A safety device for an actuator that can modulate power to an electric motor in response to a fault condition (e.g., stall). In one embodiment, the actuator can include a motor with a shaft, a sensor disposed in proximity to the shaft, and a control processor coupled with the sensor and the motor. The control processor can be configured to receive a signal from the sensor that conveys operating data that relates to rotation of the shaft, use the operating data to identify a fault condition on the motor, and change the motor from an energized condition to a de-energized condition in response to the fault condition.

A safety device for an actuator that can modulate power to an electric motor in response to a fault condition (e.g., stall). In one embodiment, the actuator can include a motor with a shaft, a sensor disposed in proximity to the shaft, and a control processor coupled with the sensor and the motor. The control processor can be configured to receive a signal from the sensor that conveys operating data that relates to rotation of the shaft, use the operating data to identify a fault condition on the motor, and change the motor from an energized condition to a de-energized condition in response to the fault condition.

Techniques for detecting pulse-width modulation (PWM) duty cycle errors are disclosed. The techniques include receiving a PWM signal for output to a gate drive of a motor controller and detecting a first duty cycle error associated with the PWM signal based on a comparison of the PWM signal with a corresponding PWM command. The techniques further include triggering, in response to detecting the first duty cycle error, a safe state at the gate drive of the motor controller.

Techniques for detecting pulse-width modulation (PWM) duty cycle errors are disclosed. The techniques include receiving a PWM signal for output to a gate drive of a motor controller and detecting a first duty cycle error associated with the PWM signal based on a comparison of the PWM signal with a corresponding PWM command. The techniques further include triggering, in response to detecting the first duty cycle error, a safe state at the gate drive of the motor controller.

A method for detecting a structural fault of an electric motor. The method includes: (i) acquiring a measurement signal of a physical parameter representative of the rotation of the electric motor, (ii) obtaining the high frequency component of the measurement signal, resulting in a corrected signal, (iii) applying a set of band-pass filters to the corrected signal resulting in a set of filtered corrected signals, (iv) determining a stator frequency and a rotor frequency, (v) computing a frequency signature vector, (vi) computing a temporal symptom vector from the frequency signature vector and the set of filtered corrected signals, and (vii) detecting a structural fault of the electric motor from the determined temporal symptom vector and from a classifier model.

A method for detecting a structural fault of an electric motor. The method includes: (i) acquiring a measurement signal of a physical parameter representative of the rotation of the electric motor, (ii) obtaining the high frequency component of the measurement signal, resulting in a corrected signal, (iii) applying a set of band-pass filters to the corrected signal resulting in a set of filtered corrected signals, (iv) determining a stator frequency and a rotor frequency, (v) computing a frequency signature vector, (vi) computing a temporal symptom vector from the frequency signature vector and the set of filtered corrected signals, and (vii) detecting a structural fault of the electric motor from the determined temporal symptom vector and from a classifier model.

An apparatus includes a housing, a first disconnect switch in the housing and having a first terminal configured to be coupled to a first unit (e.g., a first VFD or RVSS) external to the housing and a second disconnect switch in the housing and having first terminal configured to be couple to a second unit (e.g., a second VFD or RVSS) external to the housing. The apparatus further includes a first contactor in the housing and having a first terminal coupled to a second terminal of the first disconnect switch and a second terminal configured to be coupled to a motor and a second contactor in the housing and having a first terminal coupled to a second terminal of the second disconnect switch and a second terminal configured to be coupled to the motor, the second contactor mechanically interlocked with the first contactor.

An apparatus includes a housing, a first disconnect switch in the housing and having a first terminal configured to be coupled to a first unit (e.g., a first VFD or RVSS) external to the housing and a second disconnect switch in the housing and having first terminal configured to be couple to a second unit (e.g., a second VFD or RVSS) external to the housing. The apparatus further includes a first contactor in the housing and having a first terminal coupled to a second terminal of the first disconnect switch and a second terminal configured to be coupled to a motor and a second contactor in the housing and having a first terminal coupled to a second terminal of the second disconnect switch and a second terminal configured to be coupled to the motor, the second contactor mechanically interlocked with the first contactor.

A motor control method includes: acquiring a first rotational speed error of a rotor of a motor corresponding to a current moment; acquiring a speed compensation value for the rotor according to a preset speed drop graph, which represents a graphical representation of speed versus time when a rotational speed of the rotor drops; calculating an electric current compensation value according to the speed compensation value and a preset speed-current mapping model; acquiring an electric current reference value corresponding to the current moment, which is an electric current value for controlling the rotational speed of the rotor; and controlling the motor according to the electric current compensation value if the first rotational speed error is greater than a preset error, or controlling the motor according to the electric current reference value if the first rotational speed error is less than or equal to the preset error.

A motor control method includes: acquiring a first rotational speed error of a rotor of a motor corresponding to a current moment; acquiring a speed compensation value for the rotor according to a preset speed drop graph, which represents a graphical representation of speed versus time when a rotational speed of the rotor drops; calculating an electric current compensation value according to the speed compensation value and a preset speed-current mapping model; acquiring an electric current reference value corresponding to the current moment, which is an electric current value for controlling the rotational speed of the rotor; and controlling the motor according to the electric current compensation value if the first rotational speed error is greater than a preset error, or controlling the motor according to the electric current reference value if the first rotational speed error is less than or equal to the preset error.