A drive system for an electrically driven motor vehicle and a method for operating the drive system, which increases the service life of a power module which is a component of a pulse inverter of the drive system.

A brushless direct-current (BLDC) motor has a connector, a stator, a rotor and a positioning module. The connector has three input ends for receiving three voltage signals, and a feedback end for receiving a feedback signal. The three voltage signals are transmitted to three windings of the stator. Rotation of the rotor is induced by interaction of magnetic fields of the three windings and a plurality of magnets of the rotor. The positioning module is fixed to the stator and has three Hall sensors for sensing positions of the magnets. The positioning module generates the feedback signal according to the positions of the plurality of magnets sensed by the three Hall sensors. The first voltage signal, the second voltage signal and the third voltage signal are adjusted according to the feedback signal.

An integrated circuit is provided, including an AD converter; a DC-DC converter converting a received first voltage into a second voltage and providing the second voltage as a power supply voltage of the AD converter; a control part controlling the AD converter and the DC-DC converter. The DC-DC converter includes a first switching element; a second switching element having one end coupled to a reference potential and the other end coupled to one end of the first switching element; a coil coupled to a connection point of the two switching elements; and a current detection part detecting a current flowing to the coil. The control part turns off the first switching element and turns on the second switching element, and after the current detected by the current detection part becomes equal to or smaller than a reference current value, turn off the second switching element to operate the AD converter.

A plurality of power supply circuits include a second power supply circuit for a CPU included in a control unit and a first power supply circuit for another circuit. An output voltage from the first power supply circuit is higher than an output voltage from the second power supply circuit. A range of input voltage is divided into three levels of voltage sub-ranges in accordance with a requirements specification. When the input voltage falls within a lower level voltage sub-range, both of an output function of the first power supply circuit and an output function of the second power supply circuit are stopped. When the input voltage falls within an intermediate level voltage sub-range, the output function of the first power supply circuit is stopped. When the input voltage falls within an upper level voltage sub-range, all circuits are controlled so as to operate.

A control unit calculates necessary power necessary to drive a motor in accordance with a torque designation value and a rotational speed of a motor, sets a voltage value to a predetermined voltage value, changes a current value in accordance with the necessary power, and drive the motor in a case in which the calculated necessary power is less than a predetermined threshold value, and sets the current value to a predetermined current value, changes the voltage value in accordance with the necessary power, and drives the motor in a case in which the calculated necessary power is equal to or greater than the predetermined threshold value.

The present invention easily inhibits an influence of a dead time on voltage control without requiring a user to consider a specific usage condition or the like of each motor control device. A control circuit (10) controls a step-down converter circuit (40) to step down a DC voltage to be applied to an inverter circuit (60) so that a duty of a PWM signal becomes greater than a dead time (Td).

A step-down chopper circuit having a filter reactor includes: a capacitor series circuit having a first capacitor and a second capacitor; a first series circuit having a semiconductor switching element and a diode, which is connected in parallel with the first capacitor, and a second series circuit having a diode and a semiconductor switching element, which is connected in parallel with the second capacitor; a chopper reactor whose one end is connected to a connection point of the first series circuit; and an output capacitor connected between the other end of the chopper reactor and a connection point of the second series circuit, in which a bypass current path with respect to the capacitor, which is configured to bypass a short-circuit current, is formed when one of the first series circuit and the second series circuit becomes a short-circuit state.

A low-voltage motor is provided that includes a rotor and a stator having two or more phase windings and a number of single-turn coils. Each phase winding comprises a plurality of the single-turn coils connected together. Each of the single-turn coils is a single conductive loop that includes only one conductor on each side of the single-turn coil.

An integrated circuit is provided, including an AD converter; a DC-DC converter converting a received first voltage into a second voltage and providing the second voltage as a power supply voltage of the AD converter; a control part controlling the AD converter and the DC-DC converter. The DC-DC converter includes a first switching element; a second switching element having one end coupled to a reference potential and the other end coupled to one end of the first switching element; a coil coupled to a connection point of the two switching elements; and a current detection part detecting a current flowing to the coil. The control part turns off the first switching element and turns on the second switching element, and after the current detected by the current detection part becomes equal to or smaller than a reference current value, turn off the second switching element to operate the AD converter.

Embodiments of the present disclosure relate to an electric motor drive system for driving a low-voltage motor. The low-voltage motor includes a rotor and a stator that comprises a number of single-turn coils. A motor drive controller can control the low-voltage motor. The motor drive controller includes a current source inverter. The current source inverter includes driver circuitry configured to generate switching commands, a variable current source and motor commutation circuitry. The variable current source can generate a variable current that regulates power in the low-voltage motor. The motor commutation circuitry receives the variable current and switching commands, and commutates phase currents that are output to the low-voltage motor.