A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.

A control device for controlling a linear actuator having a linear motor and a brake device includes a magnetic pole position estimation means to estimate which of a plurality of sections obtained by dividing a magnetic pole position of 0 to 360, the mover is located in on the basis of a direction of movement of the mover by pulse energization, a magnetic pole position setting means to perform direct current excitation at an estimated magnetic pole position estimated by the magnetic pole position estimation means and set the estimated magnetic pole position as a magnetic pole position of the mover, and a brake control means to turn on a brake device before pulse energization by the magnetic pole position estimation means is performed and turn off the brake device after the magnetic pole position estimation means estimates the section in which the mover is located.

A control device for controlling a linear actuator having a linear motor and a brake device includes a magnetic pole position estimation means to estimate which of a plurality of sections obtained by dividing a magnetic pole position of 0 to 360, the mover is located in on the basis of a direction of movement of the mover by pulse energization, a magnetic pole position setting means to perform direct current excitation at an estimated magnetic pole position estimated by the magnetic pole position estimation means and set the estimated magnetic pole position as a magnetic pole position of the mover, and a brake control means to turn on a brake device before pulse energization by the magnetic pole position estimation means is performed and turn off the brake device after the magnetic pole position estimation means estimates the section in which the mover is located.

A motor control method according to an embodiment of a present invention comprises the steps of: performing three-phase commutation in a first range section of a motor rotational speed in a brake mode of a motor; performing two-phase commutation in a second range section of the motor rotational speed performing one-phase commutation in a first range section of the motor rotational speed; and turning off commutation when the motor rotational speed is less than or equal to the first range section.

A motor control method according to an embodiment of a present invention comprises the steps of: performing three-phase commutation in a first range section of a motor rotational speed in a brake mode of a motor; performing two-phase commutation in a second range section of the motor rotational speed performing one-phase commutation in a first range section of the motor rotational speed; and turning off commutation when the motor rotational speed is less than or equal to the first range section.

A control system for mechanical braking devices is provided. The control system is designed to selectively slow, stop, and lock in place rotating machinery that is turning at an RPM that may be much greater than zero while helping minimize shock load on the rotating machinery. A fan brake control system is provided which can include: a fan brake; a position sensor; a microcontroller; an actuator; an operator interface; and a fan motor interface.

A control system for mechanical braking devices is provided. The control system is designed to selectively slow, stop, and lock in place rotating machinery that is turning at an RPM that may be much greater than zero while helping minimize shock load on the rotating machinery. A fan brake control system is provided which can include: a fan brake; a position sensor; a microcontroller; an actuator; an operator interface; and a fan motor interface.

Provided is a motor controller including: a rotation control unit configured to control a rotation of a motor; a brake control unit configured to control an operation of a brake for holding a rotor with respect to a stator of the motor; a rotation-state detection unit configured to detect a rotation state of the motor; a timer configured to measure, in a released state where an operation of the brake is released by the brake control unit, a time from an outputting of a command to change over a state of the brake to a locked state to a detection of a predetermined change in a rotation state of the motor by the rotation-state detection unit; and a determination unit configured to determine that a brake operation delay abnormality is present when the time, measured by the timer, is equal to or more than a predetermined threshold.

Provided is a motor controller including: a rotation control unit configured to control a rotation of a motor; a brake control unit configured to control an operation of a brake for holding a rotor with respect to a stator of the motor; a rotation-state detection unit configured to detect a rotation state of the motor; a timer configured to measure, in a released state where an operation of the brake is released by the brake control unit, a time from an outputting of a command to change over a state of the brake to a locked state to a detection of a predetermined change in a rotation state of the motor by the rotation-state detection unit; and a determination unit configured to determine that a brake operation delay abnormality is present when the time, measured by the timer, is equal to or more than a predetermined threshold.

There is disclosed a fault ride-through system for use in a power system comprising a synchronous generator driven by a prime mover. The fault ride-through system comprises a mechanical switch connected in parallel with a dynamic power dissipater, wherein the dynamic power dissipater comprises a solid-state switch connected in series with a braking resistor. A controller is configured to control the mechanical switch and the solid-state switch to control the current through the braking resistor, based on received data indicative of one or more operation parameters of the power system.