Abstract: This power conversion device has: a main breaker and a main electromagnetic contactor connected to a main power supply; a converter body having a switching element; a power supply-side reactor and a device body-side reactor connected to the main electromagnetic contactor; a current detector; a smoothing capacitor; a DC voltage detector that detects a voltage of the smoothing capacitor; a control unit; and accessories. The accessories have: a power-supply phase detection transformer that detects the phase and the amplitude of a power supply voltage; a current limiting resistor that suppresses rush current to the smoothing capacitor at an initial turning-on stage of the main power supply; an electromagnetic contactor which is for turning on current limiting operation and which connects the current limiting resistor and the main power supply; and a filter circuit that removes current ripples caused by switching of the switching element.

Abstract: According to one embodiment, a power converter includes an inverter and a controller. The inverter operates in an interconnected operation mode in which a grid is connected to an electric load and an isolated operation mode in which the inverter is connected to the electric load, for generating power from a local power supply. The controller detects a frequency difference and a phase difference between an inverter output from the inverter and grid power. The controller calculates, based on the frequency difference and the phase difference, an output frequency pattern to be used for synchronizing the inverter output with the grid power. The controller controls, when switching from the isolated operation mode to the interconnected operation mode, a frequency of the inverter output based on the output frequency pattern.

Abstract: Systems and methods are described for a push-button switch assembly with the ability to diagnose faults. The push-button switch assembly comprises a first circuit comprising a first resistor arranged in series with a first switch, and a second resistor arranged in parallel with the first resistor and the first switch, and a second circuit comprising a third resistor arranged in series with a second switch, and a fourth resistor arranged in parallel with the third resistor and the second switch, wherein the first switch and the second switch are each closable by displacement of a push-button of the push-button switch assembly.

Abstract: A method for operating a multi-level bridge power converter of an electrical power system connected to a power grid includes receiving, via a controller of the power converter, an indication of a transient event occurring in the power grid or the electrical power system. The power converter has a plurality of switching devices arranged in an active neutral point clamped topology. Accordingly, upon receiving the indication, the method includes activating a crowbar algorithm programmed in the controller of the power converter to bifurcate a current received by the power converter into a plurality of different current paths defined by the plurality of switching devices.

Abstract: Pulse train conditioning circuits and related methods are disclosed. An example circuit includes a first transistor having a first current terminal and a first gate terminal, a second transistor having a second current terminal and a second gate terminal, a third transistor having a third current terminal and a third gate terminal, a fourth transistor having a fourth current terminal and a fourth gate terminal, the fourth gate terminal coupled to the first through third gate terminals, a first switch having first through third terminals, the first terminal coupled to the first current terminal, the second terminal coupled to the third current terminal, and the third terminal coupled to the fourth current terminal, and a second switch having fourth through sixth terminals, the fourth terminal coupled to the second current terminal, the fifth terminal coupled to the third current terminal, and the sixth terminal coupled to the fourth current terminal.

Abstract: A transient current in a rectifier circuit is effectively reduced. In the rectifier circuit, a current flows from a power supply to a coil when a transistor is turned ON. When the transistor is turned OFF, the current of the coil flows into a second rectifier.

Abstract: A method for controlling a three-level back-to-back voltage source power conversion assembly includes receiving an indication of a DC or AC unbalance occurring in voltage of a DC link. The power conversion assembly has a first power converter coupled to a second power converter via the DC link. In response to receiving the indication, the method includes activating a balancing algorithm that includes determining a deviation of a midpoint voltage of the DC link as a function of a total voltage of the DC link, calculating a voltage compensation needed for pulse-width modulation signals of the power conversion assembly based on the deviation, and coordinating common mode voltage injection from each of the power converters independently at a neutral point of the power conversion assembly based on the voltage compensation, thereby minimizing the at least one of the DC unbalance or the AC unbalance at any given operating condition.

Abstract: A power module for a converter, in particular for a multilevel converter. The power module includes a link circuit capacitor, two connection terminals, at least one half-bridge connected in parallel with the link circuit capacitor and having two semiconductor switches, and, for each half-bridge, a bypass diode connected in parallel with a first semiconductor switch of the half-bridge and a load-relief circuit group connected in parallel with the first semiconductor switch. The load-relief circuit group has a load-relief thyristor and a load-relief diode connected in series with the load-relief thyristor.

Abstract: An inverter circuit is connected serially with a first silicon carbide MOSFET and a second silicon carbide MOSFET. During a dead time when the first silicon carbide MOSFET and the second silicon carbide MOSFET are OFF, transient current of at least 100 A/cm2 flows in a built-in diode of the first silicon carbide MOSFET and a built-in diode of the second silicon carbide MOSFET.

Abstract: The present disclosure discloses a method of discharging a bus capacitor in a power converter, the method comprising: outputting a plurality of pulse control signals to the corresponding plurality of power semiconductor switch groups when the working state of the power converter is in a discharge state and the state of the main circuit breaker is open to control the ON and OFF of the plurality of power semiconductor switch groups, respectively, so as to form a discharge loop between the positive terminal and the negative terminal of the bus capacitor within at least a preset time, thereby causing the bus capacitor to discharge. Since a discharge loop is formed by the bus capacitor and the bridge arms and the energy of the bus capacitor is consumed by a power device, thereby the peak value and discharge rate of discharge current can be effectively controlled without adding additional discharge elements.

Abstract: A control device for controlling a power semiconductor component which includes at least two voltage-controlled power semiconductor devices which are electrically connected in parallel and which have each a control connection is disclosed. The control device includes a driver element which can be used to set electrical voltages at the control connections of the power semiconductor devices. The control device includes a measuring unit configured to capture electrical currents which flow through the power semiconductor devices. The driver element is configured to set a level and/or a temporal profile of the electrical voltages on the basis of the electrical currents.

Abstract: A semiconductor device includes a MOSFET including a PN junction diode. A unipolar device is connected in parallel to the MOSFET and has two terminals. A first wire connects the PN junction diode to one of the two terminals of the unipolar device. A second wire connects the one of the two terminals of the unipolar device to an output line, so that the output line is connected to the MOSFET and the unipolar device via the first wire and the second wire. In one embodiment the connection of the first wire to the diode is with its anode, and in another the connection is with the cathode.

Abstract: An islanding detection method and apparatus for an inverter, and a power supply system to resolve a problem that an existing voltage total harmonic distortion (THD)-based islanding detection method has low islanding detection reliability due to existence of a relatively large detection dead zone. According to this detection method, the voltage total harmonic distortion changes more significantly before and after the islanding effect of the inverter occurs in order to reduce an islanding detection dead zone and improve islanding detection reliability.

Abstract: An electronic circuit includes: a bus bar connected to a power source having a positive terminal and a negative terminal; and a plurality of object switching elements as driving objects connected to the bus bar, the object switching elements forming a parallel connected circuit. The object switching elements include minimum on-resistance elements having minimum on-resistance compared to other object switching elements in a corresponding current region among mutually different current regions; and connection points between the minimum on-resistance elements and the bus bar are located at different locations to have mutually different inductance of respective conduction paths between the power source to the connection points located at the different locations.

Abstract: There is provided a radio frequency power source device configured to change a voltage ratio between two output end voltages, by switching a connection state of a voltage divider that divides the radio frequency voltage, in such a manner that the radio frequency voltage is divided into voltage outputs in antiphase with each other with respect to ground potential, and high voltage and low voltage are delivered in switching manner. Switching of the connection state in the voltage divider enables selective delivery of voltage having different values, high voltage or low voltage, and by selecting and delivering high voltage for the time high voltage is required, reduction of the voltage output from the radio frequency output circuit is prevented.

Abstract: A solar collection system may collect energy from the sun to generate electricity for distribution on an electrical grid. In addition to generating electricity, a solar collection system may include support devices such as motors, controllers, sensors, and other support devices to perform various tasks to allow the solar collection system to more effectively generate electricity. When the solar collection system is generating sufficient power, the support devices may be powered by the solar collection system. However, when the solar collection system is not generating sufficient power, the support devices may be powered by a backfeed power supply circuit coupled to the electrical grid.

Abstract: A rotary electrical machine control apparatus is provided which controls drive of a rotary electrical machine having a plurality of winding sets. The apparatus includes inverters that are provided so as to respectively correspond to the winding sets, a temperature detection element that detects a base element that is used as a base for estimation of inverter temperatures, which are temperatures of the inverters, and a control section that has a temperature estimation section that estimates the inverter temperatures based on the base temperature and a temperature change amount generated due to current application to the inverters. On-resistance of the switching elements of the first inverter is smaller than on-resistance of the switching elements of the second inverter. The temperature detection element is disposed in an area, a distance between the area and the first inverter being shorter than a distance between the area and the second inverter.

Abstract: A simple, economically efficient, synchronized switching system for control of a three phase motor contactor utilizes only Voltage monitoring to determine zero crossings and knowledge of the sinusoidal power waveforms and operational delay period of the contactor, to synchronize operation of the contacts at low power. The phases can be serially utilized for zero crossing detection upon Close or Open commands, so as to spread the wear over each set of contacts. Expensive metal at the contact surfaces can therefore be used more efficiently. For arc energy reduction upon contact opening, knowledge of Line-Load Voltage on at least one phase can be used to derive an empirical determination of the voltage angle at opening which yields the lowest arc energy.

Abstract: A multi-phase power device for driving an inductive load includes a first semiconductor device and a second semiconductor device connected in series in each of three phase arms. Each first semiconductor device includes a first switching device made of a wide-bandgap semiconductor and a freewheeling diode that is made of a narrow-bandgap semiconductor and is connected in anti-parallel to the first switching devices. Each second semiconductor device includes a second switching devices made of a wide-bandgap semiconductor and a freewheeling diode connected in anti-parallel to the second switching device.

Abstract: A boost converter is configured of a boost chopper having a diode of an upper arm and a switching element of a lower arm. Output power from a battery to a load is limited such that a current flowing through boost converter does not exceed a current upper limit value for thermal protection of boost converter. The current upper limit value is set based not only on a cooling water temperature of boost converter but also on an output voltage VH of boost converter, in consideration of characteristics that, as output voltage VH rises, an amount of heat generated in diode decreases, diode being regarded as a main target of thermal protection since it receives a power running current to load. Thereby, the boost converter can be protected from overheating without excessively deteriorating vehicle traveling performance.

Abstract: A comparator circuit includes a first comparator, a second comparator, and a logic portion. The logic portion adjust a variable reference voltage input to the second comparator to become close to a reference voltage input to the first comparator, during a period from a time point when reverse current of current flowing in a coil disposed in a switching power supply device is detected in a state where a first comparison signal is output as a comparison signal while the first comparator and the second comparator are operated, until a first predetermined period of time elapses in a state where switching operation of the switching power supply device is stopped (excluding a period from a time point when the reverse current is detected until a second predetermined period of time shorter than the first predetermined period of time elapses).

Abstract: A semiconductor device includes a MOSFET including a PN junction diode. A unipolar device is connected in parallel to the MOSFET and has two terminals. A first wire connects the PN junction diode to one of the two terminals of the unipolar device. A second wire connects the one of the two terminals of the unipolar device to an output line, so that the output line is connected to the MOSFET and the unipolar device via the first wire and the second wire. In one embodiment the connection of the first wire to the diode is with its anode, and in another the connection is with the cathode.

Abstract: System and method for protecting a power conversion system. An example system controller includes a protection component and a driving component. The protection component is configured to receive a feedback signal, a reference signal, and a demagnetization signal generated based on at least information associated with the feedback signal, process information associated with the feedback signal, the reference signal, and the demagnetization signal, and generate a protection signal based on at least information associated with the feedback signal, the reference signal, and the demagnetization signal. The demagnetization signal is related to multiple demagnetization periods of the power conversion system, the multiple demagnetization periods including a first demagnetization period and a second demagnetization period.

Abstract: The disclosure relates to the crossing field between a power transmission of an ultra-high-voltage and a power system simulation, specifically a method for analyzing an operation state of a substation by combining a whole grid model with a local grid model is provided according to the disclosure. The method includes following steps: performing a load flow calculation for the provincial grid to which a ultra-high-voltage line belongs, wherein initial data of the load flow calculation employs a grid model with E format for national power grid dispatching control center; making an equivalent transform for the model, forming an island independently from the provincial grid to which a ultra-high-voltage line belongs, and making a load flow calculation for the island to acquire data of node voltages and line transmission power.

Abstract: A multilevel converter has a plurality of series-connected sub modules, which each have at least one first switch, one second switch and one capacitor. Current is output by way of the capacitor during discharging phases and current is received or charging the capacitor during charging phases. At least one of the sub modules has two part-modules that are galvanically connected to each other or are formed by two part-modules that are galvanically connected to each other. Each has a first switch, a second switch and a capacitor, and a first and a second part-module terminal. The galvanic connection between the two part-modules includes at least one inductive element.

Abstract: A semiconductor device includes a MOSFET including a PN junction diode. A unipolar device is connected in parallel to the MOSFET and has two terminals. A first wire connects the PN junction diode to one of the two terminals of the unipolar device. A second wire connects the one of the two terminals of the unipolar device to an output line, so that the output line is connected to the MOSFET and the unipolar device via the first wire and the second wire. In one embodiment the connection of the first wire to the diode is with its anode, and in another the connection is with the cathode.

Abstract: A mixed power supply device includes a power supply component for providing a DC voltage; a DC-DC conversion module coupled to the power supply component to receive the DC voltage and output a stable DC voltage; a current transformation module coupled between the DC-DC conversion module and a load to receive the stable DC voltage and convert the stable DC voltage into an AC voltage; and a merging network switching switch coupled to the current transformation module to connect the current transformation module and a utility power network in parallel or disconnect the current transformation module from the utility power network, allowing a load to receive merging network mode-based power supply or standalone mode-based power supply, wherein, in the merging network mode, the current transformation module performs unbalanced current compensation on load unbalance of the load.

Abstract: There is provided an inverter test apparatus for testing an inverter interconnected with an alternating-current power system, the apparatus including an alternating-current power output unit configured to output alternating-current power, and an alternating-current power controller configured to control the alternating-current power output from the alternating-current power output unit to simulate an alternating-current load of the inverter.

Abstract: The invention relates to a method for checking a separation point (14) between a photovoltaic inverter (1) and a power supply network (7) having multiple phases (L1, L2, L3) and a neutral conductor (N), wherein multiple switching contacts of the separation point (14) are controlled by the photovoltaic inverter (1), and to a photovoltaic inverter (1). To allow a simple and quick check of the functionality of the separation point (14), the switching contacts of the separation point (14) are each formed by single-pole relays (15-22) and switched in steps according to a switching pattern. For checking switching contacts, a voltage (26, 27, 28) is measured at at least one phase (L1, L2, L3) with respect to the neutral conductor (N), upstream of the separation point (14), and compared to voltage values assigned in accordance with the switching pattern, thereby to deduce the functionality of the switching contacts.

Abstract: In one aspect, this disclosure relates to a method of controlling current output from a switching regulator to a load via an inductor. Inductor current information can be sampled at a peak level, such as just before a transistor configured to cause current to flow through the inductor is turned off. The sampled inductor current can be compared with a reference current, and a current limit threshold can be adjusted based on the comparison. The output current of the switching regulator can be controlled based on a comparison of the current limit threshold with an indicator of current flowing through the inductor. This method can accurately and efficiently limit current in a switching regulator.

Abstract: A circuit having a plurality of parallel-connected partial circuits for feeding an inverter circuit. A partial circuit comprises an unregulated voltage source with a temporally variable output DC voltage and a synchronous converter having an automatically functioning regulating circuit. The circuit is triggered according to two modes of operation. The first mode of operation is as an upward converter, when the value of the output voltage of the unregulated voltage source exceeds a threshold value, and thus the inverter circuit is supplied with the requisite input voltage. The second mode of operation is as a downward converter, when the value of an output voltage of the unregulated voltage source is below a threshold value, or when there is no output voltage from the unregulated voltage source, in which case a first capacitor is charged from the DC voltage applied to the second terminals.

Abstract: An apparatus and a method for detecting phase deficiency in an inverter is provided, the method including deciding whether a sector of the output current is a sector where current detection is possible based on switching operation status of the switching element in the inverter, maintaining a phase deficiency variable when deciding the current detection in the sector of the output current to be impossible, adding a count to a phase deficiency variable to accumulate when deciding the current detection in the sector of the output current to be possible and deciding the output current to be within a phase deficiency band, and determining as phase deficiency when the phase deficiency variable is greater than a prescribed detection level.

Abstract: Provided is a configuration in which it is possible to mount an applied voltage suppression circuit configured to prevent voltage breakdown of a semiconductor switching element, and a set voltage thereof can be inspected without damaging an IC or the like of a peripheral circuit. In a power converter having a semiconductor switching element, an applied voltage suppression circuit configured to suppress a voltage applied to the semiconductor switching element and at least one component of constituent components of a driving circuit which causes the semiconductor switching element to be turned off if the component is absent are transferred to and disposed on a slave substrate (separate unit) which is divided from and electrically connected to a master substrate including the semiconductor switching element, the driving circuit, a control circuit, and the like mounted thereon.

Abstract: A processor unit in an electric power converter executes detection of an overheating predicted state that is a stage prior to overheating of the IGBTs, a short circuit predicted state that is a stage prior to a short circuit in the arms, and a voltage drop predicted state that is a stage prior to a drop in a control voltage to be supplied to a driver circuit. When none of these predicted states is detected, a determination that an abnormality is not caused in the power module based on a latch signal is made by the processor unit. When an overheating predicted state is detected, the processor unit lowers the duty ratio of a motor control signal. When a short circuit predicted state is detected, the processor unit prolongs the dead time in which the upper IGBTs and the lower IGBTs are both maintained in the off-state.

Abstract: A cascaded multi-level inverter is controlled in fault bypass operation. Rather than relying on approximations or feedback forms, the reference voltages are generated as an analytic solution. The analytic solution and its implementation are not affected by the output frequency of the inverter and it is able to provide maximum possible balanced line-line voltage to a three-phase motor. In addition, the analytic solution provides exact limits for the allowable operation region of the motor power factor in order to prevent overvoltage conditions of the cell inverter.

Abstract: An inverter device includes: an inverter circuit configured to perform ON/OFF operations with a preset duty cycle to convert a DC power into an AC power and output the AC power to an AC motor; and a controller configured to change a duty cycle of the ON/OFF operations.

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 compares a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit outputs a switching signal having a switching period to control a switch to regulate an output of the power converter in response to the feedback signal and enables or disables a switching period based on the output of the feedback circuit. The adjustable voltage reference circuit adjusts the voltage reference by a first amount in response to a first number of disabled switching periods indicating a first load condition at the output of the power converter and by a second amount in response to a second number of disabled switching periods indicating a second load condition at the output of the power converter.

Abstract: An inverter may include an inversion unit for converting a direct current bus voltage into an alternating current voltage, a first snubber unit, and a second snubber unit. The inversion unit may include a first external switch, a first internal switch, a second internal switch, and a second external switch which are connected in series in order between a direct current bus positive voltage terminal and a direct current bus negative voltage terminal. The first snubber unit may be connected between the direct current bus negative voltage terminal and the first internal switch for suppressing voltage stress of the first internal switch. The second snubber unit may be connected between the direct current bus positive voltage terminal and the second internal switch for suppressing voltage stress of the second internal switch.

Abstract: A power conversion system includes a bus bar, a switch coupled to the bus bar and configured to receive a DC input voltage from a voltage source through the bus bar, and a parallel fuse system. The parallel fuse system may be disposed on the bus bar in series with the voltage source and the switch. The parallel fuse system includes two or more parallel fuses, and may be configured for an inductance imbalance between the fuses, such that there is an asymmetric flow of currents through the fuses when the power conversion system is in operation. For the inductance imbalance, for example, the fuses may be positioned asymmetrically with regard to a shortest conductive path from the voltage source to the switch.

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: A system, method, and apparatus is disclosed for interfacing and transferring power unidirectionally or bidirectionally between a direct current (DC) line and a single or multiphase alternating-current (AC) line for only half of any given phase and only a single phase at a time when polarity is matched between the DC and the AC system. A circuit with simplified, robust, and reduced-cost components perform the power conditioning and the synchronization as a system that simulates a half-wave rectifier/inverter.

Abstract: An inverter for driving a motor generator has series connection units, each of which has two switching elements, connected in series, in high and low voltage sides, respectively. A drive unit is arranged for each switching element. A gate of the switching element is connected to an emitter thereof through a first cutoff resistance and a first cutoff switching element in the drive unit. The gate of the switching element is also connected to the emitter thereof through a second cutoff resistance and a second cutoff switching element in the drive unit. A resistance value of the first cutoff resistance is higher than a resistance value of the second cutoff resistance. A software cutoff process is performed when the switching element is in a completely turned-on state so that the first cutoff switching element is turned on and the second cutoff switching element is turned off.

Abstract: An electric vehicle includes: a main battery; an electric power converter configured to convert power to driving power of a drive motor; an auxiliary battery configured to supply power to auxiliaries; a power supply harness connecting the auxiliary battery to the auxiliaries; a step-down converter having an output end connected to the power supply harness, the step-down converter being configured to step down an output voltage of the main battery to the driving voltage of the auxiliaries; an interrupter configured to isolate the step-down converter from the power supply harness at the time when a predetermined specific abnormality has been detected; and a discharger configured to discharge a capacitor incorporated in the electric power converter, the discharger being configured to operate by receiving electric power supplied from a first power supply path which connects the output end of the step-down converter to the interrupter.

Abstract: An electric generating system using a solar cell improves the quality of output power by including a converter for converting an output voltage generated from the solar cell into DC voltage in a pulse shape. An inverter converts the DC voltage in the pulse shape into an AC voltage and applies the AC voltage to a power system and a control device for determining whether an erroneous operation of the electric generating system using the solar cell is generated or not based on an output voltage of the solar cell, an output current of the solar cell and a voltage of the power system. At least one inverter switching device among a plurality of inverter switching devices performs a switching at a frequency higher than a frequency during a normal operation at an interval where the erroneous operation is generated.

Abstract: The invention relates to a switch cabinet arrangement of a device for generating electrical energy, wherein the switch cabinet arrangement comprises at least two separate power switch cabinets. The technical object of achieving an optimum scalability of devices for generating electrical energy with at the same time a simple installation and maintenance of the power switch cabinets despite a small available installation space, is achieved according to the invention in that the power switch cabinets respectively comprise a machine connection, a power module, a mains connection and a decentralised control unit, wherein the power module comprises a machine converter, a mains converter, a direct voltage intermediate circuit and a chopper, and wherein the power switch cabinets are electrically connected in parallel to one another via the machine connection and the mains connection.

Abstract: A power conditioner according to an exemplary aspect of the present invention includes a first converter that converts a first DC voltage supplied from an external power supply into a second DC voltage, an inverter that converts the second DC voltage into an AC voltage and outputs the AC voltage to an external line so as to keep receiving power by the external line from a supply source system in a predetermined range, and an energy management unit that stops operations of the first converter and the inverter at predetermined time previously determined based on a magnitude of load power consumed by a load connected to the external line.

Abstract: Peak current in a switching converter is controlled using a closed loop to compensate for error caused by delay time in the switching transistor and control logic. A reference value is established that represents a target current value. A compensated reference value is derived from the reference value by the closed loop. A periodic inductor current is formed in the switching converter in response to the compensated reference value. An error signal is formed that is indicative of an amount of time the inductor current exceeds the target current value. The compensated reference value is dynamically adjusted by the compensation closed loop to minimize the error signal.

Abstract: Control devices can be destroyed or damaged by their supply voltage in the event of malfunction. The voltage supply according to the present invention comprises a means (12) having a primary part (121) and secondary part (122), the primary part (121) being connected to the voltage source (10) and being controllable by means of the voltage output (112) of the voltage converter (11), and the secondary part (122) comprising a first and a second mutually independent winding, a supply voltage for the control device being made available by means of the first winding, and the second winding being connected to the voltage input (111) of the voltage converter (11) so that a supply voltage, additional to the voltage source (10), for the voltage converter (11) is implemented by means of the second winding.

Abstract: A fault protection and correction circuit for the control of a power converter is disclosed. An example circuit generates a waveform that drives a switch on or off and controls the power converter. The controller circuit in addition to power factor correction (PFC) circuitry includes a first and a second shut down mode modules, both of them cause the switching to stop. The circuit includes a module for receiving fault events. When a fault occurs, the controller enters the second shut down mode. The controller stays in the second shut down mode if the required current for this mode can be provided by the outside circuitry. Otherwise, the controller enters the first shut down mode that requires less current and subsequently restarts the controller. By modifying the outside circuitry the controller can respond differently to fault events.

Abstract: A power conversion apparatus, such as an uninterruptible power supply, included first and second DC busses, a neutral node and an inductor configured to be coupled to a load. The apparatus further includes an inverter circuit coupled to the first and second DC busses, to the neutral node and to the inductor and configured to selectively couple the first and second DC busses and the neutral node to a first terminal of the inductor to generate an AC voltage at a second terminal of the inductor such that, in a given half-cycle of the AC voltage, the inverter circuit uses a switching sequence wherein the first DC bus, the second DC bus and the neutral node are successively coupled to the first terminal of the inductor.