Abstract: A motor system can include a motor configured to be operated according to at least a portion of an operation cycle specifying at least one target speed for the motor and a controller configured to obtain an estimated winding resistance of the motor, wherein the estimated winding resistance is determined based at least in part on an estimator gain factor, and wherein the estimator gain factor is inversely dependent on a speed of the motor; wherein the at least one target speed comprises at least one low speed such that at least a portion of the operation cycle is a low speed portion of the operation cycle, the at least one low speed having a speed of less than about 10 percent of a maximum speed of the operation cycle.

Abstract: A motor system can include a motor configured to be operated according to at least a portion of an operation cycle specifying at least one target speed for the motor and a controller configured to obtain an estimated winding resistance of the motor, wherein the estimated winding resistance is determined based at least in part on an estimator gain factor, and wherein the estimator gain factor is inversely dependent on a speed of the motor; wherein the at least one target speed comprises at least one low speed such that at least a portion of the operation cycle is a low speed portion of the operation cycle, the at least one low speed having a speed of less than about 10 percent of a maximum speed of the operation cycle.

Abstract: A motor system can include a motor, the motor including at least a rotor, and a controller configured to operate the motor. The controller can be configured to perform operations for operating the motor.

Abstract: Systems and methods of quasi-resonant induction heating are provided. In particular, a method for evaluating a switching duration for zero-voltage switching of a quasi-resonant inverter in an induction cooktop can be provided. The quasi-resonant inverter can include a power supply circuit configured to supply a power signal to the induction heating coil. The quasi-resonant inverter can further include an induction heating coil configured to inductively heat a load with a magnetic field, a resonant capacitor connected to the induction heating coil and one or more switching elements.

Abstract: Systems and methods of quasi-resonant induction heating are provided. In particular, an induction heating system having quasi-resonant inverters in an induction cooktop for improved controllability of multi-channel quasi-resonant inverters. The inverter can include an induction heating coil configured to inductively heat a load with a magnetic field, and a power supply circuit configured to supply a power signal to the induction heating coil. The inverter can further include one or more switching elements. The inverter can further include a resonant capacitor coupled in parallel with the induction heating coil. The inverter can further include having separate rectifiers in each channel to improve controllability.

Abstract: Systems and methods for detecting appliance pump cavitation or dry state are provided. An exemplary appliance can include a current measurement circuit configured to provide a feedback signal that describes an inverter current drawn by an inverter providing three-phase power to the pump motor. A control unit of an appliance can detect pump cavitation and dry state by monitoring the feedback signal. Another exemplary appliance can include a motor speed detection circuit configured to provide a motor speed signal describing the speed of the pump motor. The control unit of the appliance can monitor variance in pump motor speed to detect pump dry state or cavitation. An exemplary method includes monitoring either an inverter current used by an inverter to drive a motor or a variance in a rotational speed of the motor.

Abstract: Compressors and methods for determining optimal parking positions for compressor pistons are provided. A method includes performing a current value evaluation for an initial time during operation of a motor of the compressor. Performing the current value evaluation includes measuring a motor current value at the time and comparing the motor current value to an existing optimal parking current value. Performing the current value evaluation further includes modifying the existing optimal parking current value to the motor current value when the motor current value exceeds or is equal to the existing optimal parking current value.

Abstract: Compressors and methods for determining optimal parking positions for compressor pistons are provided. A method includes performing a current value evaluation for an initial time during operation of a motor of the compressor. Performing the current value evaluation includes measuring a motor current value at the time and comparing the motor current value to an existing optimal parking current value. Performing the current value evaluation further includes modifying the existing optimal parking current value to the motor current value when the motor current value exceeds or is equal to the existing optimal parking current value.

Abstract: A method of braking a washing machine from an operational speed to a zero speed is provided (as well as a washing machine incorporating the method) for a washing machine driven by one of a synchronous or asynchronous motor. Upon receipt of a stop signal, collapsing the motor rotating magnetic fields are collapsed for a predefined time period. After the predefined time period, DC braking voltage is applied to the motor stator windings at a controlled ramp-up rate to a fixed amplitude to generate a controlled ramped braking torque on the motor. The braking torque is applied until the motor is stopped.

Abstract: Systems and methods for detecting appliance pump cavitation or dry state are provided. An exemplary appliance can include a current measurement circuit configured to provide a feedback signal that describes an inverter current drawn by an inverter providing three-phase power to the pump motor. A control unit of an appliance can detect pump cavitation and dry state by monitoring the feedback signal. Another exemplary appliance can include a motor speed detection circuit configured to provide a motor speed signal describing the speed of the pump motor. The control unit of the appliance can monitor variance in pump motor speed to detect pump dry state or cavitation. An exemplary method includes monitoring either an inverter current used by an inverter to drive a motor or a variance in a rotational speed of the motor.

Abstract: A dishwasher is provided having a wash chamber that is supplied with wash water by a water circulation pump assembly. The pump assembly has a motor, an inlet in fluid communication with a sump, and an outlet in fluid communication with the wash chamber. A macerator system is configured with the pump assembly and includes a filter screen disposed across the inlet and a chopper blade rotationally driven by the pump assembly at a defined axial distance upstream from the filter screen. The chopper blade is biased by materials in magnetic flux communication to the defined axial distance so as to maintain the defined distance in a running and stopped states of the pump assembly.

Abstract: A dishwasher is provided having a wash chamber that is supplied with wash water by a water circulation pump assembly. The pump assembly has a motor, an inlet in fluid communication with a sump, and an outlet in fluid communication with the wash chamber. A macerator system is configured with the pump assembly and includes a filter screen disposed across the inlet and a chopper blade rotationally driven by the pump assembly at a defined axial distance upstream from the filter screen. The chopper blade is biased by materials in magnetic flux communication to the defined axial distance so as to maintain the defined distance in a running and stopped states of the pump assembly.

Abstract: A method of braking a washing machine from an operational speed to a zero speed is provided (as well as a washing machine incorporating the method) for a washing machine driven by one of a synchronous or asynchronous motor. Upon receipt of a stop signal, collapsing the motor rotating magnetic fields are collapsed for a predefined time period. After the predefined time period, DC braking voltage is applied to the motor stator windings at a controlled ramp-up rate to a fixed amplitude to generate a controlled ramped braking torque on the motor. The braking torque is applied until the motor is stopped.

Abstract: A detection circuit includes a first power line, a first signal conditioning module operationally coupled to the first power line, a neutral line (N) operationally coupled to the first signal conditioning module, a second signal conditioning module operationally coupled to the first power line, a second power line operationally coupled to the second signal conditioning module, and an analog to digital (A/D) converter operationally coupled to the first and the second signal conditioning modules.