Nidec Corporation

Nidec Elesys Corporation

Tomohiro Fukumura

Shota Ishigami

Masaki Yoshinaga

Akiko Ikeda

Atsushi Fujita

Taro Amagai

Kengo Araki

Linfeng Lan

Yuichi Takano

Keita Fukushima

Kotaro Kataoka

Takashi Koikegami

Koichi Takae

Akihiro Okamura

Isao Sanbonmatsu

A motor control device includes an inverter circuit to convert a DC power source voltage into a three-phase AC voltage and supply the three-phase AC voltage to the three-phase motor and a controller to generate three-phase PWM signals based on three-phase duty command values updated at a predetermined updating cycle and control the inverter circuit based on the three-phase PWM signals. The controller is configured or programmed to shift, when duty command values of at least two phases of the three-phase duty command values updated at a first update timing are the same, the duty command value of one phase of the duty command values of the two phases by a predetermined shift amount and shifts a duty command value of the one phase of the three-phase duty command values updated at a second update timing which is an update timing next to the first update timing by the shift amount in a direction opposite to a shift direction at the first update timing.

Motor control device

A first torque estimator determines a first torque estimation value according to a cross product method, and a second torque estimator determines a second torque estimation value according to an energy method. A torque weight adjuster adjusts, using a weighting coefficient calculated in accordance with a predetermined condition, weightings respectively applied to these two types of torque estimation values, and outputs a torque estimation value.

Motor control device and motor control method

A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimated position value signal.

Position estimation method and position control device

A command generation device according to an exemplary embodiment of the present invention includes a command receiving unit that receives a high-level command value related to motion of a motor from a host device, and an internal target generation unit that generates an internal target value of the motor, including a position target value and a rotational speed target value, based on the high-level command value. The internal target generation unit includes a feedback calculator that generates the internal target value corrected based on a difference between the high-level command value and the internal target value, and generates the internal target value corrected in a cycle shorter than a cycle of receiving the high-level command value with the command receiving unit.

Command generation device and command generation method

An offset of an output voltage of a magnetic sensor caused by an external magnetic field is removed. A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor that is arranged at a predetermined mechanical angle with respect to the first magnetic sensor and detects the rotational position of the rotor; a signal amplifier that amplifies a difference between a first signal which is a signal output from the first magnetic sensor and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generator that converts an output signal of the signal amplifier into a pulse signal.

Motor

An offset of an output voltage of a magnetic sensor caused by an external magnetic field is removed. A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor arranged at a position shifted by &#x3c0;/N in a rotation direction of the rotor with respect to the first magnetic sensor when the number of pole pairs is N; a signal amplifier that amplifies a difference between a first signal which is a signal output from the first magnetic sensor and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.

A motor according to a disclosed embodiment includes: a plurality of magnetic sensors that output sine wave signals having a certain phase difference in order in accordance with rotation of a rotor; a signal amplifier that amplifies a difference between an output signal of each of the plurality of magnetic sensors and an average signal that is an average of the output signals of the plurality of magnetic sensors; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.

A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor arranged at a rotation center of the rotor; a signal amplifier that amplifies a difference between a first signal, which is a signal output from the first magnetic sensor, and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.

An SR motor includes a rotor including N rotor salient poles where N is an integer of 2 or more, a stator including M stator salient poles where M is an integer of 3 or more, a shaft rotatably connected to the rotor, a sensor magnet that is fixed to an outer circumference of the shaft and includes an S pole and an N pole alternately arranged in the circumferential direction of the shaft, and three magnetic sensors opposed to the sensor magnet. The number of poles of the sensor magnet is N.

Reluctance motor and motor system including reluctance motor

A motor system includes a reluctance motor and a circuit connected to the reluctance motor. The reluctance motor includes a rotor including N rotor salient poles where N is an integer of 2 or more, a stator including M stator salient poles where M is an integer of 3 or more, 3-phase coils to excite the stator salient poles, and a sensor to detect a rotational position of the rotor. The circuit applies 120-degree conduction to the 3-phase coils when the rotor is rotated in a first direction from a stopped state (initial position), and applies 180-degree conduction to the 3-phase coils when the rotor is rotated in a second direction that is opposite to the first direction from the stopped state.

Motor system including reluctance motor

In one implementation, a motor module according to the present invention includes: a motor driving circuitto drive a motor M; and a position estimation deviceto output an estimated position signal of a rotor R of the motor M. It also includes: a motor control circuitto supply a command voltage value to the motor driving circuitin response to a pulse signal; and a variable step-size memorystoring variable step-size information, which defines an amount of displacement of the rotor R per pulse of the pulse signal. The estimated position signal is an analog or digital signal. Upon receiving a pulse signal, the motor control circuitdetermines the command voltage value based on an estimated position value of the rotor R acquired from the position estimation deviceand the variable step-size information read from the variable step-size memory. The motor driving circuitchanges the position of the rotor R based on the command voltage value.

Growing community of inventors

Kyoto, Japan

Tomohiro Fukumura