The present invention discloses a motor system without a hall sensing element. The motor system comprises a first output pin, a second output pin, an auxiliary pin, a stator, a rotor, a primary coil, and an auxiliary coil. Both the primary coil and the auxiliary coil surround the stator. The primary coil is coupled to the first output pin and the second output pin. The auxiliary coil is coupled to the auxiliary pin. The auxiliary coil is configured to determine a phase switching time point. The motor system detects the zero point of the voltage of the auxiliary pin, so as to detect the position of the rotor and determine the phase switching time point.

The present invention discloses a motor system without a hall sensing element. The motor system comprises a first output pin, a second output pin, an auxiliary pin, a stator, a rotor, a primary coil, and an auxiliary coil. Both the primary coil and the auxiliary coil surround the stator. The primary coil is coupled to the first output pin and the second output pin. The auxiliary coil is coupled to the auxiliary pin. The auxiliary coil is configured to determine a phase switching time point. The motor system detects the zero point of the voltage of the auxiliary pin, so as to detect the position of the rotor and determine the phase switching time point.

A control device (1) is configured to reduce the commutation angle error ε of a three-phase (u, v, w) EC motor (2.2) connected via a y-configuration. The three phases (u, v, w) are commutated via a motor control (3) including a rotor position sensor (4) and a control circuit (10). The rotor position sensor (4) senses the relative angular position of the rotor using the neutral-point potential at the neutral point of the y-configuration. The control circuit (10) is configured to impose a desired field weakening current component on the motor control (3) for reducing the commutation angle error ε.

A gate drive semiconductor device includes: external terminals to which PWM control signals are supplied; external terminals outputting a drive signal for driving a three-phase BLDC motor; external terminals to which the counter electromotive voltage generated by driving the three-phase BLDC motor is supplied; a zero-cross determination unit generating an interrupt signal indicating timing at which the counter electromotive voltage intersects with a midpoint potential of the three-phase BLDC motor based on the PWM control signal and the counter electromotive voltage; and an external terminal outputting the interrupt signal.

A sensor-less detection circuit includes a first voltage adjustment circuit providing a first output voltage at a first node using one of three input voltages. A second voltage adjustment circuit provides a second output voltage at a second node using all three, or only two, of the three input voltages. The second voltage adjustment circuit acts as an internal virtual neutral point for detecting a zero crossing event of the motor. A differential amplifier is coupled with the first and second nodes and outputs a third output voltage at a third node. A reference buffer has a reference voltage input and provides a fourth output voltage at a fourth node. A comparator is coupled with the third and fourth nodes and outputs a fifth output voltage at a fifth node, the fifth voltage indicating a zero cross event.

Provides are a control device for a three-phase synchronous motor in which a position detection accuracy of a rotor can be improved when one three-phase synchronous motor is driven by a plurality of inverters, and an electric power steering device using the same. A control device for a three-phase synchronous motor includes: a three-phase synchronous motor including a first three-phase winding and a second three-phase winding; a first inverter connected to the first three-phase winding; a second inverter connected to the second three-phase winding; a first control device that controls the first inverter on the basis of a rotor position of the three-phase synchronous motor; and a second control device that controls the second inverter on the basis of the rotor position of the three-phase synchronous motor. The first control device estimates the rotor position on a basis of a neutral point potential of the first three-phase winding and a neutral point potential of the second three-phase winding.

A motor driver device supplies drive voltages to three phase coils of a stator in a brushless DC motor based on a detection result of a position of a rotor in a sensorless manner. In a position detection section, two phase coils are set as a target coil pair and a remaining one phase coil is set as a non-target coil, and with respect to all combinations of target coil pairs, a first process of applying a pulse voltage from a first direction to the target coil pair and a second process of applying a pulse voltage from a second direction opposite to the first direction to the target coil pair are executed. In the first and second processes, power supply to the non-target coil is stopped. The position of the rotor is detected based on voltages generated in the non-target coil in each first process and each second process.

An applied voltage decision unit 510 performs in parallel, a process of determining three-phase AC commands V1u* to V1w* of a voltage applied to a motor by an inverter based on a position, of a rotor of a motor, detected by a position sensor with an output A, and a process of determining three-phase AC commands V2u* to V2w* of the voltage applied to the motor by the inverter based on a neutral point voltage VN of the motor. A PWM modulator 507 alternately outputs a PWM signal according to the three-phase AC commands V1u* to V1w* and a PWM signal according to the three-phase AC commands V2u* to V2w* to the inverter. A control device determines whether or not the position sensor with the output A has failed by comparing the position, of the rotor, detected by the position sensor with the output A with a position, of the rotor, estimated from a neutral point voltage VN of the motor.

A device for controlling a motor having a stator and a rotor, the stator being provided with at least one winding, the motor being controlled by a control module, the control device including: at least one transformation module for transforming a source signal taken from at least one of the terminals of the winding into a floating image signal representative of a counter-electromotive force induced in the winding. The transformation module has: a time constant determined from characteristics of the motor and/or characteristics of the control module; at least one first terminal connected to at least one of the terminals of the winding, and a second terminal, the first and second terminals being likely to have floating potential relative to the fixed reference terminal.

Disclosed are a motor control device that can accurately estimate a rotor position based on a neutral point potential even when a load increases, and a brake control device that is driven by the motor control device. The motor control device 3 includes a three-phase synchronous motor 4 including a three-phase winding, an inverter 31 connected to the three-phase winding, a control unit 6 for controlling the inverter based on a rotor position of the three-phase synchronous motor, and a rotational position estimation unit 2 for estimating a rotor position d based on a neutral point potential Vn of the three-phase winding. The rotational position estimation unit estimates a rotor position selectively using one or more of a plurality of detected values of the neutral point potential according to a pre-estimated value of the rotor position and a voltage application state to the three-phase winding.