Permanent magnet motors (PMMs) can develop oscillations during motor startup that can cause damage to electric submersible pump (ESP) components. A system and method are presented for identifying mechanical and/or electrical caused oscillations in a PMM through the analysis of oscillations in current and torque measurements. A control system within a surface motor controller receives current and/or torque measurements from downhole sensors. The control system employs one or more algorithms designed to detect oscillations in the measurements. Upon detecting oscillations that are consistent with oscillations in the motor from mechanical or electrical causes, the control system automatically initiates protective action to prevent damage to the ESP components.

A monitoring and control apparatus communicates with an electrical drive of a subsurface artificial lift system to identify, predict and mitigate against failure of the artificial lift system. A monitoring and control apparatus: reads torque signals from the electrical drive or from a measurement device, produces a filtered torque signal; identifies frequency components of the filtered torque signal; compares the frequency components of the filtered torque signal with frequency components of a reference torque signal indicative of a healthy state of a pump motor of the artificial lift system to identify harmful frequencies in the filtered torque signal and generate a failure prediction index representing the likelihood of failure in comparison to a stable operation status; and then send a control signal to the electrical drive to adjust a frequency response of the pump motor so that the identified harmful frequency component is dampened.

A motor drive control device capable of reducing the occurrence of vibration in a simple circuit configuration is provided. The motor drive control device (1) includes a motor drive unit (2) that selectively energizes coils with a plurality of phases (Lu, Lv and Lw) of a motor (20) and a control circuit (4) that outputs a drive control signal (Sd) which is a PWM signal to the motor drive unit (2) and thereby controls driving of the motor (20) while switching energization phases of the coils with the plurality of phases (Lu, Lv and Lw) energized by the motor drive unit (2) in predetermined order. The control circuit (4) executes reduction control to temporarily reduce a duty ratio of the drive control signal (Sd) every time a period of 1/m (m is an integer of 2 or more) of a switching cycle of the energization phases elapses after switching the energization phases.

A motor drive control device capable of reducing the occurrence of vibration in a simple circuit configuration is provided. The motor drive control device (1) includes a motor drive unit (2) that selectively energizes coils with a plurality of phases (Lu, Lv and Lw) of a motor (20) and a control circuit (4) that outputs a drive control signal (Sd) which is a PWM signal to the motor drive unit (2) and thereby controls driving of the motor (20) while switching energization phases of the coils with the plurality of phases (Lu, Lv and Lw) energized by the motor drive unit (2) in predetermined order. The control circuit (4) executes reduction control to temporarily reduce a duty ratio of the drive control signal (Sd) every time a period of 1/m (m is an integer of 2 or more) of a switching cycle of the energization phases elapses after switching the energization phases.

Feedback control circuitry includes rate limiter circuitry configured to generate a rate limited position command based on a position command for a controlled component and based on a speed command for the controlled component. The feedback control circuitry also includes error adjustment circuitry configured to apply a control gain to an error signal to generate an adjusted error signal. The error signal is based on position feedback and the rate limited position command, and the position feedback indicates a position of the controlled component. The feedback control circuitry further includes an output terminal configured to output a current command generated based on the adjusted error signal.

In order to suppress vibration with a motor a load torque of which periodically fluctuates, an output torque of the motor is controlled to be periodically changed. In this case, in order to increase a vibration suppressing component by a direct power conversion apparatus, at least one of first control and second control is performed. In the first control, an output torque having a waveform including a fundamental frequency component of the load torque a fundamental frequency of which is a frequency in accordance with a fluctuation period of the load torque and at least one of a fourth harmonic and a sixth harmonic of a power source frequency of an AC power source is generated. In the second control, the output torque having a waveform including at least one of a second harmonic and a third harmonic of the fundamental frequency of the load torque and a second harmonic of the power source frequency of the AC power source is generated.

A system includes a motor configured to be coupled to a non-rigid load and a control system disposed within, or communicatively coupled to, a drive system configured to control an operation of the motor. The control system includes a processor and a memory accessible by the processor. The memory stores instructions that, when executed by the processor, cause the processor to generate a smooth move input profile to control the operation of the motor based on inputs specifying a desired operation of the motor, apply a notch filter having a notch filter frequency to the smooth move input profile to produce a filtered smooth move input profile, and send a command to the drive system based on the filtered smooth move input profile, wherein the command is configured to adjust the operation of the motor.

A system includes a motor configured to be coupled to a non-rigid load and a control system disposed within, or communicatively coupled to, a drive system configured to control an operation of the motor. The control system includes a processor and a memory accessible by the processor. The memory stores instructions that, when executed by the processor, cause the processor to generate a smooth move input profile to control the operation of the motor based on inputs specifying a desired operation of the motor, apply a notch filter having a notch filter frequency to the smooth move input profile to produce a filtered smooth move input profile, and send a command to the drive system based on the filtered smooth move input profile, wherein the command is configured to adjust the operation of the motor.

A motor drive that outputs a sinusoidal waveform utilizes power switching devices operable at high switching frequencies. The switching devices may be operated, for example, between twenty kilohertz and one megahertz. A first filter is included at the output of the motor drive which has a bandwidth selected to attenuate voltage components at the output which are at the switching frequency or multiples thereof such that the output voltage waveform is generally sinusoidal. Additional filtering is included within the motor drive to establish a circulation path for common mode currents within the motor drive. Further, a shield is provided adjacent to those components within the motor drive that may experience voltage or current waveforms at the switching frequency or multiples thereof to cause radiated emissions to establish eddy currents within the EMI shield rather than passing through the shield into the environment.

A motor drive that outputs a sinusoidal waveform utilizes power switching devices operable at high switching frequencies. The switching devices may be operated, for example, between twenty kilohertz and one megahertz. A first filter is included at the output of the motor drive which has a bandwidth selected to attenuate voltage components at the output which are at the switching frequency or multiples thereof such that the output voltage waveform is generally sinusoidal. Additional filtering is included within the motor drive to establish a circulation path for common mode currents within the motor drive. Further, a shield is provided adjacent to those components within the motor drive that may experience voltage or current waveforms at the switching frequency or multiples thereof to cause radiated emissions to establish eddy currents within the EMI shield rather than passing through the shield into the environment.