Abstract: An electric motor system includes a battery, an inverter, an electric motor, a zero-phase switching arm and a control unit. The inverter converts DC power output from the battery into three-phase AC power and outputs the three-phase AC power to the electric motor. A rotor of the electric motor rotates by the three-phase AC power output from the inverter. A neural point of the electric motor is connected to the zero-phase switching arm. A zero-phase current flowing through respective windings of the electric motor is adjusted by switching of the zero-phase switching arm. By this means, in the electric motor system, torque is generated at the rotor also using the zero-phase current as well as a three-phase AC current flowing through the respective windings.

Abstract: An electric motor system includes a battery, an inverter, an electric motor, a zero-phase switching arm and a control unit. The inverter converts DC power output from the battery into three-phase AC power and outputs the three-phase AC power to the electric motor. A rotor of the electric motor rotates by the three-phase AC power output from the inverter. A neural point of the electric motor is connected to the zero-phase switching arm. A zero-phase current flowing through respective windings of the electric motor is adjusted by switching of the zero-phase switching arm. By this means, in the electric motor system, torque is generated at the rotor also using the zero-phase current as well as a three-phase AC current flowing through the respective windings.

Abstract: A controller for a free piston generator that is capable of more accurately controlling the behavior of a piston than conventional controllers is provided. During power generation of a free piston generator 10, a controller 18 controls the amount of power generation to cause the velocity of a piston 14 to reach a first velocity command value (for an expansion stroke) and a second velocity command value (for a compression stroke) by electric braking. During motoring, the controller 18 controls the amount of power supply to cause the velocity of the piston 14 to reach the first and second velocity command values. The controller 18 sets the first and second velocity command values by setting first and second velocity command values for a certain round-trip period based on a top dead center position and a bottom dead center position of the piston 14 for the previous round-trip period.

Abstract: An art of measuring a current with a suppressed influence of a switching noise is provided. The art disclosed by the present specification is a current sensor that measures an output current of a switching circuit. The current sensor is equipped with a magneto-optical element that is arranged at a current measurement point, a light source that radiates light onto the magneto-optical element, and a light receiver that receives transmitted light or reflected light of the magneto-optical element. The light source radiates light in synchronization with a carrier signal of the switching circuit. Light is radiated in synchronization with the carrier signal, and a current is measured with the aid of the light. Due to synchronization with the carrier signal, the current can be measured at timings other than a switching timing resulting from a PWM signal that is generated on the basis of the carrier signal.

Abstract: According to input parameters, a controller carries out: generation of a voltage command value for each of d- and q-axes; conversion of the voltage command value for each of the d- and q-axes into a voltage command value for each of the multiphase windings; and control of a multiphase inverter based on the voltage command value for each of the multiphase windings. The controller adds, to the voltage command value for the q-axis, a first compensation voltage value for compensating torque ripples to thereby output a compensated voltage command value for the q-axis. The first compensation voltage value contains m-th harmonic components in the AC motor and varies depending on the rotational angle of the rotor, the m corresponding to the number of phase of the multiphase windings. The controller uses, as the voltage command value for the q-axis, the compensated voltage command value for the q-axis.

Abstract: A structure for controlling an engine is simplified in a power generation device equipped on a vehicle which generates power by a driving force of an engine. An operation unit (32) outputs to a controller (12) drive operation information based on an operation of a user. The controller (12) controls a vehicle driving circuit (28) and determines an engine output power target value based on the drive operation information and a running state of the vehicle. An engine output power/control voltage table stored in a storage unit (34) is referred to, and a value of a control voltage (Va) correlated to the engine output power target value is determined. The controller (12) controls a voltage adjusting circuit (24) such that the control voltage (Va) is set to the value determined based on the engine output power/control voltage table.

Abstract: According to input parameters, a controller carries out: generation of a voltage command value for each of d- and q-axes; conversion of the voltage command value for each of the d- and q-axes into a voltage command value for each of the multiphase windings; and control of a multiphase inverter based on the voltage command value for each of the multiphase windings. The controller adds, to the voltage command value for the q-axis, a first compensation voltage value for compensating torque ripples to thereby output a compensated voltage command value for the q-axis. The first compensation voltage value contains m-th harmonic components in the AC motor and varies depending on the rotational angle of the rotor, the m corresponding to the number of phase of the multiphase windings. The controller uses, as the voltage command value for the q-axis, the compensated voltage command value for the q-axis.

Abstract: An induction machine includes a stator provided with stator windings and a first rotor provided with first rotor windings, and generates an induction current in one of the stator windings and the first rotor windings by a rotating magnetic field generated in the other of the stator windings and the first rotor windings. A synchronous machine includes a second rotor which is provided with second rotor windings connected to the first rotor windings and coupled to the first rotor, and a third rotor which is provided with permanent magnets and rotatable independent of the second rotor, and a torque acts between the second rotor and the third rotor due to the interaction between the rotating magnetic field generated in the second rotor windings and the field flux generated in the permanent magnets.

Abstract: An induction machine includes a stator provided with stator windings and a first rotor provided with first rotor windings, and generates an induction current in one of the stator windings and the first rotor windings by a rotating magnetic field generated in the other of the stator windings and the first rotor windings. A synchronous machine includes a second rotor which is provided with second rotor windings connected to the first rotor windings and coupled to the first rotor, and a third rotor which is provided with permanent magnets and rotatable independent of the second rotor, and a torque acts between the second rotor and the third rotor due to the interaction between the rotating magnetic field generated in the second rotor windings and the field flux generated in the permanent magnets.

Abstract: A switching operation of two switching elements is controlled by a controller. Specifically, by adjusting the duty ratio concerning the lower switching element, a capacitor voltage is controlled to a target value. This control is executed not only by simply performing a PI control with respect to the capacitor voltage based on a deviation from the target value, but also by performing feedback control with respect to battery power and output energy. Further, a scheduling factor based on battery voltage, capacitor voltage, and the like is employed to control the gain of the feedback control.

Abstract: A switching operation of two switching elements is controlled by a controller. Specifically, by adjusting the duty ratio concerning the lower switching element, a capacitor voltage is controlled to a target value. This control is executed not only by simply performing a PI control with respect to the capacitor voltage based on a deviation from the target value, but also by performing feedback control with respect to battery power and output energy. Further, a scheduling factor based on battery voltage, capacitor voltage, and the like is employed to control the gain of the feedback control.

Abstract: An accessory drive apparatus includes a power source, an accessory system that provides an input to the power source, an accessory driving source that drives the accessory system, and a power combination/distribution mechanism that is connected to the power source and the accessory system to transmit power from both the power source and the accessory driving source to the accessory system. With this arrangement, the accessory system is driven by a combination of power received from the accessory driving source and the power source.

Abstract: A direct-current power supply (40) is connected between the neutral points of two three-phase coils (24, 26) of a 2Y motor (22) constituted of the windings of the two three-phase coils (24, 26), which are connected in Y-connection and wound on a same stator, and to which three-phase alternating current power is severally supplied with a phase difference of a shifted angle between the windings from two inverter circuits (30, 32) having a positive pole bus (34) and a negative pole bus (36) for common use. A capacitor (38) is connected between the positive pole bus (34) and the negative pole bus (36). The electric potential difference between the neutral points of the three-phase coils (24, 26) is made larger or smaller than the voltage of the direct-current power supply (40) through the switching control of the inverter circuits (30, 32). Thereby, the capacitor (38) can be charged or discharged. Consequently, an inverter input voltage can be adjusted within a wide range.

Abstract: When the absolute values of the negative voltage V− and the positive voltage V+ of a rectangular wave to be applied to the three phase coils of the motor driven using a rectangular-waved voltage are different, time T1 and time T2 for the rectangular wave are adjusted such that the area A representing the absolute value of a time integration value of the negative voltage V− and the area B representing the absolute value of a time integration value of the positive voltage V+ becomes equal to each other. With this adjustment, the average voltage of the rectangular wave becomes of value 0, so that a DC component current is prevented from flowing into the three phase coils of the motor.

Abstract: A power plant outputs motive power by driving a motor (22) using electric power from a direct-current power source (32). When the direct-current power source (32) has a low temperature, the direct-current power source is rapidly heated, whereby the performance can fully be demonstrated.

Abstract: A direct-current power supply connecting the negative pole bus of an inverter circuit and the neutral point of a motor and a capacitor connecting the positive pole bus of the inverter circuit and the neutral point of the motor are provided for performing the switching control of the transistors T1-T6 of the inverter circuit on the basis of a phase voltage command value formed by the addition of a direct-current component and an alternating-current component. The voltage between the terminals of the capacitor is controlled on the direct-current component, and the driving control of the motor is performed on the alternating-current component. The supply voltage of the direct-current power supply can be made to be lower than a voltage necessary to drive the motor.

Abstract: An accessory drive apparatus includes a power source, an accessory system that provides an input to the power source, an accessory driving source that drives the accessory system, and a power combination/distribution mechanism that is connected to the power source and the accessory system to transmit power from both the power source and the accessory driving source to the accessory system. With this arrangement, the accessory system is driven by a combination of power received from the accessory driving source and the power source.

Abstract: A direct-current power supply (40) is connected between the neutral points of two three-phase coils (24, 26) of a 2Y motor (22) constituted of the windings of the two three-phase coils (24, 26), which are connected in Y-connection and wound on a same stator, and to which three-phase alternating current power is severally supplied with a phase difference of a shifted angle between the windings from two inverter circuits (30, 32) having a positive pole bus (34) and a negative pole bus (36) for common use. A capacitor (38) is connected between the positive pole bus (34) and the negative pole bus (36). The electric potential difference between the neutral points of the three-phase coils (24, 26) is made larger or smaller than the voltage of the direct-current power supply (40) through the switching control of the inverter circuits (30, 32). Thereby, the capacitor (38) can be charged or discharged. Consequently, an inverter input voltage can be adjusted within a wide range.

Abstract: A direct-current power supply connecting the negative pole bus of an inverter circuit and the neutral point of a motor and a capacitor connecting the positive pole bus of the inverter circuit and the neutral point of the motor are provided for performing the switching control of the transistors T1-T6 of the inverter circuit on the basis of a phase voltage command value formed by the addition of a direct-current component and an alternating-current component. The voltage between the terminals of the capacitor is controlled on the direct-current component, and the driving control of the motor is performed on the alternating-current component. The supply voltage of the direct-current power supply can be made to be lower than a voltage necessary to drive the motor.

Abstract: To improve accuracy in controlling battery output, a charge-storage element is connected in parallel to a plurality of power source units. Each power source unit includes a power source element, and power transmission and reception between the power source element and a neutral point N side can be controlled by controlling the ratio of time over which an open/close switch remains closed, determined according to which among the voltage at the power source element or a voltage across the power source unit is larger or smaller. As an output of each power source element can be controlled, accuracy in output control for the combination battery can be improved.