Sections of a linear motor track can each include a single power sensor configured to detect a power current in an erroneous state and one or more reference sensors configured to detect reference currents in erroneous states. The power sensor can be arranged between multiple drive coils of a section and a DC power rail (or “mid-bus”) for the drive coils. The power sensor can produce a single isolated output to a processor for the section, and the processor, in turn, can compare the output to a threshold for determining an error. The one or more reference sensors can be arranged between lower switches and a DC-reference bus, thereby providing a DC-referenced sensing signal for the drive coil currents. By referencing the processor to the same rail as the DC-referenced current sensing circuit, the reference sensors can produce outputs to the processor without any need for isolation.

System for detecting failures on a linear motor track

One or more embodiments are described for preventing controller windup in a motion control system. An example system includes a regulator that receives an input command to adjust a motion control variable of a mechanical system that includes a motor, the regulator configured to generate a first torque command based on the input command and an output torque from the motor. The system further includes a motor control module that receives the first torque command to generate an input torque command that is sent to the motor. The system further includes an anti-windup module that is configured to generate an anti-windup command based on the first torque command and the output torque, the anti-windup command being added to the input command that is sent to the regulator.

Compensator anti-windup for motion control systems

The invention provides a variable-frequency speed regulation control method. The method comprises vector control, a speed loop is an outer loop, a current loop is an inner loop, and regulation of thespeed loop comprises steps of S1, reading a target speed feedback omega fb and a moment saturation mark FLAG; S2, calculating a speed given omega ref of the speed loop according to the saturation markFLAG and the target speed; S3, calculating a speed difference value omega between the speed given omega and the speed feedback omega ; S4, calculating a proportional term and an integral term according to the speed difference value omega , and calculating speed loop output Tout=TP+TI; and S5, adjusting the output Tout of the speed loop according to a torque amplitude limitingvalue Tmax, and setting the saturation mark FLAG at the same time to indicate whether the current speed loop is in a saturated state or not, FLAG=false indicating that the speed loop is in an unsaturated state, and FLAG=true indicating that the speed loop is in a saturated state. The method is advantaged in that by setting the speed of the speed loop, outputting amplitude limiting and judging andpreprocessing an integral term, rigidity of the speed loop is improved, and robustness of the system is enhanced.

Variable-frequency speed regulation control method

A system and method for speed regulation of a VFD circuit via an anti-windup control scheme that provides consistent speed response with no overshoot is disclosed. A control system for operating the VFD circuit includes a feedback controller programmed to receive a speed of a motor operating responsive to an initial torque command and process the speed of the motor to generate a feedback controller output. A feedforward controller of the control system is programmed to process a speed reference to generate a feedforward controller output. A command module of the control system is programmed to determine a torque command based on the processed outputs of the feedback and feedforward controllers and operate the VFD circuit to control the motor according to the torque command.

Zhu Peijun

Papers

System and method for consistent speed regulation in a variable frequency drive