Abstract: A motor control apparatus that controls a first motor and a second motor that are synchronized includes a first motor control unit configured to control a driving voltage of the first motor based on the torque current instruction value, which is output based on a torque current of the first motor for the first motor, and a second motor control unit configured to control a driving voltage of the second motor based on the torque current instruction value, which is output based on a torque current of the second motor for the second motor, wherein the first torque correction unit or the second torque correction unit corrects the torque current instruction value for the first motor or the toque current instruction value for the second motor based on the torque current of the first motor and the torque current of the second motor.

Abstract: A hybrid electric vehicle which may effectively determine a point in time of shift pattern change and a method of controlling a shift pattern therefor are disclosed. The method includes determining whether or not a request for shift pattern change is received, determining HEV mode related conditions, in response to a determination that the request for shift pattern change is received, and changing a shift pattern according to the request for shift pattern change, in response to a determination that the HEV mode related conditions are satisfied.

Abstract: Disclosed is a drive train including a drive shaft, a drive machine, and a planetary gearbox having three drives and three outputs, wherein one output is connected to the drive shaft, one drive is connected to the drive machine, and a second drive is connected to an electric differential drive. The differential drive can be connected directly to a network without a frequency converter, in order that the operation of the drive train is possible without a frequency converter.

Abstract: An alternative energy generating apparatus is provided. The apparatus comprises a stationary metal coil or coils positioned by, above, below, or beside a magnet or a rotor of magnets with one or more imbedded magnets (e.g., rare earth magnets). Magnets may be imbedded along an outer part of a disc-like rotor. The one or more coils may be held in a coil plate apparatus, essentially parallel to the magnet rotor. The provided apparatus further comprises a shaft having a gear ratio for turning the rotor of magnets, such as by hand or by a motor in order to achieve a high turning velocity. The magnets generate an electromagnetic field, which when rotated against the stationary metal coils, produce an electric current.

Abstract: A vehicle includes an engine, a first MG, a second MG, a main battery which can be charged and discharged, and a heating device. The heating device includes an exhaust heater which uses an exhaust heat of the engine, and a heat pump system which uses an electric power of the main battery. A hybrid control device determines a start timing of the heating device, based on a coolant temperature and a SOC. Specifically, the start timing of the heating device is determined such that a timing that the coolant temperature reaches a target temperature matches a timing that the SOC reaches a target value. After a warming-up operation is completed, an EV travelling of the vehicle can be executed according to the electric power of the main battery charged in the warming-up operation, and a fuel consumption of the engine is improved.

Abstract: A method and architecture processing electrical energy regenerated from an aircraft, to address drawbacks posed by customary solutions for dissipating low energy of resistors, conventionally ceramics, which require a significant volume of ceramic and an additional power converter. The method and architecture return energy to an electric generator to convert the energy into mechanical energy. The architecture includes a reversible electric generator, driven by a thermal machine and configured to deliver an AC voltage, electric actuators, and a voltage converter circuit with multiple links. The circuit includes AC voltage rectifiers for voltage originating from the generator and power converters arranged on the multiple links to drive as many electric actuators. The converter circuit also includes a mechanism for electrical energy inverse transmission applied to the generator operating in a motor mode.

Abstract: A battery system for a movable object is mounted on the movable object having a charger and a load unit including a plurality of loads electrically driven for different purposes. The battery system is provided with a plurality of battery packs, a power control circuit for changing a connection state between the battery packs and the charger and a connection state between the battery packs and the load unit, a memory unit for storing operation information, an estimation unit for estimating a power consumption pattern in the operation cycle based on the operation information and a controller for switching the power control circuit to cover the power consumption by the load unit according to the power consumption pattern.

Abstract: A control device of a hybrid vehicle minimizes fuel consumption by an internal combustion engine while controlling, for a preset period that substantially corresponds to an update cycle of an instructed fuel consumption change rate, an electrical charge-discharge energy balance of a battery to have a predetermined value, (i) by setting, in a predetermined update cycle, the fuel consumption change rate based on travel pattern information and a target electrical charge-discharge balance and (ii) by setting an engine output power increase/decrease amount based on the instructed fuel consumption change rate and the target drive power.

Abstract: A control apparatus of a hybrid vehicle has an engine, a motor, an engine-driven generator, and a battery. A controller determines an engine output based on an efficiency function that is defined by a drive power of the vehicle, a generated electric power from the generator, and a discharged electric power from the battery. The determined engine output controls the efficiency function to be kept in a value range that includes a maximum efficiency value of the efficiency function.

Abstract: A gradient determination control unit releases the hold of a gradient determination result when a state where a road surface gradient detected by a gradient detection unit is smaller than a gradient release determination threshold value continues for a second predetermined time or longer if a vehicle is determined to be in a traveling state by a traveling state determination unit, and releases the hold of the gradient determination result when the road surface gradient detected by the gradient detection unit becomes smaller than the gradient release determination threshold value if the vehicle is determined to be in a stopped state by the traveling state determination unit.

Abstract: A motor includes a frame, a shaft rotatably mounted onto the frame, and at least one disc mounted onto the shaft. At least one permanent magnet is mounted on the disc, and at least one electromagnet and at least one coil are mounted to the frame in rotational magnetic proximity to the permanent magnet. A battery is connectable to the electromagnet and the coil for energizing the electromagnet and for receiving electrical current from the coil for charging the battery. A relay switch controls the transmission of electrical power from the battery to the electromagnet. A sensor generates a signal to the relay switch to activate electrical power to the electromagnet upon sensing that the permanent magnet is positioned with respect to the electromagnet such that a magnetic force generated by the electromagnet would be effective for inducing movement of the permanent magnet and consequent rotation of the disc.

Abstract: A separately excited synchronous machine (1b1k) with an excitation circuit on the side of the rotor includes an excitation winding (3) and a power supply for the excitation winding (3) as well as a switching element (8a, 8e) for connecting the power supply to the excitation winding (3). Further, the synchronous machine (1b1k) comprises a first stator-side primary winding (5a5f) and a first rotor-side secondary winding (6a6f). Moreover, the synchronous machine (1b1k) may comprise a) a tap of the first rotor-side secondary winding (6d) connected to a control element (9a, 9e) of the switching element (8a, 8e) or b) a second rotor-side secondary winding (14d), which is coupled to the first stator-side primary winding (5a5f) and connected to a control element (9a, 9e) of the switching element (8a, 8e).

Abstract: An estimation section calculates estimated currents corresponding to switching modes, which are provisionally set by a mode setting section. A mode determination section determines one of modes, which has a smallest difference between the estimated currents and command currents, to be a final switching mode. A drive section drives an inverter in the switching mode determined by the determination section. The estimation section uses transient-state inductances as coefficients of time differentiation of currents in voltage equations used for estimation of the estimated currents. These are different from steady-state inductances, which are coefficients of multiplication of currents and electric angular velocity.

Abstract: A vehicle power system including an unregulated alternator; a saturable reactor receiving an output AC voltage from the alternator and generating a reduced AC voltage in response to a bias signal; and an active rectifier rectifying the reduced AC voltage to a DC voltage.

Abstract: A system and method for efficiently regulating the fuel consumption of a variable speed combustion engine used to control loads such as a hoist motor in a mobile gantry crane based on load motor speed commands issued by a crane operator. The system and method can rely on a programmable logic controller to issue engine fuel commands to regulate engine speed based on interpolations derived from data representing the relationship between load motor voltage and engine speed and data representing the relationship between engine speed and engine power capacity. The method may also be used in modified form by combustion engines which need digital fixed speed commands.

Abstract: A hybrid vehicle is driven by a power unit which includes: a first rotating machine including a first rotor, a first stator, and a second rotor, wherein the number of magnetic poles generated by an armature row of the first stator and one of the first rotor and the second rotor are connected to a drive shaft; a power engine, wherein an output shaft of the power engine is connected to the other of the first rotor and the second rotor; a second rotating machine; and a capacitor. The hybrid vehicle includes: a state detector that detects a charge state of the capacitor; and a controller that controls the power unit. The controller controls the output of the power engine, based on a remaining capacity of the capacitor when driving the power engine in order to start the hybrid vehicle. Accordingly, it is possible to achieve reduction in the size and cost of the power unit and enhance the driving efficiency of the power unit.

Abstract: The invention relates to an electric device (1) comprising an alternating current electric motor (3) and a control inverter (5) for controlling the phase or phases of the motor (3). The motor (3) comprises, on at least one winding of at least one phase (PA, PB, PC), a point (Ma, Mb, Mc) for measuring a voltage relative to a predefined potential (M), the measurement point (Ma, Mb, Mc) being chosen so that it divides the winding into a first (Za1; Zb1; Zc1) and a second (Za2; Zb2; Zc2) portion such that the electromotive forces (ea1, ea2) induced in the two portions are phase-shifted relative to one another and means (11A; 11B; 11C) for measuring the voltage between the measurement point and the predefined potential. The invention also relates to an associated method for measuring electromotive forces.

Abstract: A method for the identification without shaft encoder of magnetomechanical characteristic quantities of a three-phase asynchronous comprising: —constant voltage impression U1? in ? axial direction in order to generate a constant magnetic flux; —test signal voltage supply U1? in ? axial direction of the asynchronous motor, whereby the ? axial direction remains supplied with constant current; —measuring signal current measurement I1? in ? stator axial direction of the asynchronous motor; —identification of mechanical characteristic quantities of the asynchronous motor based on the test signal voltage U1? and on the measuring signal current I1?, whereby the rotor can execute deflection movements. Method can also be used for control of electrical drives. An identification apparatus for the determination of mechanical characteristic quantities of an asynchronous motor and for motor control, whereby the identified characteristic quantities can be used to determine, optimize and monitor a motor control.

Abstract: A power converting device is disclosed that can reduce switching loss occurring in a voltage source inverter that drives an AC motor. It is possible to supply DC power to the voltage source inverter from both a voltage source rectifier, which converts AC power from an AC generator into DC power, and a battery. A first switching circuit is inserted between the voltage source rectifier and the AC generator, and the battery is connected to the output side of the voltage source rectifier. A second switching circuit is inserted between the battery and the voltage source inverter. A third switching circuit and a reactor are inserted in series between the input side of the voltage source inverter and the input side of the voltage source rectifier. At least one of an upper arm and a lower arm of the voltage source rectifier can be chopper controlled.

Abstract: An apparatus for use in a wellbore is provided that in one embodiment includes a load, a motor coupled to the load to provide electrical power to the load and an alternator directly coupled to the motor driving the motor. In one aspect, the apparatus further includes a switch between the alternator and the motor that in a first position connects the alternator to the motor in a first configuration that rotates the motor in the clockwise direction and in a second configuration that rotates the motor in the counterclockwise direction.

Abstract: A drive system of an electrically driven dump truck is capable of achieving an operational feeling in which the operation amount of the accelerator pedal is well balanced with the output horsepower of the electric motors, particularly at the time of slow traveling. To achieve this, the target motor output horsepower Pm0 corresponding to the operation amount of an accelerator pedal 1 is calculated. The target motor torque Tr1R, Tr1L is calculated on the basis of the target motor output horsepower Pm0 and the rotational speed ?R, ?L of electric motors 12R, 12L respectively. The acceleration torque limit values of the electric motors 12R, 12L corresponding to the operation amount of the accelerator pedal 1 are calculated, respectively. Then, smaller values are selected, as motor torque instruction values TrR, TrL, between the acceleration torque limit value and the target motor torque Tr1R, Tr1L to control inverters 73R, 73L, respectively.

Abstract: In an AC motor driving circuit, a current-type rectifier circuit having a filter circuit and first bidirectional switches bridge-connected to the filter circuit is provided in an output of an AC power supply. An AC motor is connected to an output of the rectifier circuit through a voltage-type inverter. One terminal of each of second bidirectional switches is connected to corresponding one of output terminals of the current-type rectifier circuit. The other terminals of the second bidirectional switches are collectively connected to one terminal of a series circuit having a DC power supply and a reactor. The other terminal of the series circuit is connected to one output terminal of the current-type rectifier circuit. With this configuration, a large capacitor for a DC link can be dispensed with, so that a reduction in circuit size and weight can be attained.

Abstract: An alternating current motor control system constituted of: a control unit; a cycloconverter functionality; a phase control functionality; and a semiconductor switching unit comprising a plurality of electronically controlled semiconductor switches each associated with a particular winding of a target alternating current motor and each independently responsive to the control unit. In one embodiment the semiconductor switching unit is arranged to connect the windings of the target alternating current motor to a three phase power input in one of a star and a delta configuration responsive to the control unit.

Abstract: In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.

Abstract: A power generation system includes a prime mover, a generator mechanically connected to the prime mover, the generator including a field winding portion and an armature winding portion, a direct current bus node, a first variable frequency drive having an input electrically connected to the bus node and an output electrically connected to the armature winding portion, and an inverter having an input electrically connected to the bus node and an output electrically connected to the field winding portion.

Abstract: The motor generator set described here has unique circuitry which allows for the combined electrical output of two generators to be paired up with one another as well as the output of a battery in a manner that maximizes there output. Diodes are provided in this circuitry to direct the flow of current effectively.

Abstract: A motor control unit controls the input electric power of a MG unit to thereby suppress variations of a system voltage and stabilize the system voltage. The torque control of an AC motor and the input electric power control of the MG unit are executed independently from each other, so that the torque control and the input electric power control are stabilized. Further, torque variation zeroing control for correcting a phase of a pulse waveform voltage is executed so that a difference between a first estimated torque computed based on a torque control detection current vector of the AC motor and a second estimated torque computed based on a detection motor current vector is reduced to zero. Thus, uncomfortable torque variation is suppressed in a transient condition of the input electric power control of the MG unit.

Abstract: A hybrid vehicle includes: first and second rotary electric machines; a matrix converter connecting the first and second rotary electric machines to each other to provide AC to AC power conversion between both the rotary electric machines; a battery connected to an electrical path branched off between the matrix converter and the second rotary electric motor; an inverter interposed among the battery, the matrix converter and the second rotary electric machine to convert AC power to DC power and vice versa; and a controller. The controller activates the first rotary electric machine with power fed from the battery and restrains the change in torque output of the second rotary electric machine at the activation of the first rotary electric machine.

Abstract: A hybrid electric vehicle includes, in one example, a motor-generator driven by an engine to generate alternating current, wherein the motor-generator is further configured to start the engine, a motor for driving the vehicle, a diode rectifier to rectify alternating current generated by the motor-generator, an inverter connected to a feed circuit between the diode rectifier and the motor to convert direct current in the feed circuit into alternating current, a power supply connected to a line connecting the diode rectifier with the inverter, a first feed circuit to supply current to the motor to drive the vehicle through the diode rectifier and the inverter in series a second feed circuit to connect the motor-generator with the power supply while bypassing at least the diode rectifier, and an alternating current converter provided in the second feed circuit.

Abstract: An axial gap type motor/generator is provided with a stator, a rotor and an alternating current control device. The alternating current control device executes alternating current control of a single phase or multiple phase alternating current flowing in the coils. The alternating current control device includes a superpositioning control section and a frequency component control section. The superpositioning control section produces the alternating current by superpositioning a plurality of frequency components including a first order fundamental wave component and a plurality of higher harmonic wave components that have frequencies equal to integer multiples of a frequency of the fundamental wave components and are of orders that are equal to values of the integer multiples. The frequency component control section controls a relationship among the frequency components such that two pairs of the frequency components whose orders differ by two are aligned with respect to each other.

Abstract: A drive system for an electrically driven dump truck is capable of enabling electric motors for traveling to make full use of the output horsepower of the prime mover up to an output limit of the prime mover. A target motor horsepower corresponding to an operation amount of an accelerator pedal is calculated and an available maximum horsepower for the electric motors out of the maximum output horsepower of the prime mover is calculated in response to the actual revolution speed of the prime mover. The horsepower coefficient corresponding to the instantaneous revolution speed deviation is calculated. The available maximum horsepower for the electric motors is modified by the horsepower coefficient to determine a second target motor horsepower. The target motor horsepower is limited to not exceed the second target motor horsepower so as to control the torque of the electric motors.

Abstract: A transition wiring system is provided. The transition wiring system may include one or more traction motors, a first generator, and a second generator. The transition wiring system may also include a first device, a second device, and a third device, each device configured to block reverse current flow. The transition wiring system may further include a single transition contactor disposed between the first generator and the second generator. The first generator and the second generator are configured to be selectively operable in-series and in-parallel.

Abstract: A system for using a generator to simultaneously power a variable frequency motor drive locally and provide clean power to a grid comprising an electric generator supplying alternating current to a power conversion system. The power conversion system includes a converter changing generator AC output to direct current (DC); a capacitor bank that filters the DC from the converter and outputs a DC bus power; a grid inverter capable of replicating grid power from the DC bus power; and an output filter for supplying power to the power grid. A variable frequency motor drive receives DC bus power from the power conversion system. The variable frequency motor drive may be operatively connected to the power conversion system, or integrated therein.

Abstract: In a motor-generator control system for controlling a motor-generator, first and second sets of multiphase windings of a motor-generator are arranged to be spatially shifted in phase from each other. An allocating unit is configured to, upon input of workload request for the motor-generator, determine a first torque to be allocated to the first set of multiphase windings and a second torque to be allocated to the second set of multiphase windings. A resultant torque of the first torque and second torque meets the input workload request for the motor-generator. An energizing unit is configured to energize the first set of multiphase windings to create the first torque and energize the second set of multiphase windings to create the second torque.

Abstract: A controller for a motor and a control method for a motor change an operating condition of each motor, considering difference in operating conditions, such as loss and temperature, thus making it possible to reduce a total loss in a plurality of motors. The controller includes a first motor operating condition calculator and a second motor operating condition calculator which calculate the estimated values of losses incurred when a first motor and a second motor are driven, and a DC voltage control unit which carries out, on a motor having a largest estimated value of loss, the processing for changing a supply voltage to change the voltage of DC power supplied to inverters by a DC/DC converter, thereby reducing the difference between a phase voltage, which is the resultant vector of the voltages across terminals of the motor, and a target voltage set on the basis of an output voltage of the DC/DC converter.

Abstract: A matrix converter (38) converts three-phase AC power input from a first motor-generator (MG1) directly to three-phase AC power for driving a second motor-generator (MG2) and outputs the resultant three-phase AC power, without rectifying the three-phase AC power generated by the first motor-generator (MG1) once to DC power as in an example using a conventional three-phase full-wave rectification inverter. In a power supply system for a vehicle (14), the three-phase AC power is transmitted and received between two motor-generators (MG1, MG2) more directly, by means of the matrix converter (38). Therefore, power loss can be reduced, as compared with a conventional example in which the three-phase AC power is once converted to DC power. Thus, a power supply system for a vehicle with improved energy efficiency and a vehicle including the same can be provided.

Abstract: A motor control unit executes a system voltage stabilization control for suppressing variation in a system voltage by operating reactive power of a motor/generator unit including an AC motor, and executes a conversion power control to control the output power of a voltage boosting converter to a command value. A target power operation amount necessary for stabilizing the system voltage is distributed to a motor/generator power operation amount command value and to a conversion power operation amount correction value. The target power operation amount can be obtained by being shared by the motor/generator unit and the voltage boosting converter, even when the target power operation amount is in excess of a limit value of power control amount of the motor/generator unit.

Abstract: V-phase upper-arm open phase detecting circuit outputs a permission signal to allow U-phase lower-arm MOSFET to be conductive when the V-phase voltage is higher than the positive electrode potential. In response to this permission signal, U-phase lower-arm driver circuit drives U-phase lower-arm MOSFET. V-phase lower-arm open phase detecting circuit outputs a permission signal to allow U-phase upper-arm MOSFET to be conductive when the V-phase voltage is lower than the negative electrode potential. In response to this permission signal, U-phase upper-arm driver circuit drives U-phase upper-arm MOSFET. Thereby, a MOS rectifying device capable of rectifying even when an open phase occurs, a driving method thereof, and a motor vehicle using thereof can be provided.

Abstract: A coordination control device of a power output apparatus includes a coordination control unit. The coordination control unit calculates an intermediate value between the maximum value and minimum value among voltage controls for a first motor generator, and voltage control from an AC voltage control generation unit to generate an AC voltage across neutral points of first and second motor generators, and outputs a value that is each phase voltage control for the first and second motor generators minus the calculated intermediate value to a signal generation unit as the final voltage control for the first and second motor generators.

Abstract: A hybrid electric vehicle includes, in one example, a motor-generator driven by an engine to generate alternating current, wherein the motor-generator is further configured to start the engine, a motor for driving the vehicle, a diode rectifier to rectify alternating current generated by the motor-generator, an inverter connected to a feed circuit between the diode rectifier and the motor to convert direct current in the feed circuit into alternating current, a power supply connected to a line connecting the diode rectifier with the inverter, a first feed circuit to supply current to the motor to drive the vehicle through the diode rectifier and the inverter in series a second feed circuit to connect the motor-generator with the power supply while bypassing at least the diode rectifier, and an alternating current converter provided in the second feed circuit.

Abstract: A motor control unit controls the input electric power of a MG unit to thereby suppress variations of a system voltage and stabilize the system voltage. The torque control of an AC motor and the input electric power control of the MG unit are executed independently from each other, so that the torque control and the input electric power control are stabilized. Further, torque variation zeroing control for correcting a phase of a pulse waveform voltage is executed so that a difference between a first estimated torque computed based on a torque control detection current vector of the AC motor and a second estimated torque computed based on a detection motor current vector is reduced to zero. Thus, uncomfortable torque variation is suppressed in a transient condition of the input electric power control of the MG unit.

Abstract: In a hybrid vehicle control apparatus, a motor control unit executes input power control on a MG unit to stabilize a system voltage. This input power control for MG unit is executed independently from torque control on an AC motor so that the input power control and the torque control are stabilized. The motor control unit further adjusts a current control gain for torque control in accordance with an input power amount of the MG unit. As a result, the current control gains of a q-axis current and a d-axis current for torque control are varied in correspondence to variations in torque variation rate in the q-axis direction and the d-axis direction in accordance with the input power amount, so that the torque is restricted from varying with variations in the q-axis current or the d-axis current.

Abstract: An electric power supply system for driving an electric rotating machine has a generator supplied with driving power from an engine to generate alternating-current electric power and a matrix converter as an alternating-current to alternating-current direct converter supplied with the alternating-current electric power to output arbitrary alternating-current electric power. By driving a motor with the alternating-current electric power supplied from the matrix converter, only one time electric power conversion is carried out to provide high efficiency in the whole system. In addition, electric power loss can be reduced so as to enhance a motor output when the system is applied to a vehicle power supply system.

Abstract: Torsional oscillation of a shaft in a swing drive system of an excavator is minimized by monitoring torsional strain of the shaft. An electric motor provides torque to the shaft in response to a drive signal provided by a converter. A compensation circuit produces a compensation signal as a function of torsional strain of the shaft. A field excitation circuit or regulator powers a converter as a function of the compensation signal such that a counter torque is provided to the shaft and torsional oscillation of the shaft is reduced.

Abstract: An electric motor control system including a generator, an AC motor, a power converter for driving the AC motor using a DC output voltage of the generator, and an electric motor controller for controlling the power converter. The electric motor controller controls the power converter by predicting a change in the DC voltage.

Abstract: The system (CVT) includes a first electrical machine (M1) with a first rotor (R1) provided with a multiphase winding (W1) and fixed firmly to the shaft (1) of the internal combustion engine (ICE) and a second rotor (R2) or intermediate rotor coaxial with the first rotor (R1) and carrying first magnetic means (PM1) operatively cooperating with the winding (W1) of the first rotor (R1), the intermediate rotor (R2) being coupled with at least one axle (2) of the motor vehicle, and a second rotary electrical machine (M2) coaxial with the first (M1) and including a stator (ST), which is arranged on the opposite side of the intermediate rotor (R2) to the first rotor (R1) and is provided with a multiphase winding (W2), as well as the intermediate rotor (R2) which also carries second magnetic means operatively cooperating with the winding (W2) of the stator (ST), a first inverter and a second inverter (I1, I2) of which the a.c.

Abstract: The present invention relates to a propeller drive arrangement for vessels used in water-borne traffic, and specifically to a propeller drive arrangement containing a propulsion unit, and to such an arrangement, which contains a propulsion unit, which is turnable relative the hull of the vessel. Particularly the present invention relates to a system and a method for braking a motor of a propulsion unit. The solution for braking the propulsion unit according to the present invention is based on short-circuiting a permanently magnetized motor.

Abstract: A variable-voltage variable-frequency power source for an electric motor that drives a re-circulation pump for a boiling water nuclear reactor. The power source has a semiconductor electric power converter and a speed controller for controlling the semiconductor electric power converter. When a part of the semiconductor electric power converter comes into an inoperative state, that part is electrically disconnected, and the variable-voltage variable-frequency power source temporarily stops outputting power, thereby idling the re-circulation pump. Thereafter, the power source re-starts outputting power before the re-circulation pump completely stops. Thus, the re-circulation pump keeps operating, without stopping.

Abstract: A method is for controlling a multi-phase electrical ship propulsion motor that is supplied with electric energy via a power converter. The ship propulsion motor is preferably a permanently excited motor with at least three windings. The phase currents flowing in the windings are controlled via the power converter to minimize the body noise emitted by the electrical ship propulsion motor.

Abstract: An engine start system includes a starter starting an engine, a starter drive relay controlling the starter and an engine ECU connected to a starter switch for controlling on/off of the starter drive relay based on a predetermined start condition. The engine start system further includes a normally closed relay connected to the starter switch, the engine ECU and the starter for establishing a de-energized state between the starter switch and the starter upon energization from the engine ECU to an exciting coil and establishing an energized state between the starter switch and the starter upon de-energization of the exciting coil. The engine ECU includes a circuit energizing the exciting coil of the normally closed relay upon turn-on of the engine ECU.