Abstract:
One embodiment describes a switching device system, which includes a first single pole switching device that selectively connects and disconnects a first phase of electric power to a first winding of a three phase motor; a second single switching device that selectively connects and disconnects a second phase of electric power to a second winding of the three phase motor; in which the first and second single pole switching devices control temperature of the motor by, at a first time, connecting the first phase and the second phase electric power to the motor.
Abstract:
One embodiment describes a method that includes, when a motor is disconnected from a power source: starting, using a control circuitry, a counter at a first voltage zero-crossing by either a source voltage or a back electromotive force generated by the motor; stopping, using the control circuitry, the counter at a next subsequent second voltage zero-crossing by either the source voltage or the back electromotive force; monitoring, using the control circuitry, a trend in counter values; and instructing, using the control circuitry, one or more switching devices to reconnect the power source to the motor after a local minimum in the counter value trend such that the source voltage is leading the back electromotive force.
Abstract:
One embodiment describes a motor starter, which includes a first single pole switching device that opens to disconnect power from a first winding of a motor; a second single pole switching device that closes after the first switching device opens to connect power to the first winding; a third single pole switching device closes after the second single pole switching device closes to increase power supplied to a second winding of the motor; a fourth single pole switching device that opens after the third single pole switching device closes to disconnect power supplied to a third winding of the motor and to reduce power supplied to the second winding; and a fifth single pole switching device that closes after the fourth switching device opens to connect power to the third winding.
Abstract:
One embodiment describes a tangible, non-transitory, computer-readable medium storing instructions executable by a processor of an operating coil driver circuitry. The instructions include instructions to instruct a switch to supply a specific current to an operating coil of a switching device using a pulse-width modulated signal; determine duty cycle of the pulse-width modulated signal; and determine wellness of the switching device based at least in part on the duty cycle of the pulse-width module signal.
Abstract:
A method and apparatus using electromagnetic switching in a two-step connection process is provided to minimize surge currents and torque oscillations in three-phase motors during starts.
Abstract:
One embodiment describes a tangible, non-transitory, computer-readable medium storing instructions executable by a processor in a control circuitry. The instructions include instructions to receive an instruction to make a switching device; determine, using the control circuitry, a voltage waveform of a power source; determine, using the control circuitry, a desired time to make the switching device based at least in part on the source voltage waveform; determine, using the control circuitry, an expected make time of the switching device; and determine, using the control circuitry, when to apply a pull-in current to make the switching device at the desired time based at least in part on the expected make time and the desired time to make.
Abstract:
A method and apparatus using electromagnetic switching in a two-step connection process is provided to minimize surge currents and torque oscillations in three-phase motors during starts.
Abstract:
One embodiment describes an operating coil driver circuitry, which includes a control circuitry that outputs a trigger signal and a reference voltage; an operational amplifier that compares the reference voltage to a node voltage, in which the node voltage is directly related to current flowing through an operating coil of a switching device and the operational amplifier outputs a logic high signal when the node voltage is higher than the reference voltage and outputs a logic low signal when the node voltage is lower than the reference voltage; and a flip-flop that outputs a pulse-width modulated signal to instruct a switch to supply a desired current to the operating coil based at least in part on the trigger signal and the signal output by the operational amplifier.
Abstract:
One embodiment describes a switching device system, which includes a first single pole switching device that selectively connects and disconnects a first phase of electric power to a first winding of a three phase motor; a second single switching device that selectively connects and disconnects a second phase of electric power to a second winding of the three phase motor; in which the first and second single pole switching devices control temperature of the motor by, at a first time, connecting the first phase and the second phase electric power to the motor.
Abstract:
One embodiment describes a wye-delta starter, which includes a first single pole, single current carrying path switching device that selectively connects and disconnects a first winding of a motor in a wye configuration; a second single pole, single current carrying path switching device that selectively connects and disconnects the first winding in a delta configuration, in which the first switching device and the second switching device are coupled via a first interlock; a third single pole, single current carrying path switching device that selectively connects and disconnects a second winding and a third winding of the motor in the wye configuration; a fourth single pole, single current carrying path switching device that selectively connects and disconnects the second winding in the delta configuration, in which the third switching device and the fourth switching device are coupled via a second interlock; and a fifth single pole, single current carrying path switching device that selectively connects and disconnects the third winding in the delta configuration.