Abstract: An apparatus for controlling an AC power supply for an electric motor, said AC power supply being derived from a DC voltage. The apparatus comprises a comparer configured to provide a comparison of a modulation index of a motor control signal with a reference value. This current data provider is configured to provide current data based on a torque demand signal; a speed signal indicating the speed of rotation of the AC motor; and an indication of the DC voltage modified on the comparison for control of the motor control signal which is based on the motor current data.

Abstract: A comminuting machine includes a frame, a comminuting rotor coupled to the frame, and a rotary drive coupled to the rotor. The rotary drive including a controller, a multi-phase motor connected to the controller, a set of contactors disposed between the controller and the multi-phase motor for selectively providing driving motive force to the multi-phase motor, and at least one rheostat disposed between the controller and the multi-phase motor, in parallel with the first set of contactors, for selectively providing a stopping resistance to the multi-phase motor to effect frictionless braking of the comminuting rotor, wherein the controller is configured to operate the set of contactors and the at least one rheostat to single phase lines of the multi-phase motor for providing the stopping resistance.

Abstract: A system and method for dynamically optimizing flux levels in electric motors based on estimated torque. Motor parameters and motor equations are used to estimate operating characteristics and to set current and voltage limits which define an optimal flux operating range for a given speed and torque of the motor. A slope of a linear flux gain is determined within the defined operating range at different speeds of the motor. The determined slopes for the different speeds are saved in a memory element. A control element determines and achieves an optimal flux level for the motor by accessing the table to identify a specific slope which corresponds to an actual speed of the motor, multiplying the slope by the estimated torque and adding an offset value to determine a phase current component value associated with the optimal flux level, and applying the determined phase current component value to the motor.

Abstract: When the current flowing through each electric terminal of an AC motor 21 reaches the vicinity of zero, an operation putting the electric terminals of the AC motor 21 into an opened state, or putting an electric terminal into a conductive state via a reflux diode inside an inverter 11, is carried out. Herein, as an operation such that the current flowing through each electric terminal reaches the vicinity of zero, the electric terminals are short-circuited by all upper arm or lower arm switching elements of the inverter 11 being turned on. By so doing, a flow of electromagnetic energy of a reactance component of the AC motor 21, from the AC motor 21 into the inverter 11 side when the drive of the inverter 11 is stopped, is prevented or suppressed. As a result of this, an overvoltage or overcurrent is prevented.

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 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: This invention concerns an electric drive system (200) for driving an output. The electric drive system comprises: a first electric motor (250) arranged to drive a first input shaft (230) at a first angular velocity, ?1, and a second electric motor (260) arranged to drive a second input shaft (240) at a second angular velocity, ?2. A gear mechanism (210) is provided and is arranged to transmit angular rotation of the first (230) and second (240) input shafts to drive the output (220) at an output angular velocity, ?out, such that ?out is proportional to a?1-b?2, where a and b are constants. The electric drive system (200) further comprises a controller (270) arranged to control operation of the first (250) and second (260) electric motors. When the output (220) is to be driven from ?out=0, the controller (270) is arranged to control the first (250) and second (260) electric motors to drive the first (230) and second (240) input shafts.

Abstract: A protection system for an electrical variable speed doubly fed induction machine having a stator and a rotor, comprising: instrument transformers capable of measuring low frequency signals from the rotor and stator, in particular low frequency signals in the range of 0.1 Hz to 6 Hz; a protection relay which is configured to receive measurement values from the instrument transformers and to sample said measurements values at a constant sampling rate.

Abstract: A method for field-oriented control of a frequency converter for a three-phase motor includes the setting of a new position of the rotary field in the electric motor being performed by voltage pulses for the stator coils. An amplitude and the angle of the rotary field vector are specified by the duration of the voltage pulses for the respective coils and by their temporal offset. The duration and the offset of voltage pulses for the stator coils are the result of the calculation of manipulated variables in a digitally controlled process in a coordinate system fixed in respect of the rotor, depending on the prevailing angular rotation (theta) and the prevailing speed of rotation (omega) as well as on the prevailing current values, a predetermined torque and a predetermined speed of rotation.

Abstract: One embodiment describes a motor starter including 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 that opens to disconnect power from a second winding of the motor; a fourth single pole switching device that closes after the third single pole switching device opens to connect power to the second winding; a fifth single pole switching device that opens to disconnect power form a third winding of the motor; and a sixth single pole switching device closes after the fifth single pole switching device opens to connect power to the third winding.

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: A motor control apparatus includes a high-resolution encoder for position control and a low-resolution encoder for velocity control, position control means for generating a velocity command in accordance with a difference between a given position command and the output of the high-resolution encoder, and velocity control means for generating a current command in accordance with a difference between the velocity command and a detected velocity that is based upon the output of the low-resolution encoder. A velocity control cycle based upon the velocity control means is made faster than a position control cycle based upon the position control means.

Abstract: An AC motor drive motor system includes a charge and discharge controller controlling a charging and discharging circuit based on a DC voltage value on the output side of a converter and a charging and discharging current value of a power storage device. The charge and discharge controller, when regenerative power via an inverter from an AC motor exceeds a power threshold, charges the power storage device such that the DC voltage value becomes a voltage threshold corresponding to the power threshold. When regenerative power is the power threshold or less, the converter performs regeneration when the DC voltage value reaches a regeneration start voltage threshold or higher, and ends regeneration when the DC voltage value reaches a regeneration end voltage threshold or lower. The DC-voltage-value time averaged value during regeneration is set lower than that at no-load time when the converter does not perform power supply and regeneration.

Abstract: In some embodiments, a motor drive system includes a communication subassembly electrically coupled to a control subassembly for providing communication between the control subassembly and at least one external device. The control subassembly and the communication subassembly transmit and receive control data independently of messaging data, greatly enhancing performance and reducing the workload of processors on the control subassembly and communication subassembly. Additionally, the control subassembly and the communication subassembly transmit message data via sequence count based messaging. Communications between the communication subassembly and the control subassembly may include a series of timeout periods and retries, increasing reliability.

Abstract: A motor drive system includes a control module and a power module for generating control signals and power signals, respectively, for driving an electric motor. An add-on module or subassembly is physically positionable between the control and power modules, and communicates with the control module to allow for communication with external devices.

Abstract: One embodiment describes a method that includes determining a desired torque level of a motor actuated by a motor starter; determining, using a control system, a configuration of the motor starter to achieve the desired torque level, in which determining the configuration includes determining which of a plurality of switching devices in the motor starter should be opened and which should be closed; and instructing, using the control system, the motor starter to implement the determined configuration by opening or closing one or more of the plurality of switching devices.

Abstract: In a power supply system using various kinds of storage batteries such as a large capacity storage battery or a small capacity storage battery, an electric power path is complicated, which may increase failures such as a short circuit trouble. There is a problem in that, when a short circuit trouble between storage batteries occurs, damage to a smaller capacity storage battery is serious. Accordingly, in a power supply system according to the present invention, the relationship among voltages, current capacities, and electric power capacities of various kinds of storage batteries such as a large capacity storage battery or a small capacity storage battery is defined so that damage to the storage batteries may be minimized even when malfunction occurs in, for example, switching a switch, and energy transfers from a higher voltage storage device.

Abstract: A cleaning system including a body; a motor; a switch; an unit removable from the body; and a power reset device. The switch configured to provide power to the motor upon receiving a first input, and prohibit power to the motor upon receiving a second input. The power reset device configured to prohibit power to the motor upon removal of the removable unit from the body, and provide power to the motor upon replacement of the removable unit onto the body and the switch receiving a third input.

Abstract: A blower motor assembly having a variable speed motor that is suitable for replacing a PSC motor in a residential HVAC (heating, ventilation, and air conditioning) system. The blower motor assembly includes a variable speed motor and motor controller; a first power input for receiving a plurality of AC power signals from a control device for use in determining an operating parameter for the motor; and a second power input for receiving AC power from an AC power source for powering the motor controller even when no AC power signals are received by the first power input.

Abstract: A power source system provides: an electrical generator including a rectifying circuit configured by one or more rectifying diodes for allowing electric conduction from a ground side to a battery side; a fuse arranged between the electrical generator and a battery; and a driving apparatus including a circuit configured by one or more semiconductor elements having one or more parasitic diodes for allowing electrical conduction from the ground side to the battery side, and a load. The number of parasitic diodes to be connected in series between a ground and the fuse in the driving apparatus is larger than the number of rectifying diodes to be connected in series between the ground and the battery side in the electrical generator. In addition, the circuit switches electrical conduction in the load.