Abstract: A mean vehicle speed Va and a mean variation .DELTA.Va are factors reflecting a current driving condition and an expected driving condition of a vehicle, which relate to a charge-discharge amount of a battery. A target state SOC* of the battery is calculated from the mean vehicle speed Va and the mean variation .DELTA.Va. The charge-discharge amount of the battery increases with an increase in mean vehicle speed Va and mean variation .DELTA.Va. The lower charging state of the battery results in the higher charge-discharge efficiency. The structure of the present invention sets the target state SOC* of the battery and controls the actual state of the battery to the target state SOC*, thereby enhancing the charge-discharge efficiency of the battery and ensuring a sufficient supply of electric power required for driving the vehicle.

Abstract: A synchronous motor control system which can freely regulate n-phase electric currents in a synchronous motor to control the characteristics of the synchronous motor. The synchronous motor control system can enhance the output torque per unit weight of a synchronous motor (40) simultaneously with reducing torque ripples. The waveform of three phase alternating currents is freely corrected over a range of +30 degrees from a specified electrical angle, at which a target phase current drawing a sine-wave curve reaches its peak value. It is assumed that this range of .+-.30 degrees corresponds to a range of 0 degree to 60 degrees. By way of example, the waveform is controlled to the peak value of the phase current in a range of 0 degree to 28 degrees. The correction of the phase current is carried out for the target phase which produces the primary magnetic flux of a revolving magnetic field.

Abstract: A power output apparatus of the invention includes a clutch motor (30) and an assist motor (40) that allow energy output from an engine (50) driven at a driving point of high efficiency to be converted to energy expressed as the product of a revolving speed and a torque of a drive shaft (22) and to be output to the drive shaft (22). In case that a large torque is required, for example, when the vehicle starts on a rising slope or runs at a low speed, the engine (50) is driven at a high-energy driving point having a large torque and a high efficiency. This structure causes large electric power to be generated by excess energy greater than the energy generally consumed and enables a battery (94) to be charged with the large electric power.

Abstract: The prior art technique should return the voltage applied to a synchronous motor to zero in the process of measurement of an electrical angle. This causes foreign noises. The structure of the present invention utilizes the fact that the electrical angle of a three-phase synchronous motor 40 depends upon the inter-coil inductances. The procedure of the present invention applies a predetermined voltage for measurement to each combination of coils, and measures variations in electric currents flowing through the respective coils. The electric current flowing through each coil is attenuated in the presence of a driving current in the three-phase synchronous motor 40, compared with the case in the absence of a driving current. The procedure of the present invention accordingly refers to a table 122A to correct the observed values of electric currents based on the variations in electric currents, and refers to another table 122B to read the electrical angle .pi.

Abstract: An electrical angle detecting device for detecting the electrical angle of a synchronous motor utilizes differences in inductance between phases with the angle of a rotor 50 to determine electrical angle. Voltage is applied across predetermined phases, the currents Iu, Iv, Iw flowing through U, V, W phases as a function of the differing inductance with angle of the rotor 50 are simultaneously detected, and the electrical angle is determined from relationships among the three currents stored in memory beforehand. In a first stage, the electrical angle is determined in the 0-.pi. range or the .pi.-2.pi. range by an approximation calculation and in a second stage the asymmetry of the maximum currents produced by the voltage applied across the phases is utilized to ascertain the range in which the electrical angle falls. the electrical angle can thus be unambiguously ascertained to enable sensorless detection of rotor position (electrical angle) even when the rotor is at rest or is rotating slowly.

Abstract: A power output apparatus 20 includes an engine 50, a clutch motor 30 having rotors 31 and 33 respectively linked with a crankshaft 56 and a drive shaft 22, an assist motor 40 attached to a rotor-rotating shaft 38, a first clutch 45 for connecting and disconnecting the rotor-rotating shaft 38 to and from the crankshaft 56, a second clutch 46 for connecting and disconnecting the rotor-rotating shaft 38 to and from the drive shaft 22, and a controller 80 for controlling the motors 30 and 40. The controller 80 operates the clutches 45 and 46 according to the states of the engine 50 and the drive shaft 22 and changes the connection of the rotor-rotating shaft 38, so as to enable power output from the engine 50 to be efficiently converted by the motors 30 and 40 and output to the drive shaft 22.