When a shift position is changed from a non-forward operating position to a forward operating position during a predetermined operation that shuts off gates of a first inverter and a second inverter and operates an engine, a step-up/down converter is controlled to gradually change the voltage of a high voltage-side power line toward a required voltage that is lower than a reverse voltage of a first motor.

When a shift position is changed from a non-forward operating position to a forward operating position during a predetermined operation that shuts off gates of a first inverter and a second inverter and operates an engine, a step-up/down converter is controlled to gradually change the voltage of a high voltage-side power line toward a required voltage that is lower than a reverse voltage of a first motor.

The invention relates to an arrangement for identifying an electrical line interruption during operation of a drive system (20), which comprises two parallel-connected DC motors (21, 41), which are mechanically coupled to one another by means of a part that is to be driven, a driver for driving the two parallel-connected DC motors (21, 41) and a measuring device for detecting different electrical variables of the drive system (20). The measuring device comprises a rotational speed determination apparatus (32) for determining the rotational speed of the two DC motors (21, 41) and for supplying a piece of rotational speed information representing the rotational speed. The measuring device further comprises a current measuring apparatus (27; 28) for determining a summation current flowing in the two DC motors (21, 41) and for supplying a piece of current information representing the summation current and a voltage determination apparatus (60; 61) for determining the terminal voltage of the two DC motors (21, 41) and for supplying a piece of voltage information representing the terminal voltage. A computation unit (70) is designed to ascertain a motor parameter (k.sub.) for the drive system (20) from the voltage information, the current information and the rotational speed information and to compare said motor parameter with a setpoint value (k.sub._set) of the motor parameter (k.sub.), wherein the presence of a line interruption to one of the two DC motors (21, 41) can be inferred from the result of the comparison.

The invention relates to an arrangement for identifying an electrical line interruption during operation of a drive system (20), which comprises two parallel-connected DC motors (21, 41), which are mechanically coupled to one another by means of a part that is to be driven, a driver for driving the two parallel-connected DC motors (21, 41) and a measuring device for detecting different electrical variables of the drive system (20). The measuring device comprises a rotational speed determination apparatus (32) for determining the rotational speed of the two DC motors (21, 41) and for supplying a piece of rotational speed information representing the rotational speed. The measuring device further comprises a current measuring apparatus (27; 28) for determining a summation current flowing in the two DC motors (21, 41) and for supplying a piece of current information representing the summation current and a voltage determination apparatus (60; 61) for determining the terminal voltage of the two DC motors (21, 41) and for supplying a piece of voltage information representing the terminal voltage. A computation unit (70) is designed to ascertain a motor parameter (k.sub.) for the drive system (20) from the voltage information, the current information and the rotational speed information and to compare said motor parameter with a setpoint value (k.sub._set) of the motor parameter (k.sub.), wherein the presence of a line interruption to one of the two DC motors (21, 41) can be inferred from the result of the comparison.

A conveying driving device of the invention includes a first motor which transmits power to a drive shaft of a roller; a second motor which transmits power to the drive shaft along with the first motor at a torque smaller than that of the first motor; and a controller which sets each of drive current setting values of the first motor and the second motor so that a total value of a consumption current of the first motor and the second motor becomes minimal in a steady state in which the roller rotates at a constant setting speed.

When a shift position is changed from a non-forward operating position to a forward operating position during a predetermined operation that shuts off gates of a first inverter and a second inverter and operates an engine, a step-up/down converter is controlled to gradually change the voltage of a high voltage-side power line toward a required voltage that is lower than a reverse voltage of a first motor.

The invention relates to an arrangement for identifying an electrical line interruption during operation of a drive system (20), which comprises two parallel-connected DC motors (21, 41), which are mechanically coupled to one another by means of a part that is to be driven, a driver for driving the two parallel-connected DC motors (21, 41) and a measuring device for detecting different electrical variables of the drive system (20). The measuring device comprises a rotational speed determination apparatus (32) for determining the rotational speed of the two DC motors (21, 41) and for supplying a piece of rotational speed information representing the rotational speed. The measuring device further comprises a current measuring apparatus (27; 28) for determining a summation current flowing in the two DC motors (21, 41) and for supplying a piece of current information representing the summation current and a voltage determination apparatus (60; 61) for determining the terminal voltage of the two DC motors (21, 41) and for supplying a piece of voltage information representing the terminal voltage. A computation unit (70) is designed to ascertain a motor parameter (k.sub.107 ) for the drive system (20) from the voltage information, the current information and the rotational speed information and to compare said motor parameter with a setpoint value (k.sub.107 .sub._.sub.set) of the motor parameter (k.sub.107 ), wherein the presence of a line interruption to one of the two DC motors (21, 41) can be inferred from the result of the comparison.

The invention relates to an arrangement for identifying an electrical line interruption during operation of a drive system (20), which comprises two parallel-connected DC motors (21, 41), which are mechanically coupled to one another by means of a part that is to be driven, a driver for driving the two parallel-connected DC motors (21, 41) and a measuring device for detecting different electrical variables of the drive system (20). The measuring device comprises a rotational speed determination apparatus (32) for determining the rotational speed of the two DC motors (21, 41) and for supplying a piece of rotational speed information representing the rotational speed. The measuring device further comprises a current measuring apparatus (27; 28) for determining a summation current flowing in the two DC motors (21, 41) and for supplying a piece of current information representing the summation current and a voltage determination apparatus (60; 61) for determining the terminal voltage of the two DC motors (21, 41) and for supplying a piece of voltage information representing the terminal voltage. A computation unit (70) is designed to ascertain a motor parameter (k.sub.107 ) for the drive system (20) from the voltage information, the current information and the rotational speed information and to compare said motor parameter with a setpoint value (k.sub.107 .sub._.sub.set) of the motor parameter (k.sub.107 ), wherein the presence of a line interruption to one of the two DC motors (21, 41) can be inferred from the result of the comparison.

A motor control, device that controls a motor, includes: a plurality of processors, each being adapted to generate information for generating a pulse width modulation (PWM) signal; a plurality of PWM signal generation circuits, each being provided corresponding to each of the processors and adapted to generate the PWM signal on the basis of the information that has been generated by the corresponding processor; and a switch circuit that selectively gives the information generated by each of the processors to any of the PWM signal generation circuits.

A motor control, device that controls a motor, includes: a plurality of processors, each being adapted to generate information for generating a pulse width modulation (PWM) signal; a plurality of PWM signal generation circuits, each being provided corresponding to each of the processors and adapted to generate the PWM signal on the basis of the information that has been generated by the corresponding processor; and a switch circuit that selectively gives the information generated by each of the processors to any of the PWM signal generation circuits.