Abstract: An electric power converter includes a DC to DC converter section adjusting DC power of a battery with at least two units in series, a DC circuit having at least two DC link capacitors in series between a positive and a negative line from the DC to DC converter section, an electric power converter section connected to the DC circuit to convert DC electric power to AC electric power for a motor, a bilateral switching circuit connecting an intermediate potential point between the capacitors and an AC output point in the electric power converter section, and a short-circuit between the intermediate potential point of the DC circuit and an intermediate potential point between the battery units. Normal operation of a load is ensured even when the battery, the capacitor in the DC circuit or the switching device in the electric power converter section becomes abnormal, while achieving high efficiency.

Abstract: A power supply system includes an electromagnetic interference (EMI) filter circuit, a rectifier and filter circuit, a switch circuit, a transformer, a feedback circuit and a controller. The feedback circuit includes a voltage divider circuit, a filter circuit, and a voltage and temperature compensation circuit. The voltage divider circuit generates a voltage dividing signal, and includes a first lossless element and a second lossless element connected in series between an output of the transformer and the ground, and the voltage dividing signal is generated at a node of the first and second lossless elements. The filter circuit filters the voltage dividing signal into a direct current (DC) signal. The voltage and temperature compensation circuit does voltage compensation and temperature compensation to the DC signal to generate a feedback signal, and sends the feedback signal to the controller.

Abstract: A power conversion system eliminates output transformers and replaces them with a zig-zag transformer and a filter that provides a 3-phase 5-wire system with significantly reduced weight and size as compared with conventional systems. The zig-zag transformer may have a low zero sequence impedance. The power conversion system also ensures operational safety by detecting various types of ground faults.

Abstract: The performance of a power transducer is improved while efficiently using a power semiconductor also by managing the permissible duty factor of the power semiconductor in the regenerative braking circuit provided in the power transducer. The user is allowed to set, through an operation panel provided on the power transducer, the resistance value of the regenerative braking resistor for thermally consuming the rotational energy generated during motor deceleration. The power transducer performs the steps of: calculating the current which flows in the regenerative braking circuit from the resistance value setting; obtaining the generation loss of the power semiconductor in the regenerative braking circuit with the calculated current value; and determining the permissible duty factor of the power semiconductor from the obtained generation loss.

Abstract: A method for operating a circuit arrangement is provided. The method may include coupling a second connection of a control device to a connection that provides an alternating signal during operation of the circuit arrangement; in the control device: generating a trigger signal for the control electrode of the mode switch that is correlated with the sum signal from the signal at the connection for providing an alternating signal and the control signal; and providing the trigger signal at the output of the control device.

Abstract: A power conversion system includes a power transformer for receiving AC power at a first voltage from an input side and for delivering AC power at a second voltage to an output side. A power converter is also included in the power conversion system wherein the power converter includes an input side converter on the input side and an output side converter on the output side coupled through a plurality of DC links. A converter controller in the power converter provides control signals to the input side converter and the output side converter for regulating an active power and a reactive power flow through the power converter. Each of the input side converters and the output side converters includes at least two power converter transformers coupled between respective power converter bridges coupled to the plurality of DC links and the input side or to the plurality of DC links and the output side.

Abstract: A power converter includes at least two power conversion sections operating in parallel. The power converter receives a variable input power and generates an AC output voltage. When the power source is generating enough power to supply a DC voltage to the power converter greater than or equal to the peak magnitude of the desired AC voltage output, each power conversion section operates in parallel, converting the DC voltage to the desired AC voltage output. When the power generated by the variable power source results in a DC voltage having a magnitude less than the peak magnitude of the desired AC voltage output, the power conversion sections operate in series. One power conversion section operates as a boost converter to boost the DC voltage level to a suitable level for the second power conversion section, which generates the desired AC output voltage.

Abstract: A control section controls a current-source converter while a switch is conducting, to render conducting a pair of a high-aim side transistor and a low-arm side transistor (for example, transistors) which are connected to any one of input lines, performs voltage doubler rectification on a voltage between a neutral phase input line on which a resistor is provided and any one of the input lines, to serve for charging of clamp capacitors.

Abstract: A system for providing, from a direct current (DC) voltage source, an alternating current (AC) to an electrical grid outputting a grid voltage, the system including: a transformer for coupling to the DC voltage source through a first switch controlled by a first control signal, and configured to provide a converted voltage based on a DC voltage; a rectifier coupled to the transformer, and configured to generate an envelope voltage of the converted voltage; a plurality of switches coupled to the rectifier to receive the generated envelope voltage of the converted voltage, the plurality of switches being controlled by a plurality of control signals, respectively, and configured to generate the AC from the generated envelope voltage of the converted voltage; and control apparatus coupled to the first switch and the plurality of switches, and configured to provide, based on the grid voltage, the first control signal and the plurality of control signals.

Abstract: A DC motor is provided. The DC motor prevents rush or overload of current in the DC motor during and/or after power input irregularities to the DC motor. A control circuit of the DC motor is configured to control current provided to the DC motor. When power irregularities in the power input to the DC motor are detected by the control circuit, the control circuit stops generating PWM (Pulse Width Modulated) signals and stops the current provided to the DC motor. After the stoppage of PWM signals, the control circuit can perform a soft-start of the PWM signals when the power irregularities are no longer detected. The soft starting of the PWM signals generates gradual increase in current to the DC motor, thus, preventing sudden rush of current that cause malfunction of the DC motor.

Abstract: The invention relates to a method for inputting power into a multiphase alternating current grid by means of a transformer which is electrically interconnected between the alternating current grid and a number of input phases corresponding to the number of grid phases of the grid, wherein at least one voltage characteristic of one of the grid phases is determined, and an input of reactive currents occurs as a function of a previously determined deviation of the voltage characteristic of the at least one grid phase relative to a corresponding target voltage characteristic. It is provided that the deviation of each one of the voltage characteristics is determined, and the input of the reactive currents in case of deviations that are asymmetrical with respect to the symmetry of the target voltage characteristics is an asymmetrical input of the reactive current with respect to the respective input at the input phases.

Abstract: A method for controlling a frequency converter is provided. The converter includes a rectifier, an inverter which is connected via a DC link to the rectifier, a rectifier controller and an inverter controller. A minimal rectifier DC link voltage for the rectifier controller is determined, a minimal inverter DC link voltage for the inverter controller is determined, a minimal DC link voltage as the maximum of the minimal rectifier DC link voltage and the minimal inverter DC link voltage is determined, and an optimal DC link voltage reference based on the minimum of the minimal DC link voltage and a maximal allowed DC link voltage is determined. The rectifier controller and/or the inverter controller is/are controlled based upon the optimal DC link voltage reference.

Abstract: A device, system, and method for global maximum power point tracking comprises monitoring an output power of a DC power source while executing a maximum power point tracking algorithm and adjusting a maximum power point tracking command signal in response to the output power being less than a reference output power. The command signal is adjusted until the output power exceeds a previous output power by a reference amount. The command signal may be a voltage command signal, a current command signal, an impedance command signal, a duty ratio command signal, or the like.

Abstract: A power conversion apparatus includes a main circuit with switches, and performs power conversion to generate power to a three-phase AC load from a three- or single-phase AC power supply. Some of the switches are configured, using a bidirectional switch including a normally-on device that is turned OFF when a gate circuit is provided with a positive or negative voltage, and a normally-off device that is turned ON when the gate circuit is provided with a positive or negative voltage, to provide only a specific unidirectional current flow when the gate circuit is not activated, and when the gate circuit is activated, provide and control a bidirectional current flow to direct only in an arbitrary unidirectional way. By providing the power conversion apparatus with a capability of directing back, to a load (motor), any power coming therefrom, the conversion apparatus requires no direct-current link capacitor and a diode clamping circuit.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: Embodiments of the present invention provide novel techniques for using multiple 18-pulse rectifier circuits in parallel. In particular, each rectifier circuit may include an autotransformer having 15 inductors coupled in series, joined by 15 nodes interposed between pairs of the inductors. The inductors may be represented as a hexagon in which alternating sides of the hexagon have two and three inductors, respectively. Each rectifier circuit may also include three inputs for three-phase AC power coupled to alternating vertices of the hexagonal representation and nine outputs for AC power coupled between each node that is not a vertex of the hexagonal representation and a respective diode bridge. Outputs of the diode bridges for the rectifier circuits may be coupled to a DC bus. In addition, a means for reducing circulating current between the parallel rectifier circuits and for promoting load sharing between the parallel rectifier circuits is also provided.

Abstract: A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system receives input of an initial voltage-frequency command to the AC motor drive, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and determines a real-time value of a motor parameter based on the real-time output of the AC motor drive. The control system also inputs a plurality of modified voltage-frequency commands to the AC motor drive, determines the real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and identifies an optimal value of the motor parameter based on the real-time values of the motor parameter.

Abstract: A projection system incorporating a prism with dual total internal reflection function, to increase the performance of DLP™ projection, by offering a solution to combine 2 light paths to contribute to the brightness on the screen and at the same time rejecting flat-state and off-state light from entering the projection lens thereby enhancing contrast. In one implementation those two light paths can be collecting light from 2 different light sources which are driven in a pulsed manner with a duty cycle of approximately 50% for each of the two light sources at increased power. In a second implementation with a color sequential single DMD™ projector, while one light path passes a primary color the second light path passes the complementary secondary color. A special color transformation algorithm is proposed to transform the image input signals to make optimal use of the capabilities offered by the second implementation, and create maximum brightness and color saturation of the image.

Abstract: A power supply system with an electronic high-voltage transformer includes an input module for receiving a current and eliminating disturbance in the current, a transformer module for transforming the received current into a low-voltage direct current, a power supply module for transforming the low-voltage direct current into a high-frequency alternating current, and a magnetic processing module comprising one or more magnetic elements and one or more high-voltage resistant wires connecting with the magnetic elements so as to transform the high-frequency alternating current into a high-voltage alternating current.

Abstract: A universal power supply for use in a plasma arc system is disclosed. The power supply can include a plurality of power modules for providing a DC output from an AC input. Each of the power modules can include a rectifier, a converter, an inverter, an isolation transformer and an output rectifier. The power modules can include a power module controller configured to control at least one of the rectifier, the converter, or the inverter such that a DC output can be obtained from a wide variety of AC inputs. The power modules can be connected in parallel to provide a wide range of DC output currents for the power supply. The universal power supply can include a master controller coupled to each of the individual power module controllers to regulate the DC output current of the power supply by controlling the individual power module controllers.

Abstract: A control section controls a current-source converter simultaneously with or prior to conduction of a power supply switch to connect a clamp capacitor and capacitors between a first input line on which a resistor is provided and any one of second and third input lines in parallel with each other. Accordingly, current is transmitted to the clamp capacitor via the resistor when the power supply switch is brought into conduction, which prevents inrush current from flowing to the clamp capacitor. In addition, for example, the capacitors are not charged prior to the clamp capacitor, whereby it is possible to prevent the inrush current from flowing from the capacitors to the clamp capacitor when they are connected in parallel with each other.

Abstract: There is provided a method of customizing an audio presentation for tailoring to a predetermined event sequence, one embodiment comprising identifying the predetermined event sequence from a predetermined event sequence database, associating a first audio asset with one or more selected events of the predetermined event sequence, synchronizing the timing of the first audio assets with the timing of the selected events, and linking the first audio assets to produce a customized audio presentation tailored to the predetermined event sequence. In one embodiment, the method includes downloading an interactive audio presentation content including an interactive audio presentation program, an audio assets database, and the predetermined event sequence database to a client computer. In one embodiment, a system for customizing an audio presentation tailored to a predetermined event sequence comprises a client computer, a client memory located on the client computer, and interactive audio presentation content.

Abstract: The maximum electrical power drawn from an electrical power source by a mining excavator comprising electric motors is reduced by supplying supplementary electrical power from an electrical energy storage unit. The input electrical power drawn by the mining excavator is cyclic. An upper limit is set for the electrical power drawn from the electrical power source. When the input electrical power drawn by the mining excavator exceeds the upper limit, electrical power is supplied by the electrical energy storage unit, such as an ultracapacitor bank. The ultracapacitor bank may be charged by the electrical power source during off-peak intervals. Electrical power generated by electrical motors operating in a regeneration interval may also be recaptured and stored in the electrical energy storage unit.

Abstract: There is provided a high frequency power supply device. The power control unit comprises an impedance adjuster that includes a variable reactance element and adjusts a load side impedance by changing a reactance value of the variable reactance element, and an impedance control unit that controls the variable reactance element of the impedance adjuster in response to a power value detected by a power detection unit so as to perform control of approximating the power value of the high frequency power, which is fed from the high frequency power generation unit to the load, to the setting value or control of maintaining the power value within the set allowable range by changing a resistance of the load side impedance in response to the power value detected by the power detection unit.

Abstract: A control section controls a current-source converter in a state in which a switch is in conduction, and performs voltage doubler rectification on a voltage between a neutral phase input line and any of input lines to provide for charging of clamp capacitors. Accordingly, the clamp capacitors are charged through a resistor, which prevents an inrush current from flowing therethrough. In addition, a voltage between both ends of a pair of the clamp capacitors is higher than, for example, a voltage between both ends of a pair of capacitors. Accordingly, even if the clamp capacitors and, for example, the capacitors are electrically connected to each other in a normal operation, it is possible to prevent the inrush current from flowing from the capacitors to the clamp capacitors.

Abstract: An apparatus and method for driving a motor of an air conditioner are disclosed. A method for driving a motor of an air conditioner includes driving the motor in response to a predetermined speed command, sequentially detecting first and second mechanical angles in response to the speed command or a reference speed being spaced apart from the speed command by a predetermined range, calculating a maximum speed mechanical angle corresponding to a maximum speed ripple of the motor on the basis of the detected first and second mechanical angles, and compensating for load torque of the motor on the basis of the calculated the maximum speed mechanical angle. As a result, the speed ripple is decreased during the constant speed operation.

Abstract: A control apparatus for an AC motor controls an inverter in a pulse width modulation scheme to feed a coil current to a stator coil of a stator. A pattern switching mechanism switches a control pattern to a first pattern or to a second pattern; a first pattern calculating mechanism calculates a control signal using a first pattern parameter; a second pattern calculating mechanism calculates a control signal using a second pattern parameter; an offset calculating mechanism calculates a difference between a control signal of an old pattern and a control signal of a new pattern, and reflects the offset amount on the control signals; and a control output mechanism calculates a final control output signal on the basis of the control signals, and transmits the final control output signal to the inverter.

Abstract: Techniques for using multiple 18-pulse rectifier circuits in parallel are described herein. In particular, each rectifier circuit may include an autotransformer having 15 inductors coupled in series, joined by 15 nodes interposed between pairs of the inductors. The inductors may be represented as a hexagon in which alternating sides of the hexagon have two and three inductors, respectively. Each rectifier circuit may also include three inputs for three-phase AC power coupled to alternating vertices of the hexagonal representation and nine outputs for AC power coupled between each node that is not a vertex of the hexagonal representation and a respective diode bridge. Outputs of the diode bridges for the rectifier circuits may be coupled to a DC bus. In addition, a means for reducing circulating current between the parallel rectifier circuits and for promoting load sharing between the parallel rectifier circuits is also provided.

Abstract: Method and arrangement for connecting an AC electric motor (M1, M2, . . . MN) to an AC electricity network (L) in a system which comprises a frequency converter (FC), with which the motor is started, and contactors (S11, S12, S21, S22, SN1, SN2), in which method the supply source is changed by means of the contactors from the frequency converter to a direct network supply, in which method the frequency converter is stopped before changing the supply source, and in which method in connection with changing the supply source the control of the contactors is started before stopping the frequency converter.

Abstract: A DC motor is provided. The DC motor prevents rush or overload of current in the DC motor during and/or after power input irregularities to the DC motor. A control circuit of the DC motor is configured to control current provided to the DC motor. When power irregularities in the power input to the DC motor are detected by the control circuit, the control circuit stops generating PWM (Pulse Width Modulated) signals and stops the current provided to the DC motor. After the stoppage of PWM signals, the control circuit can perform a soft-start of the PWM signals when the power irregularities are no longer detected. The soft starting of the PWM signals generates gradual increase in current to the DC motor, thus, preventing sudden rush of current that cause malfunction of the DC motor.

Abstract: A transformer module includes a main primary winding coupled to a first input power source to receive a medium voltage signal, multiple main secondary windings each to couple to a power cell of a drive system, and an auxiliary primary winding coupled to a second input power source to receive a low voltage signal. The auxiliary primary winding can be spatially separated from the main windings to increase leakage inductance. The auxiliary primary winding can be active during a pre-charge operation to pre-charge the power cells.

Abstract: A method of controlling a plurality of power converters 1a, 1b and 1c can be used to interface to a supply network, ac busbar etc. Each power converter includes a network bridge 14 operating in accordance with a pulse width modulation (PWM) strategy having the same switching period and which causes at least one unwanted harmonic in the supply network voltage. The method includes the step of providing the switching period of the PWM strategy of each network bridge with a different time offset relative to a time datum such that the at least one unwanted harmonic in the supply network voltage is at least partially cancelled. Two alternative ways of providing the time offset are described.

Abstract: The present disclosure is related to a power control apparatus and a method for controlling power, more specifically to a power control apparatus that controls the risk of overcurrent in a power generator when the voltage in the power grid is low. In accordance with an embodiment of the present disclosure, a power control apparatus that controls power in a power generation system including a generator generating power can include a current comparator, which calculates an error current by using a difference between a current measured at the generator and a rated current of the generator, a controlling unit, which calculates a real power value by receiving the error current and outputs a switch driving signal corresponding to the calculated real power value, a switch, which is operated by the switch driving signal, and a resistance device, which is coupled to the switch to consume the error current.

Abstract: A wind turbine generator comprising: an electrical generator configured to generate AC signals, a plurality of power converters operated by a gating signal, each power converter configured to convert the AC signals from electrical generator into fixed frequency AC signals, a transducer configured to measure the combined output from the power converters, and a controller configured to phase-displace the gating signal of one of the power converters to substantially minimise harmonic components of the combined output.

Abstract: The present invention relates to an electric power supply system comprising at least two power modules coupled in parallel and comprising a first power module comprising a first control means adapted to control the operation of at least the first power module, and a second power module comprising a second control means adapted to control the operation of at least the second power module and wherein the power modules are configured to operate in a manner coordinated with other power modules, the operation of each power module including switching the power module on and/or off if demand so requires. The present invention further relates to a method for carrying out the present invention.

Abstract: Method for controlling a load with a predominantly inductive character, whereby in order to feed a phase of the above-mentioned load (3), use is made of at least two connected output voltages, derived from one or several power electronic inverters (11,12;34,35,36), with a given period for switching, modulation or sampling, characterized in that the waveforms of the output voltages concerned are different or have been shifted in time, and in that they are supplied to the load (3) via a differential-mode device (6), whereby during every complete above-mentioned period, at least one of the above-mentioned output voltages is maintained constant and thus is not connected.

Abstract: An electric energy exchange system between at least one motor-generator system and at least one storage member determining a continuous storage voltage between two branches of a bus circuit on which are connected in parallel a DC/DC converter, a filtering capacity, and a DC/AC converter connected on at least one motor-generator system. The system includes at least one thyristor connected as a bypass on the positive bus between the storage member and the output of the converter-voltage raiser to short-cut the converter, and a thyristor priming device to, based on the required voltage at the filtering capacity, determine at least in discharge the shorting of the converter-voltage raiser with direct passage of the current through the thyristor as long as the voltage of the filtering capacity, which is substantially equal to the storage member voltage, is sufficient for the electric machines to provide requested torque.

Abstract: A power converter including a rectifier stage connected to plural phases of a network delivering an input current at a determined fundamental frequency, a DC power supply bus and a bus capacitor connected to the DC power supply bus. The converter includes a controlled current source situated on the DC power supply bus, the current source making it possible to control a rectifier current, flowing on the DC power supply bus, and a controller for the controlled current source to control a rectifier current, flowing on the DC power supply bus. The controller is configured to implement a regulation loop into which are injected a first harmonic and a second harmonic synchronized respectively at six times and twelve times the fundamental frequency of the input current delivered by the network, the amplitude and phase of these harmonics being determined to limit the THDi and the PWHD.

Abstract: An AC machine control system for an AC machine (motor, generator, transformer, etc.) having open-ended windings, the control system comprising a drive circuit configured to transfer AC power between a first set of voltages and each end of the open-ended windings without the use of a substantial energy storage device, while eliminating common mode voltage and/or injecting zero sequence voltages.

Abstract: An AC/DC intermediate-circuit converter has a very wide AC input voltage range with a ZVS three-level DC/DC resonant converter with an LLC series-resonant circuit. Two intermediate-circuit capacitors are connected in series between DC intermediate-circuit connections with their common connection point forming a DC intermediate-circuit center connection (5). The DC intermediate-circuit connections are connected to the DC connections of a rectifier whose AC input connections have an AC input voltage applied thereto. A range changeover switch is arranged between an AC input connection and the DC intermediate-circuit center connection. The range changeover switch is closed in a lower AC input voltage range, when the ZVS three-level DC/DC resonant converter is operated on the basis of a “two-level operating mode” modulation strategy, such that the LLC series-resonant circuit has the full DC input voltage present between the DC intermediate-circuit connections applied to it.

Abstract: Systems and methods are described herein for managing the operations of a microgrid module. The microgrid module includes transformers and/or power converters necessary for modifying the input AC or DC power sources to meet the required characteristics of the output power. The microgrid module further comprises a power management software module and a control software module installed on a microgrid computer. The power management software module receives business parameters such as prices from power contracts. The power management software module uses the parameters to create rules for applying to the operation of the microgrid module. The rules the power management software module creates are stored locally at the microgrid computer so that they can be quickly accessed by a control software module. The control software module uses the rules in combination with data collected from sensors installed in the physical circuitry layer of the microgrid module to control the operations of the microgrid module.

Abstract: An inductive coupled power transmission circuit has a rotating transformer, including an AC voltage supply for feeding an AC voltage via a series capacitor into the primary winding of said rotating transformer and a load being coupled to the secondary winding of said rotating transformer. The AC voltage supply includes a line rectifier for receiving AC voltage from a power line and generating a DC voltage. This is fed into a DC/DC converter for converting the DC voltage from the line rectifier into a controlled intermediate DC voltage. An AC generator generates an AC voltage from the intermediate DC voltage and feeds this via a matching transformer into the primary winding of the rotating transformer. A measuring circuit measures voltages and/or currents within the AC voltage supply and a function generator estimates voltage and/or current values at the load based on the measured values and controls the DC/DC converter and/or the AC generator based on the estimated values.

Abstract: An example power delivery network includes an energy transfer element, a main power port, and a main port interface. The energy transfer element includes multiple windings, where a first power converter transfers power between a first power port and a first winding, and a second power converter transfers power between a second winding and a second power port. The main port interface is coupled cyclically reverse a dc voltage received at the main power port and provides a cyclically reversed voltage to a third winding of the energy transfer element at a fixed duty ratio, where the transfer of power between the first power port and the first winding is independent of the transfer of power between the second winding and the second power port. Also, the main power port has an effective impedance less than an effective impedance of the first power port and the second power port.

Abstract: An uninterruptible power supply system includes a plurality of uninterruptible power supply devices (U1 to U3) connected in parallel between a commercial AC power supply (70) and a load (71); and a control unit (5) selecting the required number of uninterruptible power supply devices for driving the load (71) from the plurality of uninterruptible power supply devices (U1 to U3), to cause each selected uninterruptible power supply device to be operated and to cause each remaining uninterruptible power supply device to be stopped. This control unit (5) changes the uninterruptible power supply devices to be operated from one to another in a predetermined cycle such that the plurality of uninterruptible power supply devices (U1 to U3) are identical in operation time to one another. Accordingly, the continuous operation time of each of the uninterruptible power supply devices can be shortened, so that failures occurring in each uninterruptible power supply device can be reduced.

Abstract: An inverter apparatus converts a DC power of a capacitor charged via a rectifier circuit connected to a first AC power system into an AC power, and supplies the AC power to a second AC power system. The inverter apparatus includes a discharge circuit, a control circuit, a trigger circuit, a first voltage-sag detection circuit, a control power circuit, and a second voltage-sag detection circuit. When the second voltage-sag detection circuit detects a voltage sag of the control power circuit below a threshold, the trigger circuit generates a discharge command signal for causing the discharge circuit to discharge a charge from the capacitor.

Abstract: Power conversion systems with active front end converters for example motor drives and power generation systems for distributed energy sources are presented with adaptive harmonic minimization for grid-tie converters for minimized or reduced total harmonic distortion in the line current spectrum including the source harmonic current and the grid-tie converter injected current spectrum referred to the line side.

Abstract: A method of controlling an uninterruptible power supply apparatus (UPS) is provided. The UPS apparatus includes at least an AC input voltage, a DC input voltage and a single-phase AC/AC converter. The single-phase AC/AC converter includes an AC inductor, a bus capacitor, a boost arm, a common arm and a buck arm. The method includes steps of: controlling the bus voltage to have a DC component and full-wave rectifying component, and setting a bus voltage parameter K so that the bus voltage approaches to a full-wave rectifying voltage when K approaches to 1, wherein 0?K?1.

Abstract: A control device for a vehicle, the control device including, in a housing that is installed under a floor of the vehicle: a power converter configured of a semiconductor switching circuit; a control unit that controls the output of the power converter so as to supply a required load to a power; a wiring that is connected to the power converter; a voltage detector that detects a voltage applied to the wiring and outputs the detected voltage to the control unit; and a shielding unit that shields radiation noise from the wiring to the voltage detector, wherein the control unit is disposed on a first side of the housing along a traveling direction of the vehicle, the power converter is disposed on a second side of the housing along the traveling direction of the vehicle and the voltage detector is disposed between the power converter and the control unit.

Abstract: The present invention relates to a circuit minimizing standby power in a power adapter with a power-frequency transformer (T1), which includes a sensing circuitry (1), a driving circuitry (2), a switching circuitry (3) and a resistive element (Z). When the sensing circuitry (1) senses a power supply signal of the power-frequency transformer (T1) in work mode, the switching circuitry (3) shorts the resistive element (Z); and when the power-frequency transformer (T1) is in standby mode, the electronic switch (3) is switched off and the resistive element (Z) is coupled to the power-frequency transformer (T1). The circuit attached to the power adapter reduces the standby power consumption very much, and achieves energy-saving effect with low cost.

Abstract: The performance of a power transducer is improved while efficiently using a power semiconductor also by managing the permissible duty factor of the power semiconductor in the regenerative braking circuit provided in the power transducer. The user is allowed to set, through an operation panel provided on the power transducer, the resistance value of the regenerative braking resistor for thermally consuming the rotational energy generated during motor deceleration. The power transducer performs the steps of: calculating the current which flows in the regenerative braking circuit from the resistance value setting; obtaining the generation loss of the power semiconductor in the regenerative braking circuit with the calculated current value; and determining the permissible duty factor of the power semiconductor from the obtained generation loss.