An apparatus and method for suppressing torque generation of a three-phase motor, includes a torque determination device that determines a second torque value for suppressing a first torque value due to a zero phase sequence component current of the three-phase motor, a control amount determination device that determines a voltage control amount for generating the determined second torque value, and a controller that is configured to control the three-phase motor according to the determined voltage control amount.

The present disclosure relates to security mechanisms for electric motors and associated systems. For example, the present technology includes a powertrain assembly having (1) a motor having multiple sets of coils; (2) a drive circuitry electrically coupled to the multiple sets of coils; and (3) a security unit electrically coupled to the drive circuitry and the multiple sets of coils. The security unit is configured to short-circuit at least one set of the multiple sets of coils responsive to a signal from a controller. The signal indicates that the motor is, or has been, turned off.

Systems, methods, and apparatus related to a homing mechanism within a drive mechanism of a lacing engine for an automated footwear platform are described. In an example, the homing apparatus can include an indexing wheel, a plurality of Geneva teeth and a stop tooth. The plurality of Geneva teeth can be distributed around a portion of a perimeter of the indexing wheel. Each Geneva tooth of the plurality of Geneva teeth can include side profiles conforming to a first side profile that generates a first force when engaged by an index tooth on a portion of the drive mechanism. The stop tooth can be located along the perimeter of the indexing wheel between two Geneva teeth. Additionally, the stop tooth can include side profiles conforming to a second side profile that generates a second force when engaged by the index tooth.

A frequency converter adapted to be connected to another frequency converter via a direct current bus is provided. The frequency converter comprises: a positive bus interface adapted to be interconnected with a positive bus interface of the other frequency converter; an external bleeder resistor interface adapted to be interconnected with an external bleeder resistor interface of the other frequency converter; and a first control logic which controls a parallel connection, between the frequency converter and the other frequency converter and realized by a direct current bus, to be turned on or off. A corresponding frequency converter assembly, a control method, and a computer readable storage medium are also provided.

A holdup energy arrangement can include a motor control module configured to connect to motor power electronics to operate an inverter to control a motor. The motor control module can operate at a lower voltage than the motor power electronics. The arrangement can include a power supply operatively connected to the motor control module and configured to provide power the motor control module and a converter operatively connected to the power supply and configured to be electrically connected to a DC link capacitor of the motor power electronics. The arrangement can also include a logic control module configured to control the converter to selectively allow energy to flow from the DC link capacitor, through the converter, and to the power supply to provide holdup energy to the power supply with energy from the DC link capacitor.

A safety switching system and method for braking an electric motor in a mobile device. A multi-phase shorting system brakes the motor by diverting power from the motor windings. Multiple independent switching units each include a switch control unit controlling multiple normally-closed switches which, in response to a safety controller, close to connect a respective motor winding to electrical ground. An electromechanical brake system mechanically brakes the motor. An independent switching unit includes two normally-open switches which, in response to the safety controller, opens to activate an electromechanical brake. A feedback system communicates to the safety controller a switch failure of any of the switches either as a short circuit fault or an open circuit fault. The feedback system may include an analog and/or a digital feedback system. If a switch failure is detected, the safety controller may activate the multi-phase shorting system and the electromechanical brake system.

The invention relates to fluid drive systems used in fluid wells and brake systems for permanent magnet wellhead direct drives. The braking controller connects or disconnects a brake resistor from a back EMF. A variable frequency drive (VFD) drives the motor and communicates with the control circuitry of the brake controller. The control circuitry monitors the brake resistor and depending on the rotational speed and direction of the motor and operating state of the VFD, disconnects or connects the brake resistor. If the direction of the motor is in reverse and above a threshold speed, it connects the brake resistor. If the direction of the motor is in reverse and below the threshold speed, the control circuitry dissipates stored back EMF through the brake controller. The amount of stored back EMF corresponds to the time to empty a pump.

The invention relates to fluid drive systems used in fluid wells and brake systems for permanent magnet wellhead direct drives. The braking controller connects or disconnects a brake resistor from a back EMF. A variable frequency drive (VFD) drives the motor and communicates with the control circuitry of the brake controller. The control circuitry monitors the brake resistor and depending on the rotational speed and direction of the motor and operating state of the VFD, disconnects or connects the brake resistor. If the direction of the motor is in reverse and above a threshold speed, it connects the brake resistor. If the direction of the motor is in reverse and below the threshold speed, the control circuitry dissipates stored back EMF through the brake controller. The amount of stored back EMF corresponds to the time to empty a pump.

Generators and methods for shutting down generators in confined spaces. One generator includes an internal combustion engine, an alternator, a power outlet, and an electronic processor communicatively coupled to the engine. The electronic processor is configured to obtain an engine speed of the engine, and determine that the engine speed is below an engine speed threshold. The electronic processor is further configured to determine, in response to determining that the engine speed is below the engine speed threshold, that a predetermined number of a plurality of secondary parameters of the generator have crossed respective secondary thresholds. The electronic processor is further configured to shut down the generator in response to determining that the predetermined number of the secondary parameters have crossed the respective second thresholds.

Generators and methods for shutting down generators in confined spaces. One generator includes an internal combustion engine, an alternator, a power outlet, and an electronic processor communicatively coupled to the engine. The electronic processor is configured to obtain an engine speed of the engine, and determine that the engine speed is below an engine speed threshold. The electronic processor is further configured to determine, in response to determining that the engine speed is below the engine speed threshold, that a predetermined number of a plurality of secondary parameters of the generator have crossed respective secondary thresholds. The electronic processor is further configured to shut down the generator in response to determining that the predetermined number of the secondary parameters have crossed the respective second thresholds.