Abstract: A motor drive device is provided which includes: a first drive unit configured to drive a plurality of first motor phases; a second drive unit configured to drive a plurality of second motor phases; a common sensor configured to detect a total current flowing through a phase pair obtained by selecting one phase from the plurality of first motor phases and one phase from the plurality of second motor phases; at least one first motor phase sensor and at least one second motor phase sensor configured to detect each current flowing through each phase not included in the phase pair among the plurality of first motor phases and the plurality of second motor phases, respectively; and a drive control unit configured to control drive amounts of the first drive unit and the second drive unit for the plurality of first motor phases and the plurality of second motor phases.

Abstract: A motorized window treatment may provide a low-cost solution for controlling the amount of daylight entering a space through a window. The window treatment may include a covering material (e.g., a cellular shade fabric or a roller shade fabric), a drive assembly for raising and lowering the covering material, and a motor drive unit including a motor configured to drive the drive assembly to raise and lower the covering material. The motorized window treatment may comprise one or more battery packs configured to receive batteries for powering the motor drive unit. The batteries may be located out of view of a user of the motorized window treatment (e.g., in a headrail or in a battery compartment). The motorized window treatment may use various power-saving methods to lengthen the lifetime of the batteries, e.g., to reduce the motor speed to conserve additional battery power and extend the lifetime of the batteries.

Abstract: A manual switching type drive device is provided which comprises an outer tube, and a speed reducer, a motor core, an electrical control board, a power source and a travel unit are provided in the outer tube; the electrical control board is fixed through a fixing bracket inside the outer tube; the electrical control board is provided with a voltage sensor for controlling the stop and start of the drive device; the electrical control board is further provided with a trigger switch; the fixing bracket is provided with a slide piece which can be abutted against or separated from the trigger switch; the slide piece is connected with an actuator capable of driving the slide piece to abut against or separate from the trigger switch; an end of the actuator penetrates through the travel unit and naturally drops down for hand pull for a more convenient operating.

Abstract: According an embodiment, a work support device includes an arm unit, a brake unit, a state determination unit, and a brake control unit. The arm unit includes a grasping part configured to grasp an object, a plurality of joint parts, and a plurality of link parts actuatably coupled through each joint part. The brake unit is provided to at least one of the joint parts to restrict actuation of the arm unit. The state determination unit determines the state of the arm unit. The brake control unit controls the brake unit to restrict actuation of the arm unit in accordance with the state of the arm unit.

Abstract: A lift device includes a base including at least two rotatable wheels, a retractable lift assembly, and a coupler. The retractable lift assembly includes a first end coupled to the base and a second end that is movable relative to the base. The coupler is attached to the retractable lift assembly a distance from the first end and is configured to detachably couple the retractable lift assembly to an electro-mechanical device. The coupler includes a first flange, a second flange, a pair of diametrically opposed mounting studs, and a pin. Each one of the pair of mounting studs extends from a respective one of the first flange and the second flange. The pin extends through at least one of the first flange or the second flange below the pair of mounting studs.

Abstract: A motor control system for selectively controlling power from a power source to a load includes a PCB structure and a power converter affixed to the PCB structure that is operable to provide a controlled output power to the load. The motor control system also includes a standalone protection and control module mounted onto the at least one PCB structure so as to be electrically coupled therewith, the standalone protection and control module further including a front-end switching unit comprising a plurality of switching devices operable to selectively interrupt and control power flow from the power source to the power converter and to a bypass path that bypasses the power converter and a back-end switching unit positioned downstream from the front-end switching unit and comprising a plurality of switching devices operable to selectively interrupt power flow from the power converter and the bypass path to the load.

Abstract: A vehicle includes an electric machine with two sets of galvanically isolated windings, first and second inverters, a switching arrangement, and a controller. During charge, the controller operates the switching arrangement to isolate the first inverter from the electric machine to permit charge current to flow through one of the sets and induce a voltage in the other of the sets. During propulsion, the controller operates the switching arrangement to couple the first inverter with the one of the sets such that the first and second inverters are configured to only power one of the sets.

Abstract: A control unit calculates a motor voltage vector including a corresponding excitation voltage command and a torque voltage command in response to an output request for a motor and distributes the motor voltage vector to a first inverter voltage vector and a second inverter voltage vector while maintaining the motor voltage vector obtained to control modes of operation (PWM, overmodulation, and square wave mode) of a first inverter or a second inverter. The first inverter voltage vector includes an excitation voltage command and a torque voltage command associated with an output from the first inverter, and the second inverter voltage vector includes an excitation voltage command and a torque voltage command associated with an output from the second inverter.

Abstract: An electric motor driving system controls driving of an electric motor having windings of two or more phases each having open ends by using a pair of inverters. A control unit includes a first inverter control circuit that generates a first voltage instruction output to the first inverter based on a torque instruction and a second inverter control circuit that generates a second voltage instruction output to the second inverter based on the torque instruction. At least one of the inverter control circuits includes an electric power controller that controls allocation of electrical power supplied from a pair of power supplies to the pair of inverters, respectively, by either advancing or delaying an angle of a phase of each of vectors of voltage instructions in accordance with the target electric power instruction during execution of torque feedback control.

Abstract: Systems and methods, for controlling an output torque of a permanent magnet direct current (PMDC) machine includes a PMDC motor that includes a plurality of winding sets and a controller. The PMDC motor is configured to generate the output torque. The controller is configured to: determine, for a first winding set of the PMDC motor, a first voltage command based on a first input torque command signal and a back-EMF drop voltage of the first winding set; determine, for a second winding set of the PMDC motor, a second voltage command based on a second input torque command signal; and selectively control the PMDC motor according to the first voltage command and the second voltage command.

Abstract: A control unit distributes a motor voltage vector corresponding to an output request for a motor to a first and a second inverter voltage vectors associated with outputs from a first inverter and a second inverter, and determines whether a switching condition for three-phase-on mode is satisfied. Determining that the switching condition is satisfied, the control unit switches to three-phase-on mode in which every high-side switching element or every low-side switching element of one inverter is turned on and one end of a coil in each phase of the motor is brought into common connection, and the control unit drives the motor with an output from the other inverter. Herein, the switching condition for three-phase-on mode includes failure of one inverter and an inverter voltage vector of an output from one inverter being approximate to 0 when neither of the inverters fails.

Abstract: A driving system includes a first alternating-current rotary electrical machine and a second alternating-current rotary electrical machine. The driving system includes: a first inverter electrically connected to the first alternating-current rotary electrical machine; a second inverter electrically connected to a first end of each of phase windings constituting the second alternating-current rotary electrical machine; a step-up converter; and a third inverter that is electrically connected to a second end of each of the phase windings and transfers power to a second direct-current power source different from the first direct-current power source to drive the second alternating-current rotary electrical machine. The step-up converter raises an output voltage of the first direct-current power source and outputs the output voltage to the first inverter and the second inverter.

Abstract: A motor drive and method of controlling a motor are provided. The motor drive includes a controller generating a motor reference voltage; a DC bus providing a DC voltage having a ripple; an inverter including power switches operable to convert the DC voltage into an AC motor voltage by modulating the power switches during a plurality of switching cycles, the AC motor voltage based on the motor reference voltage; a capacitor circuit coupled to the DC bus and having a maximum capacitance that is less than 10 microfarads per ampere of a rated current; and voltage prediction logic structured to: detect a voltage value corresponding of the ripple during each of the plurality of switching cycles; and modify the motor reference voltage during each of the plurality of switching cycles using the voltage value.

Abstract: A motor control device includes an inverter configured by a plurality of arms, a smoothing unit supplying a direct-current voltage to the inverter, a shunt resistor inserted between a lower-arm switching element for each phase of the inverter and a negative-electrode side of the smoothing unit, a master motor current sensor outputting a voltage according to a current flowing in a first motor connected in parallel to the inverter, and a computing unit generating driving signals for a plurality of switching elements based on an output of the master motor current sensor and an output corresponding to a voltage drop on the shunt resistor.

Abstract: Provided is a semiconductor device including: a semiconductor element including a first electrode, a second electrode, and a gate electrode; a surge voltage measuring unit electrically connected to the first electrode or the second electrode and configured to measure a surge voltage; a variable resistor electrically connected to the gate electrode; a comparator configured to compare a surge voltage measurement value, which is acquired by measuring the surge voltage generated by a first pulse applied to the gate electrode by the surge voltage measuring unit, with a surge voltage target value; a determination unit configured to determine a setting value of a resistance value of the variable resistor based on the comparison result by the comparator; and an instruction unit configured to instruct the setting value to the variable resistor.

Abstract: According to one aspect, embodiments of the invention provide a UPS comprising a plurality of inputs, a PFC converter configured to convert 3-phase input power into DC power, an inverter coupled to a positive DC bus and a negative DC bus and configured to convert the DC power received from the positive DC bus and the negative DC bus into output AC power, a first output configured to provide a first portion of the output AC power from the inverter to a load, a second output configured to provide a second portion of the output AC power from the inverter to the load, a third output configured to be selectively coupled to a neutral line via the inverter, and a controller configured to operate the inverter to generate current between the load and the neutral line via the third output and the inverter.

Abstract: A positioning drive has a first stepper drive unit having a first stepper drive controller and a first stepper motor, and a second stepper drive unit having a second stepper drive controller and a second stepper drive. The two stepper drives and the power take-off element are force-coupled and drive-coupled by a mechanical coupling unit. A central unit controls the two stepper drive controllers by a control signal, in each instance. The control signals predetermine the stator reference field angle and the rotor reference field angle set by the stepper drive controller. The central unit has an overriding regulator for the position of the power take-off element, and a subordinate regulator for setting a tensioning moment for each stepper motor. The tensioning moments occur by setting a load actual angle at the stepper drive.

Abstract: A system and method are provided to allow the replacement of a costly electrically commutated blower or fan motor with a less efficient motor such as a permanent split capacitor motor operating at a predetermined speed, without regard to the specific electrically commutated motor command signals or programming being used by the original equipment manufacturer. A retrofittable control board is employed to activate the replacement motor by energizing the replacement blower motor when an electrically commutated blower motor command signal is observed on any one of the signal lines which are continuously monitored simultaneously.

Abstract: A motor driving apparatus includes a first module on which an inverter circuit configured to supply a driving current to a motor is mounted, a second module on which a control circuit configured to control the inverter circuit is mounted, and a third module on which a power circuit configured to supply direct-current (DC) power to at least one of the inverter circuit and the control circuit. The first module and the second module are attachable to and detachable from the third module.

Abstract: When it is not possible for a power generation device to operate coupled to an electric power system, an autonomous operation of connection and disconnection of a load of the power generation device is performed along an efficiency-characteristics curve within a speed range from a rated speed to a maximum speed in the efficiency-characteristics curve of an energy source. During the autonomous operation, an aperture command is outputted to an inlet valve of a water turbine and a first converter is operated in a converter mode when an operation preparation command is outputted by a control unit, a second converter is operated in an inverter mode when a voltage is established by of a DC linkage unit, and the load is connected when the operation preparation is completed.

Abstract: In an electric power conversion circuit, a gate controller executes a first operation. In the first operation, the gate controller performs control such that a first lower FET, a first upper FET, a second lower FET, and a second upper FET satisfy the following conditions: a condition that a first state in which the first lower FET is turned on, a second state in which both of the lower FETs are turned off, a third state in which the second lower FET is turned on, and a fourth state in which both of the lower FETs are turned off appear repeatedly in the order; and a condition that the first upper FET is turned on at a middle of a period of the second state and is maintained in an on state until a middle of a period of the third state.

Abstract: In a power network system (10A), a plurality of power routers including at least a first power router (100A) and a second power router (100B) are connected through respective input/output terminal parts in a multi-stage configuration. A predetermined amount of power is transmitted to the input/output terminal part of the power transmission destination (230A) through a first input/output terminal part (210A), the input/output terminal part of the second power transmission source (220A), and the DC bus (201A) in the second power router. The power network system includes as power information about power in the input/output terminal part of the power transmission destination, identification information of the first power transmission source (110A), and an intermediate measurement value of power received in the first input/output terminal part in a predetermined time period.

Abstract: A method for controlling an operation of a converter circuit adapted to regulate power transfer between a first voltage source and a second voltage source includes detecting a first voltage level of the first voltage source and a second voltage level of the second voltage source; calculating a power value based on the detected first voltage level and the detected second voltage level; comparing the calculated power value with a reference power value; and determining switching time of one or more switches in the converter circuit based on a compared result so as to regulate power transfer between the first voltage source and the second voltage source.

Abstract: A limited slip electric drive system for a motor vehicle is disclosed. The system uses an induction motor having a stator, and first and second rotors disposed for independent rotation within the stator. The rotors are each independently associated with one wheel of the vehicle and are able to slip when the vehicle goes around a turn. A traction inverter and control system monitors angular speeds of the rotors and determines which of the rotors is turning slower than the other, and controls the induction motor in accordance with the rotor having a lower speed so that a torque signal is generated in accordance with the rotor having the lower speed.

Abstract: A servomotor control device includes a servomotor control circuit for controlling an inverter such that an alternating current is supplied to a servomotor when receiving a safety signal, and for controlling the inverter such that the alternating current is not supplied to the servomotor when not receiving the safety signal, and a servomotor monitoring circuit for stopping the servomotor by stopping transmission of the safety signal to the servomotor control circuit when determining to stop the servomotor, and for stopping the servomotor by disconnecting supply of a direct current to the inverter with a power source disconnect circuit and stopping the transmission of the safety signal to the servomotor control circuit when determining that at least one of the power source disconnect circuit, the safety signal, and the servomotor control circuit is not normal.

Abstract: In a control unit for a robot, an inverter which drives a motor installed in a robot. A control circuit controls drive of the motor. A drive power circuit supplies DC power to the motor, and a control power circuit DC power to the control circuit. A backup power circuit supplies backup DC power to the control circuit when the DC power from the control power circuit to the control circuit is shut down. A first switch is arranged between the backup power circuit and the inverter, the first switch being selectively switched on and off to open and close. A first switch control section switches on the first switch such that the DC power in the backup power circuit is supplementarily supplied to the inverter when the motor is driven to be accelerated.

Abstract: A system and method includes a multiplexed motor controller for controlling multiple motors with a weight and volume penalty comparable to that of a single controller system and method by receiving a plurality of inputs indicating a status, prioritizing a plurality of sub-systems based on the status, multiplexing a plurality of operation commands in accordance with the prioritization, and generating a plurality of waveforms in accordance with the operation commands.

Abstract: An angle detector detects an operation angle of an electric actuator having an electric motor. The electric motor generates rotation force when being energized. The angle detector includes a controller. The controller calculates an average current flowing through the electric motor during operation of the electric actuator. The controller calculates the operation angle of the electric actuator from a predetermined formula by using the average current.

Abstract: In the state where a sensor used for controlling a first inverter has an abnormality, when rotation speed Ne of an engine is lower than a predetermined reference value Nref (S120), three phase-on control of a first inverter is performed (S190). This causes the rotation speed of the engine to be increased with an increase in rotation speed of a driveshaft. Operation control of the engine is started when the rotation speed Ne of the engine reaches or exceeds a threshold value Nst (S210 to S230).

Abstract: There is provided a power electronics device including: a first connection unit, a second connection unit, a power conversion unit and a control unit. The first connection unit and the second connection unit are connected to a first power line and a second power line of plural power lines. The power conversion unit converts power from one of the first and second connection units outputs converted power from the other of the first and second connection units. The control unit selects a master device from power electronics devices connected to a third power line that is one of the power lines including the first power line and the second power line, based on power conversion characteristic information of the power electronics devices. The master device controls other power electronics devices except the master device out of the power electronics devices, regarding output of power to the third power line.

Abstract: A power supply system has an n-phase electric machine, where n?1, and a controllable energy store serving to control and to supply electrical energy to the electric machine. The controllable energy store has n parallel power supply arms which each have at least two series-connected energy storage modules which each include at least one electrical energy storage cell with an associated controllable coupling unit, are connected on one side to a reference bus and are connected on the other side to one respective phase of the electric machine. In dependence on control signals, the coupling units either bridge the respectively associated energy storage cells or connect the respectively associated energy storage cells into the power supply arm.

Abstract: A method of operating a laundry treatment apparatus, in particular a washing machine, a laundry dryer, a heat pump laundry dryer or a washing machine having a drying function, is provided. The apparatus includes a control unit controlling the operation of the treatment apparatus, a laundry treatment chamber for treating laundry, a detector unit for detecting at least one operation parameter (T_inv) of the treatment apparatus, and a first variable speed motor unit adapted at least to drive the treatment chamber, and/or a compressor having a second variable speed motor unit for circulating a refrigerant fluid through a refrigerant loop of the laundry treatment apparatus.

Abstract: A method and arrangement in connection with an electric drive system are provided. The electric drive system includes an intermediate circuit with two or more supply units and two or more inverter units connected thereto, and an electric machine having two or more three-phase windings galvanically separated from each other. Two or more inverter units are connected to the three-phase windings. The arrangement also includes first main circuit switches to galvanically separate each supply unit from a supply, second main circuit switches to galvanically separate each supply unit from the intermediate circuit, first intermediate circuit switches to galvanically separate each inverter unit from the intermediate circuit, and second intermediate circuit switches to galvanically separate each inverter unit from the electric machine.

Abstract: An AC-AC power converter supplies AC power to an AC motor having a plurality of motor windings and a case connected to a ground. The AC-AC power converter architecture includes an asymmetric phase shift autotransformer/rectifier unit (ATRU) that converts an AC input to a DC output, wherein the asymmetric phase shift ATRU generates a common-mode AC voltage across the asymmetric phase shift ATRU. The common mode voltage is diverted to ground through motor case parasitic capacitance via a common-mode voltage pull-down circuit connected between each phase of the ATRU AC input and the ground.

Abstract: Systems, methods, devices, and computer readable media for controlling a digging operation of an industrial machine. A method includes determining a hoist bail pull associated with the industrial machine, determining a crowd torque limit value for a crowd drive based on the determined hoist bail pull of the industrial machine, and setting a crowd torque limit of the crowd drive to the crowd torque limit value to limit a torque associated with a crowd motor to the crowd torque limit value.

Abstract: In an electric power steering apparatus of the invention, a control circuit determines a command value of drive voltage supplied to a motor drive circuit based on an actual current through a motor and a target current. When the command value exceeds the previous value having a lower limit equivalent to a limit value representing the limit of the power supply from a battery, the control circuit controls the amount of discharge from the auxiliary power supply according to a difference between the command value and the previous value by increasing or decreasing a duty of switching devices. Thus, the power steering apparatus can save the energy of the auxiliary power supply for efficiently using the auxiliary power supply.

Abstract: A hand-held, battery powered tool (e.g., nutrunner, drill) includes an output head operatively connected to a motor, a plurality of battery cells, an ON/OFF start switch, a resistance sensor that measures a resistance of the output head to movement, and a controller. When the start switch is ON and the resistance sensed by the resistance sensor does not exceed a predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other and the motor in series. When the start switch is ON and the resistance sensed by the resistance sensor exceeds the predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other in parallel and to the motor.

Abstract: Power conversion systems and methods are provided for driving a plurality of motor loads, in which an autotransformer receives AC input currents and provides a plurality of multiphase outputs at a non-zero phase angle relative to one another, and the individual multiphase outputs are provided to corresponding motor drives with rectifiers to convert the multiphase outputs to DC electrical power, and inverters to convert the DC power to AC to drive corresponding motor loads.

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 double ended inverter system for an AC electric traction motor of a vehicle is disclosed. The inverter system serves as an interface between two different energy sources having different operating characteristics. The inverter system includes a first energy source having first operating characteristics associated therewith, and a first inverter subsystem coupled to the first energy source and configured to drive the AC electric traction motor. The inverter system also includes a second energy source having second operating characteristics associated therewith, wherein the first operating characteristics and the second operating characteristics are different, and a second inverter subsystem coupled to the second energy source and configured to drive the AC electric traction motor. In addition, the inverter system has a controller coupled to the first inverter subsystem and to the second inverter subsystem.

Abstract: A torque control device controlling torque of first and second mechanical units connected coaxially to each other through connecting members includes a controller generating first and second references from a command from a host system, first and second motors respectively driving the first and second mechanical units, first and second motor control units respectively controlling the first and second motors on the basis of the first and second references. The first and second references synchronously accelerate the first and second motors to first rotational speed, then increase rotational speed of the second motor according to a speed profile to produce torsional torque in the connecting members, decelerate the second motor to the first rotational speed after the torsional torque reaches a predetermined value, and synchronously decelerate and stop the first and second motors after a predetermined time period elapses.

Abstract: A double ended inverter system for an AC traction motor of a vehicle includes a fuel cell configured to provide a DC voltage, an impedance source inverter subsystem coupled to the fuel cell, a DC voltage source, and an inverter subsystem coupled to the DC voltage source. The impedance source inverter subsystem, which includes an ultracapacitor, is configured to drive the AC traction motor. The inverter subsystem is configured to drive the AC electric traction motor. The ultracapacitor is implemented in a crossed LC network coupled to the fuel cell.

Abstract: An object of the present invention is to suppress reverse of a vehicle on an up-hill road against an intention of a driver. A drive device for a vehicle according to the present invention includes: an estimator for estimating whether or not reverse of the vehicle occurs on an up-hill road; a rotating electric machine for generating electric power by rotation of a drive wheel in the vehicle when the vehicle reverses; a capacitor for electrically charging the electric power generated by the rotating electric machine; and a battery connected in parallel to the capacitor, wherein the estimator estimates that the reverse of the vehicle occurs when a current traveling road is an up-hill road and a vehicular speed is smaller than a threshold whereas the electric power of the capacitor is electrically discharged to the battery when the reverse of the vehicle is estimated and the amount of electric energy of the capacitor is greater than a certain threshold.

Abstract: A fuel/electric drive system having an internal combustion engine is disclosed, having a generator which is driven by the internal combustion engine and has a first stator winding set, having a first rectifier which is connected to the first stator winding set at the AC voltage end and to a first DC voltage circuit at the DC voltage end, and having a first inverter which is connected to the first DC voltage circuit at the DC voltage end and to a drive motor at the AC voltage end. In order to increase the robustness and availability of the fuel/electric drive system, the generator has a second stator winding set, with a second rectifier being connected to the second stator winding set at the AC voltage end and to a second DC voltage circuit at the DC voltage end, and a second inverter being connected to the second DC voltage circuit at the DC voltage end and to the drive motor at the AC voltage end.

Abstract: A double ended inverter system suitable for use with an AC electric traction motor of a vehicle is provided. The double ended inverter system cooperates with a first DC energy source and a second DC energy source, which may have different nominal voltages. The double ended inverter system includes an impedance source inverter subsystem configured to drive the AC electric traction motor using the first energy source, and an inverter subsystem configured to drive the AC electric traction motor using the second energy source. The double ended inverter system also utilizes a controller coupled to the impedance source inverter subsystem and to the inverter subsystem. The controller is configured to control the impedance source inverter subsystem and the inverter subsystem in accordance with a boost operating mode, a traditional inverter operating mode, and a recharge operating mode of the double ended inverter system.

Abstract: A movable barrier operator having control circuitry (206) to selectively cause movement of a corresponding movable barrier (203) and a power supply that is operably coupled to a mains (201) and is operably coupled to provide electrical motive power to components of the operator can be configurable to selectively disconnect a portion, but not all, of the power supply from the mains when full power availability for the components is not required. This power supply can comprise a less efficient first power supply (204) and a more efficient second power supply (205). In such a case, these teachings can provide for disconnecting (105) the first power supply from the mains when a higher level of power is not presently required. Meanwhile, the second power supply can continue to provide operating power to, for example, the aforementioned control circuitry to ensure ongoing functionality of the movable barrier operator.

Abstract: A control strategy for operating a plurality of prime power sources during propulsion, idling and braking and is applicable to large systems such as trucks, ships, cranes and locomotives utilizing diesel engines, gas turbine engines, other types of internal combustion engines, fuel cells or combinations of these that require substantial power and low emissions utilizing multiple power plant combinations. It is directed at a general control strategy for multi-engine systems where the power systems need not be of the same type or power rating and may even use different fuels. It is based on a common DC bus electrical architecture so that prime power sources need not be synchronized.

Abstract: A controller for operating a variable speed alternating current motor using inverters to which power is supplied from two or more power supplies including an energy accumulator has a first inverter for converting direct current supplied from the outside into alternating current, a power supply for accumulating direct current, a second inverter for converting direct current supplied from the power supply into alternating current, and an adder for adding the alternating current voltages outputted from the first and second inverters.

Abstract: A mobile machine may include one or more generator units, a plurality of electric propulsion motors, and a power-transfer system operable to transfer electricity from one or more of the generator units to one or more of the electric propulsion motors. The mobile machine may also include power-system controls that control the connection of the one or more electric propulsion motors to the power-transfer system. The power-system controls may selectively use a first motor-connection strategy for controlling when one or more groups of the electric propulsion motors are connected to the power-transfer system in series, and the power-system controls may selectively use a second motor-connection strategy for controlling when one or more groups of the electric propulsion motors are connected to the power-transfer system in series.

Abstract: An uninterruptible power supply has first and second input terminals, first and second inductors, first and second AC switch units, first and second storing devices and a control unit. The first and the second inductors are electrically connected to the first and the second input terminals. The first and the second AC switch units are electrically connected to the first and the second inductors for conducting input currents. The control unit is electrically connected to the first and the second AC switch units which may be turned on and off thereby to control the first and the second inductors which charge the input currents and discharge the input currents to the first and the second storing devices.