A control circuit for a motor of a compressor includes an inverter control module configured to control power switching devices of an inverter to generate output voltages from a DC power supply. The output voltages are applied to windings of the motor. A current control module is configured to generate voltage signals based on a torque demand. The inverter control module controls the power switching devices according to the voltage signals. A selector is configured to output one of an open loop torque value and a closed loop torque value as the torque demand. An open loop torque module is configured to generate the open loop torque value. The open loop torque module is configured to apply an upper limit to the open loop torque value. The upper limit is based on a voltage of the DC power supply.

A fan and a motor drive device thereof are provided. The motor drive device is configured to drive a motor and includes a control management unit and a voltage converter. The control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed ranges, each corresponding to a specific output duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and output a voltage regulating signal, which is a pulse width modulation signal having a duty ratio corresponding to one of the rotation speed ranges in which the target rotation speed signal transmitted from the ECU falls. The voltage converter is connected between a power source and the motor, and is configured to regulate a voltage outputted to the motor in response to the voltage regulating signal having the specific duty ratio outputted from the control management unit, to regulate a rotation speed of the motor.

A combined motor controller, including: a first function module, including at least one power module powered by the mains supply to output a VDC power supply to power other modules; a second function module, including at least one motor control module including a microprocessor control unit (MCU) and an IGBT inverter; and a third function module, including at least one I/O module configured to transmit signals between a system main control board or a peripheral device and the motor control module. Each function module is provided with an independent metal or plastic shell and a first circuit board located in the shell, and the first function module, the second function module and the third function module are connected by mutually matched connectors for power supply or control signal transmission between the function modules.

An elevator control device includes a filter to remove a direct current component and a torque component derived from rope imbalance from a torque command value applied to a drive motor, and an inertia identifying mechanism to identify an inertia value of an elevator based on an output obtained when a speed detection signal is input into the filter, and an acceleration converting mechanism, which are connected in series, and an output obtained when the torque command value is input into the filter. As a result, the inertia value of a high-lift elevator can be calculated accurately.

A servo controller includes: a sinusoidal wave disturbance input unit for supplying a sinusoidal wave disturbance to a speed control loop including a speed command generator, a torque command generator and a speed detector; a frequency response calculator for estimating the gain and phase from the output of the speed control loop; a resonance frequency detector for detecting resonance frequencies at which the gain becomes maximum; a resonance mode characteristics analyzer for estimating resonance characteristics from the frequency response; and, a reference modal damping ratio retainer for retaining a reference modal damping ratio as a resonance characteristic corresponding to the reference lubricating condition, and the resonance mode characteristics analyzer calculates lubrication characteristics on the basis of the reference modal damping ratio and the measured modal damping ratio at the resonance frequency corresponding to the reference modal damping ratio.

A maximum acceleration identification system determines a suitable maximum acceleration for transitioning a given motion/motor system to a target position or velocity, taking the friction of the motion system into consideration. The maximum acceleration determined by the maximum acceleration identification system can then be used by the motion control system as the acceleration limit for generating motion profiles. Thus, motion profiles can be generated that are closer to the true maximum acceleration supported by the motion system without violating the mechanical and electrical constraints of the system as characterized in part by the viscous friction, resulting in a more time-optimal move. In some embodiments, the maximum acceleration identification system can automatically set the maximum acceleration of the control system's profile generator to be equal to the derived value, thereby eliminating the need for the maximum acceleration to be selected and set by the system designer.

A rotation speed control method and device of a motor, and a motor control system; the rotation speed control method of the motor comprises the following steps: conducting differential regulation on the output rotation speed of the motor to generate a feedback rotation speed signal (S1); generating a rotation speed deviation signal according to a target rotation speed signal and the feedback rotation speed signal (S2); conducting proportional integral regulation on the rotation speed deviation signal to generate a rotation speed control signal (S3); and controlling the rotation speed of the motor according to the rotation speed control signal (S4). The rotation speed control method, the rotation speed control device and the motor control system run steadily and have good dynamic performance, and are easy to implement.

The present invention belongs to the technical field of permanent magnet synchronous motor control, and provides a speed control method for a permanent magnet synchronous motor considering current saturation and disturbance suppression, which aims to effectively ensure that a current of the motor is always within a given range to avoid the problem of control performance reduction caused by the fact that the current gets into a saturation state, ensure the safety of a system, do not need to use unavailable state variables such as motor acceleration and the like, effectively estimate and compensate disturbances including parameters uncertainty and unknown load torque disturbance existing in a permanent magnet synchronous motor system, and rapidly and accurately control a speed of the motor finally. There is no need to configure a plurality of sensors in practical industrial application, so system building costs can be reduced on the one hand, and the stability of the system can be improved on the other hand. In conclusion, the technical solution proposed by the present invention has important practical application significance.

A motor drive controlling apparatus includes a controller that generates a drive control signal in response to input of a speed command signal and a motor driver that generates a drive signal in response to input of the drive control signal and outputs the drive signal to a motor, and the controller repeatedly generates the drive control signal in a period during which the speed command signal is inputted and stops generating the drive control signal in a period during which the speed command signal is not inputted to repeat an operation period in which the motor performs rotational operation and a stop period in which the motor stops operating in a non-excited state.

A power conversion apparatus includes a main circuit unit, a control unit, a current sensor, and a half-wave rectifier unit. The control unit includes current frequency calculation units and monitoring units. The current frequency calculation units calculate current frequencies based on at least either the rising timing or falling timing of current detection signals half-wave rectified by the half-wave rectifier unit. The monitoring units monitor the speed of a motor based on the current frequencies calculated by the current frequency calculation units.