energy store of the converter circuit to be independent of a desired current at an output connection of the converter circuit, for each phase module, the first and second drive signals are respectively formed from a voltage signal across inductances and a switching function for the switches of the first and second subconverter systems, respectively. The switching functions are formed by a voltage signal corresponding to the voltage at the output connection and a selectable reference signal. The voltage signals are selected to be in phase with the voltage at the output connections of the phase modules.

Abstract: A method and system for controlling a power converter system with a direct current (DC)-bus capacitor connected to at least a first converter and a second converter. The first converter is with associated first current and the second converter is with associated second current. Switching states of the first and second converters are determined. The switching states of the second converter are sequenced relative to the first converter to reduce a difference of sums of the associated first and second currents between adjacent time intervals.

Abstract: A direct current (DC)/DC converter capable of lowering power consumption and capable of being started in a short time is provided. A voltage generated at a second output capacitor is input to a power supply terminal. An input voltage is input to a high voltage terminal. A charging transistor is a N-channel Metal Oxide Semiconductor Field Effect Transistor disposed between the high voltage terminal and the power supply terminal and applied with a bias so that the charging transistor is normally on. In a first state, in which the voltage of the power supply terminal is lower than a specified first threshold voltage, a current limiting circuit limits a charging current flowing from the high voltage terminal to the power supply terminal, and in a second state in which the voltage is higher than a second threshold voltage, the current limiting circuit lowers the charging current substantially to zero.

Abstract: Systems and methods for a fault protection are provided that can be implemented in a hybrid electric vehicle (HEV) to limit the magnitude of a current that flows when an AC-to-chassis fault (ACF) occurs between an AC connection and the chassis of the HEV. An electric machine having a winding, an inverter sub-module (ISM) having a first switch and a second switch, and fault protection elements (FPEs), coupled to the ISM, are provided. The winding is coupled to the ISM coupled via the AC connection. The FPEs can include, for example, first and second inductances. To limit the magnitude of the current, the current can be passed along a first current path that includes the second inductance when the first switch is closed, and can be passed along a second current path that includes the first inductance when the second switch is closed.

Abstract: The invention relates to a method for operating an inverter (1), in particular a pulse-controlled inverter, comprising multiple phase systems (2, 3, 4), each of which has an outer conductor (7, 8, 9) and at least one semiconductor component (12, 13), and a temperature monitoring device (15) that has multiple temperature sensors (16, 17, 18) which sense the temperature of at least one part of at least one of the phase systems (2, 3, 4). In said method, a temperature gradient is determined from each of the sensed temperatures, the difference of the determined temperature gradients from an estimated gradient value is ascertained, and if the difference exceeds a threshold value, a fault of the inverter (1), in particular of a cooling device of the inverter (1), is identified. The invention further relates to an inverter (1).

Abstract: Aspects of the invention are directed to a gate driving circuit for a power conversion circuit having an upper and lower arm circuit composed of series-connected upper arm and a lower arm, each arm including two or more semiconductor switching devices connected in series. In some aspects, a gate driving circuit of the invention includes a circuit of series connection including a diode and a resistor between a positive potential side of a positive side power supply and a positive electrode side. The gate driving circuit can determine a short-circuit fault of the semiconductor switching device that is connected to the gate driving circuit by detecting the current that flows through the circuit of series connection including the diode and the resistor when an OFF command of ON/OFF command signals is given to the semiconductor switching device.

Abstract: A system for improving wind turbine generator performance is disclosed. In one aspect a rotary power generation system is provided, including: a rotary power generator for generating variable-frequency alternating currents; a negative sequence current regulator that determines and uses frequency-dependent D-axis and Q-axis negative sequence gains based on an electrical frequency of the rotary power generator; and a system for controlling voltage components for balancing the variable-frequency alternating currents generated by the rotary power generator based on the selected D-axis and Q-axis negative sequence gains.

Abstract: The invention relates to a method for operating an inverter (1), in particular a pulse-controlled inverter, comprising multiple phase systems (2, 3, 4), each of which has an outer conductor (7, 8, 9) and at least one semiconductor component (12, 13), and a temperature monitoring device (15) that has multiple temperature sensors (16, 17, 18) which sense the temperature of at least one part of at least one of the phase systems (2, 3, 4). In said method, a temperature gradient is determined from each of the sensed temperatures, the difference of the determined temperature gradients from each other is ascertained, and if the difference exceeds at least one threshold value, a fault of a cooling device of the inverter (1) is identified. The invention further relates to an inverter (1).

Abstract: A switching power source device includes a switching power supply main body switching an input voltage via a switching element to obtain a predetermined DC output voltage, a control circuit performing on/off-driving of the switching element; and a capacitor connected to the control circuit to be charged by an external power supply via an activation switch circuit during activation and charged by a voltage generated in the switching power supply main body after completion of activation to supply a control power voltage to the control circuit. The control circuit further includes a latch circuit set according to a latch signal emitted when an abnormality is detected, to stop the driving of the switching element, a discharge circuit receiving the latch signal to be turned on and discharging charges accumulated in the capacitor, and a comparator resetting the latch circuit when the control power voltage decreases to an operation stop voltage.

Abstract: A power conversion apparatus includes: a line breaker that is connected in series to a direct-current power supply; a first capacitor that is connected in parallel to the direct-current power supply through the line breaker; a discharge circuit that includes a resistor and a first switching circuit connected in series and is connected in parallel to the first capacitor; a power converter for driving a synchronous machine; a second capacitor that is connected in parallel to a direct-current side of the power converter; a second switching circuit that is connected in series between the first capacitor and the second capacitor; and a control circuit for controlling the discharge circuit. The control circuit controls the discharge circuit on the basis of the voltage of the first capacitor and the voltage of the second capacitor.

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, wherein the inverter is configured to supply power to an electrical distribution network. A control system is coupled to at least one of the converter and the inverter, wherein the control system is configured to adjust an operation of the at least one of the converter and the inverter to reduce the voltage across the bus during at least one of a low voltage event and a high voltage event.

Abstract: A circuit for controlling a latch mode of a pulse width modulation circuit includes a D flip-flop, a voltage generation unit, a comparator, and a logic unit. The D flip-flop generates a switch control signal according to a latch enable signal. The voltage generation unit generates a discharge current, and a voltage divider resistor group included in the voltage generation unit generates a first voltage when the voltage generation unit is turned on according to the switch control signal. A voltage of a predetermined pin of the pulse width modulation circuit is equal to a predetermined voltage when the discharge current is equal to the charge current. The comparator compares a reference voltage with the first voltage to generate a comparison signal. The logic unit generates a clear signal according to the comparison signal. The D flip-flop clears the switch control signal according to the clear signal.

Abstract: The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing/blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.

Abstract: Systems and methods are provided for controlling an uninterruptible power supply (UPS) to transition between three- or higher-level operation and two-level operation in a neutral-point-clamped (NPC) inverter. In an example, a UPS system includes an NPC inverter and a controller. The NPC inverter may supply power to a load. The controller may control the inverter to operate in a three-level mode or higher when the load is substantially balanced and to operate in a two-level mode when the load is substantially unbalanced.

Abstract: An overheating protection control apparatus for an inverter driving a rotating electric machine comprising: a temperature sensor for measuring the temperature of a power control element in the inverter, and a control device restricting the load factor of the rotating electric machine when the temperature measured by the temperature sensor reaches a threshold value. The control device modifies the threshold value based on a parameter affecting heat radiation or cooling of the inverter. Preferably, the inverter includes a plurality of power control elements. The temperature sensor detects the temperature of one or more, but not all of the plurality of power control elements. The parameter is a physical quantity affecting the temperature difference between the one or more power control elements and another power control element included in the inverter. Preferably, the inverter is cooled by a coolant medium. The parameter is the temperature of the coolant medium.

Abstract: Aspects of the invention are directed to a protection control system of the invention is a protection control system for a multilevel power conversion circuit of a flying capacitor type, the power conversion circuit including six semiconductor switches of first through sixth semiconductor switches sequentially connected in series from a positive terminal to a negative terminal of a DC power supply, a first capacitor connected between the connection point of the second and third semiconductor switches and the connection point of the fourth and fifth semiconductor switches and a second capacitor connected between the connection point of the first and second semiconductor switches and the connection point of the fifth and sixth semiconductor switches, wherein the protection control system of the invention turns ON the second semiconductor switch or maintains the second semiconductor switch in an ON state, in the case of short-circuit fault of the third semiconductor switch.

Abstract: The number of constituent components is reduced so as to provide a small-size and inexpensive electric-power conversion system.

Abstract: The present disclosure provides systems and methods for protecting a switch mode power supply (SMPS). An SMPS may include an input power connector, an input rectifier and filter, a transformer, an output rectifier and filter, and an output power connector. A control circuit may selectively generate a switching signal for driving the transformer based on a feedback signal and a protection signal generated by a protection circuit. The protection circuit may generate the protection signal with an asymmetric duty cycle oscillating between an enable state and an inhibit state. The protection signal may inhibit the control circuit from generating the switching signal when the protection signal is in the inhibit state. A detection circuit may receive the feedback signal and selectively force the protection signal to the enable state when the feedback signal indicates that an output voltage is too high.

Abstract: A converter circuit includes a transformer having a first side and a second side. The converter circuit also includes a switch coupled to the first side of the transformer. The converter circuit further includes a rectifying diode coupled to the second side of the transformer and to a first output terminal of the converter circuit. In addition, the converter circuit includes a clamping diode coupled to the second side of the transformer, to the rectifying diode, and to a second output terminal of the converter circuit. The converter circuit may include a boost section and a flyback section. The converter circuit may also include an active clamp and an isolated flyback section.

Abstract: A power converter converts DC power supplied from a first DC power supply and a second DC power supply into AC power and supplies the AC power to a load. The power converter includes a protection circuit for allowing a charging current, which is possibly to flow from the first DC power supply and the second DC power supply to a first snubber capacitor or a second snubber capacitor, to flow to another current path, when a voltage applied to the first snubber capacitor becomes a predetermined value or more or when a voltage applied to the second snubber capacitor becomes a predetermined value or more.

Abstract: Subject of the invention is a multi-resonance power supply with integral quality factor limiter, designated for transformation of direct voltages, characterised by high immunity to overload and rapid load changes. The power supply has the (TS) isolating transformer, with its primary winding connected to the main (OR) resonant circuit having at least one node connected with the set of (K1), (K2) current switches, via the serial resonant circuit, whereby at least one component of the serial resonant circuit is connected to the (DON) diode voltage limiter.

Abstract: An active snubber circuit for a power converter, a method of operating the same and an inductor inductor capacitor converter incorporating the circuit or the method. In one embodiment, the circuit includes: (1) a series-coupled first capacitor and diode associated with a secondary-side switch in the power converter and coupled to an output thereof and (2) an active snubber circuit switch coupled in parallel with the diode and configured to receive a control signal that closes the active snubber circuit switch during at least a portion of a time during which the secondary-side switch is open.

Abstract: A power isolation system and method is disclosed. The system includes a transformer suitable for use in the power isolation system, and a semiconductor device electrically connected to the transformer to provide a reduction of the inrush current associated with powering the transformer, wherein the semiconductor device is activated upon power up based upon the previous shutdown state of the power isolation system to provide a soft start to the transformer, and after activation of the transformer, the semiconductor device is shorted in the system.

Abstract: A saturation prevention circuit includes a first controlled current source, a second controlled current source, an integrating capacitor, and a comparator. The first controlled current source generates a first current that is proportional to an input voltage that is to be applied to a winding of a transformer. The second controlled current source generates a second current that is proportional to a reset voltage that is to be applied to the winding. The capacitor is charged with the first current while the input voltage is applied to the winding of the transformer and discharged with the second current while the reset voltage is applied to the winding. The comparator compares a voltage on the integrating capacitor with a first threshold and generates a first signal to immediately turn off the switch when the voltage on the integrating capacitor reaches the first threshold to limit a magnetic flux in the transformer.

Abstract: A short circuit detection device is provided to check a circuit layout. The circuit layout includes electronic components connected in parallel. Any of the electronic components includes two contacts on the circuit layout. The short circuit detection device includes a determination circuit configured to determine whether a short circuit has occurred in the circuit layout, and a detection circuit configured to determine the specific electronic component or components responsible for the short circuit. The determination circuit connects with one contact of any of the electronic components. The detection circuit connects with two contacts of any of the electronic components.

Abstract: The present invention provides a safe circuit that can prevent an arm short, when a half-bridge circuit is configured by using a normally-on switching element, and the half-bridge circuit is used as a driver circuit or an inverter circuit. In a driver circuit configured by a half-bridge circuit in which one of input and output terminals of a first switching element 14 is connected to a first power-supply voltage V1 on a high-voltage side, and the first switching element 14 and a second switching element 15 are connected in series, a normally-off third switching element 16 is inserted between the second switching element 15 and a second power-supply voltage V2 on a low voltage side. The third switching element 16 is turned off, when an operating voltage VH or VL supplied from control-circuit power supplies 13a and 13b is insufficient for the operation of a control circuit 11.

Abstract: An alternating current-to-direct current (AC-to-DC) power supply has a first stage providing a first DC voltage and a second stage providing a second DC voltage. The AC-to-DC power supply has a first efficiency at the first stage and a second efficiency at the second stage that is less than the first efficiency. The second DC voltage is also less than the first DC voltage. A blower is electrically connected to the first stage of the AC-to-DC power supply to receive the first DC voltage from the AC-to-DC power supply to power the blower. Electrical connection of the blower to the first stage of the AC-to-DC power supply instead of to the second stage of the AC-to-DC power supply wastes less power and is more efficient.

Abstract: A control circuit, during a positive period in which current flows from a power conversion apparatus to a load, causes a second snubber capacitor to discharge by controlling a second auxiliary switch to be turned on while a second main diode is turned on, and during a negative period in which current flows from the load to the power conversion apparatus, causes a first snubber capacitor to discharge by controlling a first auxiliary switch to be turned on while a first main diode is turned on.

Abstract: An overvoltage protection circuit is provided for at least one branch of a half-bridge which includes a controllable semiconductor switch element and a free-wheeling diode connected in series and situated on a common circuit substrate. The protection circuit includes a commutation branch connected in parallel with the half-bridge branch, the commutation branch including at least one commutation capacitor also situated on the circuit substrate.

Abstract: According to an exemplary implementation, a power module package includes a multi-phase inverter. The power module package also includes a multi-phase inverter driver configured to drive the multi-phase inverter. The power module package further includes a power factor correction (PFC) circuit where the PFC circuit is configured to regulate a bus voltage of the multi-phase inverter and a PFC driver configured to drive the PFC circuit. The multi-phase inverter, the multi-phase inverter driver, the PFC circuit, and the PFC driver are situated on a package substrate of the power module package. The multi-phase inverter driver and the PFC driver can be in a common driver integrated circuit (IC).

Abstract: It is an object to provide a DC/DC converter that can stabilize power supply potential in use. It is another object to provide a semiconductor device in which circuit operation is stabilized. In addition to a power supply that supplies potential to be reference potential of boosting in a DC/DC converter, a power supply for charging a capacitor in the DC/DC converter is provided. Accordingly, loads to the power supply that supplies the reference potential of boosting can be reduced. Further, as power for charging the capacitor in the DC/DC converter, power supplied from not an antenna but a secondary battery is used. More specifically, a secondary battery is used as a power supply that supplies power to a buffer circuit or an inverter circuit. Thus, power supplied from the antenna can be stabilized. In other words, operation of a logic circuit and an analog circuit can be stabilized.

Abstract: A power supply controller circuit is disclosed. An example power supply controller circuit includes a control circuit coupled to generate a switching waveform to be used to regulate an output of a power supply. A current input circuit is coupled to receive a current representative of an input of the power supply. The current input circuit is to generate a sense signal in response to the current representative of the input of the power supply. A first comparator is coupled to the current input circuit to receive the sense signal. The first comparator coupled to generate a first signal in response to the sense signal being above a first threshold. An enable/disable logic circuit is coupled to the first comparator. The enable/disable logic circuit is coupled to deactivate the control circuit in response to the first signal.

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 neutral point clamped (NPC) power converter fault protection system is provided, and include a DC bus, a switching network, and a control module. The switching network is connected to the DC bus. The switching network includes at least two leg circuits. Each of the at least two leg circuits includes at least two switches connected in series and two NPC diodes. Each of the two NPC diodes corresponds to one of the at least two switches. Each of the at least two switches has an open position. The two NPC diodes are connected between a corresponding one of the at least two leg circuits and the DC bus. The control module is in communication with the switching network. The control module includes control logic for monitoring the switching network to detect a fault condition.

Abstract: A semiconductor device includes two unit circuits and a control unit. A middle point between the unit circuits is coupled with an inductive load. Each unit circuit includes a first switching element and a free wheel diode coupled in inverse-parallel with the first switching element. At least one of the unit circuits further includes a bypass section coupled in parallel with the first switching element and the free wheel diode. The bypass section includes a second switching element and a resistor coupled in series. The controller alternately turns on the first switching elements with a dead time during which both the first switching elements are turned off. The controller controls the second switching element coupled in parallel with one of the first switching elements to be an on-state when the one of the first switching elements transitions from an off-state to an on-state in the dead time.

Abstract: Reverse recovery avoidance when converting power is provided. A first switch and second switch may be operated to supply an AC load with positive current, respective to the AC load, from a DC power source. A third and fourth switch may be operated to supply the AC load with negative current, respective to the AC load, from the DC power source. Four diodes may be employed with the switches. One diode may conduct the positive current when the first switch is off and the second switch is on. Another diode may conduct the negative current when the third switch is off and the fourth switch is on.

Abstract: An inverter control circuit (6) controls the operation of a plurality of switching elements in a three-phase inverter circuit (2) by a PWM signal. A phase voltage output from the three-phase inverter circuit (2) is outputted through a low-pass filter (3). A waveform of the phase voltage output from the low-pass filter (3) assumes the following waveforms through the control of the PWM signal. The waveform becomes zero in a first one-third period of a cycle; forms a sine wave corresponding to a phase from 0 to 2?/3 in a second one-third period; and forms a sine wave corresponding to a phase from ?/3 to ? in a remaining one-third period of the cycle. Such PWM signal cyclically includes a period where a pulse is not generated. Therefore, the switching action of the switching element is periodically stopped.

Abstract: A control system for a multilevel converter includes a differential mode current regulator, a neutral point (NP) controller and a PWM controller for generating switching pulses for the multilevel converter. The differential mode current regulator generates reference voltage command signals based on a difference between reference current command signals and actual current command signals, and the NP controller determines a modified neutral point current signal in response to a DC link voltage unbalance. The NP controller utilizes the modified neutral point current signal to generate a common mode reference voltage signal. The switching pulses are generated by the PWM controller based on the reference voltage command signals and the common mode reference voltage signal.

Abstract: A control circuit for controlling a power supply is revealed. The control circuit is used to generate a switching signal for switching the power supply. The control circuit has a detection terminal for detecting a status of the power supply. A first protection circuit is coupled to the detection terminal and to receive a first detection signal via the detection terminal, and the first protection generates a limit signal in response to the first detection signal, for limiting output of the power supply. A second protection circuit is coupled to the detection terminal and to receive a detection signal via thereto, and the second protection generates a protecting signal, for cutting off the output of the power supply, in response to the first detection signal.

Abstract: A three-phase inverter circuit includes an inverter incorporating a plurality of controllable power switches, and an electronic control device adapted to control the power switches. The control device in the event of a measured voltage drop on one phase is adapted to supply a reactive current on the phase with voltage drop and to supply and/or draw an active current on at least one phase without voltage drop.

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: A three level neutral point clamped (NPC) converter includes a plurality of phase legs each having at least two inner switching devices, at least two outer switching devices, at least two clamping diodes, and a protection circuit. An inner component failure sensing circuit is employed in the protection circuit to detect a failure condition in any of the inner switching devices or clamping diodes. The protection circuit further includes a gating signal generation circuit configured to generate a turn ON signal for a respective outer switching device that is adjacent to the failed inner switching device or the clamping diode.

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 positive pole side of the DC power supply to exhibit a conductive state and an interrupted state of a current; a second switching device connected to the negative pole side of the DC power supply to exhibit a conductive state and an interrupted state of the current; 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. Thus, conduction is provided from the second connection point to the first connection point.

Abstract: An inverter operable to interface with a generator that has a number of partial strings includes an inverter bridge circuit configured to connect to the partial strings, and a control device operably associated with the inverter bridge circuit. The inverter further includes a series-connection switching device configured to selectively connect the partial strings in series in response to a control signal from the control device such that the series-connection switching device interrupts the series connection of the partial strings in case of a hazard condition detected by the control device.

Abstract: Among many embodiments, a power conversion apparatus and a method for converting power are disclosed. The power conversion apparatus may include switching components configured to create an alternating current; a preemptive detector arranged and configured to provide, in advance of the alternating current reaching a zero-crossing, a control signal responsive to the alternating electrical current approaching the zero-crossing; and a controller configured, at least in part, to change a state of the switching components before the zero crossing, in response to the control signal.

Abstract: In a power conversion apparatus, a main switching element in one main circuit is controlled to repeat an on-off state, and a diode in the other main circuit is used as a freewheeling diode. Multiple snubber circuits each having a resistor, a capacitor, and a second switching element which are serially coupled are coupled in parallel to the main circuit. The second switching elements are turned-on sequentially before the turn-on or turn-off of the main switching element that repeats the on-off state.

Abstract: An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit is coupled to compare a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit is coupled to output a switching signal to control a switch of the power converter to regulate an output of the power converter in response the feedback circuit. The adjustable voltage reference circuit is coupled to adjust the voltage reference such that the bias winding voltage is adjusted nonlinearly in response to a load condition at the output of the power converter. The adjustable voltage reference circuit is further coupled to detect the load condition in response to the switching signal.

Abstract: A circuit for protecting a controllable power switch is provided. The controllable power switch has a first power switch terminal connected to a first terminal, a second power switch terminal connected to a second terminal, and a power switch control terminal. Further, the circuit includes a diode with a first diode terminal and a second diode terminal, and a controllable control switch having a first control switch terminal connected to the first diode terminal, a second control switch terminal, and a control switch control terminal. A signal applied to the power switch control terminal is based on a signal at the second control switch terminal. Further a method for protecting a controllable power switch is described.

Abstract: To provide an electric power conversion device that converts direct current power supplied from a direct-current power supply into alternating current power, the electric power conversion device includes six switching elements constituted by a voltage-driven transistor that uses a wide bandgap semiconductor and a diode, and a drive circuit that controls a voltage for driving the transistor at a time of turning off the switching elements based on a predetermined voltage profile specifying that the transistor is operated in a non-linear region.