A motor control system for induction-type capacitor-start AC electric motors having starting and run windings starts the electric motors on AC power then, without stopping the motor, switches to using a variable-frequency motor drive (VFD) configured with a maximum power point tracking method to run the motor from solar power. In particular embodiments, the MPPT method is adapted to reduce power consumed by the motor by reducing frequency and voltage provided by the VFD when available solar panel power is insufficient for full power operation, and to increase frequency and voltage provided by the VFD when available solar panel power is greater than power absorbed by the motor.

A motor control system for induction-type capacitor-start AC electric motors having starting and run windings starts the electric motors on AC power then, without stopping the motor, switches to using a variable-frequency motor drive (VFD) configured with a maximum power point tracking method to run the motor from solar power. In particular embodiments, the MPPT method is adapted to reduce power consumed by the motor by reducing frequency and voltage provided by the VFD when available solar panel power is insufficient for full power operation, and to increase frequency and voltage provided by the VFD when available solar panel power is greater than power absorbed by the motor.

Included herein is a circuit comprising resistors, capacitors, relays, diode bridges, TRIACs, and DIACs mounted to a substrate. The circuit may be electrically connected to a user device containing a wide range of types and specifications of AC induction motors. The circuit may be installed plug-and-play onto a user device, without the need for tools, custom installation or deconstruction of a user device. Upon user direction or automatically, the circuit may inject DC current into the user tool which generates a stationary magnetic field inside the AC induction motor causing deceleration/arrestment of the AC induction motor's rotor. The circuit may prevent unintended acceleration of the rotor upon powering on the user device. Also included is a method for prevention of unintended acceleration of the rotor upon powering on the user device. Also included is a method for decelerating/arresting an AC induction motor.

A drive circuit for an electric motor includes a first filter, a rectifier, an inverter, and a line contactor. The first filter is configured to be coupled to an AC source and produces a filtered line frequency AC signal. The rectifier is coupled to the filter and produces a DC signal from the filtered line frequency AC signal. The inverter is coupled to the rectifier and produces an AC signal on an output node of the inverter. The AC signal is supplied to the electric motor to energize its stator windings. The line contactor is coupled between an output node of the first filter and the output node of the inverter. The line contactor supplies the output node of the inverter directly with the filtered line frequency AC signal to energize the stator windings when the inverter is disabled.

A circuit arrangement for generating a three-phase rotating field at least at an electrical consumer including at least one mains voltage input including a single-phase alternating current, a first phase strand connected to the mains voltage input and the electrical consumer, whose transported voltage includes a first outer conductor, a second phase strand, whose transported voltage corresponds to a second outer conductor, an energy storage, a switching element, through which the energy storage can be connected via a third phase strand for generating a third outer conductor, and a control unit that can detect at least one trigger point of the first phase strand and the switching element can be actuated at least at a detected trigger point of the first outer conductor of the first phase strand to close or open the third phase strand and to generate the third outer conductor.

This electric hoisting machine comprises: a motor driven by single-phase current; a cylindrical motor housing; a starting capacitor; a operating capacitor; a starting capacitor disconnecting switch; a control unit which controls the operation of the motor and which is covered by a control housing; and a housing case in which small-diameter cylindrical portions for accommodating the starting capacitor, a large-diameter cylindrical portion for accommodating the operating capacitor, and a large-diameter cylindrical portion for accommodating the starting capacitor disconnecting switch are integrally provided in a state of continuing in a horizontal row, the housing case being mounted on the outer periphery of the motor housing in such a manner that the cylindrical portions are oriented parallel to a rotation axis.

This electric hoisting machine comprises: a motor driven by single-phase current; a cylindrical motor housing; a starting capacitor; a operating capacitor; a starting capacitor disconnecting switch; a control unit which controls the operation of the motor and which is covered by a control housing; and a housing case in which small-diameter cylindrical portions for accommodating the starting capacitor, a large-diameter cylindrical portion for accommodating the operating capacitor, and a large-diameter cylindrical portion for accommodating the starting capacitor disconnecting switch are integrally provided in a state of continuing in a horizontal row, the housing case being mounted on the outer periphery of the motor housing in such a manner that the cylindrical portions are oriented parallel to a rotation axis.

Controllers for controlling hybrid motor drive circuits configured to drive a motor are provided herein. A controller is configured to drive the motor using an inverter when a motor commanded frequency is not within a predetermined range of line input power frequencies, and couple line input power to an output of the inverter using a first switch device when the motor commanded frequency is within the predetermined range of line input power frequencies.

Controllers for controlling hybrid motor drive circuits configured to drive a motor are provided herein. A controller is configured to drive the motor using an inverter when a motor commanded frequency is not within a predetermined range of line input power frequencies, and couple line input power to an output of the inverter using a first switch device when the motor commanded frequency is within the predetermined range of line input power frequencies.

A motor control system for induction-type AC electric motors having starting and run windings has a multiphase VFD drive with first and second phase outputs. A switching device with a first position, where a first output of the VFD drive is coupled to the run winding and a second output of the VFD drive couples to the start winding; and with the switching apparatus in second position, the run winding of the AC electric motor couples to an AC line input and the start winding of the AC electric motor couples through a capacitor and start switch to the AC line input. With the switching device in the first position, the second output of the VFD is configured to discontinue driving the start winding of the motor after the motor begins rotating.