Abstract: A motor driving device drives a motor having a plurality of windings corresponding to a plurality of phases. The motor driving device includes: a first inverter configured to include a plurality of first switching elements and connected to first stages of the plurality of windings; a second inverter configured to include a plurality of second switching elements and connected to second stages of the plurality of windings; and a controller configured to fix switching states of the second switching elements and switch the first switching elements to compose target voltage vectors if the motor is driven in an open end winding type by operating the first inverter and the second inverter in a space vector pulse width modulation mode.

Abstract: The technologies described and recited herein pertain to a permanent magnet motor having multiple voltage taps so that the motor may run in multiple configurations, e.g., a low-range and a high-range, and have multiple optimal operating points.

Abstract: An electric machine has at least two sub-machines, each having the same number of phases and being designed to generate a magnetic rotary field independently of one another to rotate the rotor. The machine has a power output stage for each sub-machine, each being designed to energize the sub-machines independently of one another. The machine also has at least one or only one control unit which is connected to the power output stages and is designed to generate a PWM signal in order to actuate the power output stages. The control unit is designed to generate the PWM signal for the sub-machines such that each of the PWM pulses for a sub-machine begins at a starting time of a PWM period and/or to generate the PWM pulses for another sub-machine such that each of the PWM pulses ends at an end time of the PWM period for the other sub-machine.

Abstract: To provide a rotary electric machine apparatus which can make the rotary electric machine output torque, and can change characteristics of a rotary electric machine according to change of the DC power voltage, even if failure occurs in one DC power source. A rotary electric machine apparatus (1) is provided with a power source switching mechanism (23) that switches between the DC power of low voltage and the DC power of high voltage; a winding connection switching mechanism (24) that switches interconnection of the plural-phase windings between a first winding connection state, and a second winding connection state in which an induced voltage constant of windings becomes lower than the first winding connection state; a inverter (12) provided with the switching devices; and a controller (25) that switches the power source switching mechanism (23), switches the winding connection switching mechanism (24), and controls on/off of the switching devices.

Abstract: A motor drive system can detect a misconnection. A motor drive system for driving a motor including a plurality of stator windings includes: an inverter that converts a DC voltage supplied from a DC voltage source into an AC voltage and applies the AC voltage to the motor; a connection switching device that is disposed between the inverter and the motor and can switch a connection state of the stator windings; and a controller that performs abnormality determination on a connection state of the connection switching device on the basis of a current value of a current flowing in each of the stator windings.

Abstract: A drive apparatus for an electric motor includes an inverter, an inverter substrate, a wire connection switching unit, a control unit, and an alternating-current wire electrically connected at one end to the inverter and at the other end to one end of the windings of an electric motor. The drive apparatus for an electric motor includes an alternating-current wire electrically connected at one end to the alternating-current wires and electrically connected at the other end to one end of the wire connection switching unit, and an alternating-current wire electrically connected at one end to the other end of the wire connection switching unit and electrically connected at the other end to the other end of the windings of the electric motor. The drive apparatus for an electric motor includes a noise suppression unit provided at least on the alternating-current wires to suppress noise that occurs in the alternating-current wire.

Abstract: An engine generator, including an engine having a piston reciprocating inside a cylinder, a generator unit having a three-phase winding, driven by the engine to generate power and operating as an engine starter motor during engine starting, a power converter circuit connected to the generator unit, a battery supplying power to the generator unit through the power converter circuit during engine starting, an engine speed detection unit detecting an engine speed, a connection switching unit switching a connection configuration of the winding to one of a wye-connection and a delta-connection, and a connection switching control unit controlling the connection switching unit to switch the connection configuration to the wye-connection when the engine speed is lower than a predetermined engine speed, and to switch the connection configuration to the delta-connection when the engine speed is equal to or higher than the predetermined engine speed, during engine starting.

Abstract: A multiple-phase electric machine provided with multiple inverter power circuits is described herein. The present multiple-phase electric machine aim at performing configuration changes while reducing the loss of torque when machines are switched between configurations. This is done by forming groups of phases defining machine portions that are powered by a separate inverter power circuit and by switching the machine portions separately with controlled switching devices.

Abstract: A motor control method comprises providing a machine comprising a plurality of windings, a rotor and a stator magnetically coupled to the rotor, coupling a plurality of power converters to the plurality of windings, configuring the plurality of power converters so as to adjust the number of poles of the machine in a low-stress operating mode according to a plurality of operating parameters and after a fault occurs in the machine, configuring the plurality of power converters such that the machine enters a fault tolerant operating mode.

Abstract: An engine generator, including a general purpose engine, an engine speed of the engine being variably controlled, a generator unit having a three-phase winding and driven by the engine to generate power, an inverter unit converting AC output from the generator unit to AC of a predetermined frequency to output to a load, a connection switching unit switching a connection configuration of the winding to one of a wye-connection and a delta-connection, a load detection unit detecting a size of the load, and a connection switching control unit controlling the connection switching unit to switch the connection configuration to the wye-connection when the size of the load is equal to or lower than a predetermined value, and to switch the connection configuration to the delta-connection when the size of the load is higher than the predetermined value.

Abstract: The present subject matter is directed to an electrical power circuit connected to a power grid and method of operating same. The electrical power circuit has a power converter electrically coupled to a generator, such as a doubly-fed induction generator, having a rotor and a stator. Thus, the method includes operating rotor connections of the rotor of the generator in a wye configuration during a first rotor speed operating range. Further, the method includes monitoring a rotor speed of the rotor of the generator. Thus, the method also includes transitioning the rotor connections of the rotor from the wye configuration to a delta configuration if the rotor speed changes to a second rotor speed operating range.

Abstract: A switching device, for a wye-delta switch in a multiphase motor each phase having one motor winding having a connection pair and contact device (CD), has an electromagnetic drive for drive axle movement between three axial positions, the CD having first and second motor winding connection contacts (MWCC), phase connection contact (PCC), and movable contact bridge (MCB) coupled to the drive axle and movable thereby into the three positions. In position-1, axially between positions-2/3, the MCB is open—no CC is connected to another CC by the MCB; in position-2, the MCB is in ‘wye’ contact position—the MCB connects the PCC to the first MWCC, and the second MWCC is connected to the second MWCC of all other CDs using the ‘wye’ coupled to the drive axle; and in position-3, the MCB is in a ‘delta’ contact position—the MCB connects the FCC to the first and second MWCC.

Abstract: A method of regenerative braking includes providing an electric motor including at least one stator and a rotor, a speed of the rotor, a motor controller that regulates a current level in the stator winding, a power inverter which controls an energy flow to the stator terminal, and an energy storage system (ESS) which exchanges energy with the motor. A battery management circuit is between the power inverter and the ESS, and a processor has an associated memory storing a regenerative braking (RB) algorithm. The RB algorithm during braking causes the motor controller to execute determining an RB torque value from the rotor speed that maximizes regenerative braking current, and the power inverter is used to redirect the RB current to maximize a power transfer from the motor to the ESS.

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 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 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: A method for controlling switching between a full winding control mode and a half winding control mode for a multi-phase electric machine. The machine includes a stator and a rotor, split stator windings for each phase of the machine, where each stator winding includes a first winding section and a second winding section, an inverter circuit including a pair of inverter switches for each phase of the machine, where the pair of inverter switches for each phase is electrically coupled to the first and second winding sections for that phase, and a plurality of switch assemblies for switching between the full winding mode and the half winding mode, where each switch assembly is electrically coupled to the pair of inverter switches and the first and second winding sections for a particular phase, and where each switch assembly includes a first AC switching device and a second AC switching device.

Abstract: The present disclosure relates to an apparatus for the generation of a unidirectional electrical signal. The apparatus may include at least one magnet defining a magnetic field, a rotor disc of substantially no magnetic permeability comprising at least one magnetic field interrupter of magnetically permeable material positioned at a first radial distance from a center axis of the rotor disc, the rotor positioned so as to, upon rotation of the rotor disc, cause the at least one interruptor to pass through the magnetic field, and an electrical conductor extending across the magnetic field, whereby as the at least one interrupter passes through the magnetic field, the magnetic field is distorted by the interrupter thereby inducing a unidirectional electric signal in the conductor. The at least one magnet may be an electromagnet or a permanent magnet. The at least one magnetic field interrupter may be made of soft iron.

Abstract: Provided is an inverter apparatus 20 configured to switch a current winding to an optimal winding when a rotation speed of a rotor of an AC electric motor 40 is within a hysteresis region defined by first and second switch timings for switching a state of an armature winding between a first winding and a second winding and when the current winding differs from the optimal winding.

Abstract: Embodiments of the invention provide a starter machine including a housing. A motor can be positioned within the housing and coupled to a gear train, which can be coupled to a shaft. A switched reluctance solenoid assembly can be positioned within the housing and capable of being coupled to inverters that communicate with an electronic control unit. The switched reluctance solenoid assembly includes at least two switched reluctance stator assemblies and a rotor that is coupled to the shaft. The rotor can also include an integral pinion and is movably positioned within the switched reluctance stator assemblies. The rotor is capable of linear and rotational movement.

Abstract: Dynamic reconfiguration-switching of motor windings in a disk drive is optimized between winding-configurations by selectively lowering resistance of a constantly used portion of one of the motor windings. Acceleration is traded off in favor of higher velocity upon detecting the electric motor in the electric vehicle is at an optimal angular-velocity for switching to an optimal lower torque constant and voltage constant. The total back electromotive force (BEMF) is prohibited from inhibiting further acceleration to a higher angular-velocity.

Abstract: An apparatus for controlling an electric motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the electric motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the electric motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

Abstract: Dynamic reconfiguration-switching of motor windings in a motor is optimized between winding-configurations by selectively lowering resistance of a constantly used portion of one of the motor windings. Acceleration is traded off in favor of higher velocity upon detecting the electric motor in the electric vehicle is at an optimal angular-velocity for switching to an optimal lower torque constant and voltage constant. The total back electromotive force (BEMF) is prohibited from inhibiting further acceleration to a higher angular-velocity.

Abstract: A motor drive PWM rectifier includes a control section which generates the PWM signal in accordance with either a three-phase modulation scheme or a two-phase modulation scheme in which a PWM voltage command for one phase selected from among three phases each constituting the PWM voltage command in the three-phase modulation scheme is set and held at a level equivalent to a maximum value or minimum value of the PWM carrier and in which a PWM voltage command for the other two phases created by also applying an offset, required to achieve the setting, to the other two phases, a detecting section which detects three-phase AC current and outputs a detected current value, and a selecting section which selects the two-phase modulation scheme when the detected current value is larger than a first threshold value but smaller than a second threshold value, and otherwise selects the three-phase modulation scheme.

Abstract: A method of controlling operation of a multi-phase induction motor may include transmitting a low-speed operation signal by a master computer to a control signal board for low-speed operation of the motor; the control signal board receiving the low-speed operation signal, and in response to the low-speed operation signal, the control signal board sensing that the master computer is not simultaneously transmitting a high-speed operation signal, and in response to receiving the low-speed operation signal and not simultaneously receiving the high-speed operation signal, closing contactors in a power section to transmit power to the motor for low-speed operation, whereby the motor is connected to a source of multi-phase power and operates at low-speed; and the control signal board transmitting a first feedback signal to the master computer that the motor is connected to the source of multi-phase power and is running at low speed.

Abstract: A mining vehicle and a method of operating a mining vehicle. The mining vehicle includes a three or more phase electric drive motor. A nominal power of the drive motor is determined on the basis of a certain drive speed and load, whereby the drive motor has a nominal torque at a certain rotating speed. The drive motor is connected to a traction wheel of the mining vehicle using a fixed gear ratio. The rotation speed of the drive motor is controlled by using a motor controller. That drive motor is operated in a delta connection on the certain drive speed and when necessary the torque of the drive motor at a drive speed lower than the certain drive speed is increased by operating the drive motor in a star connection and simultaneously temporarily overloading the drive motor.

Abstract: A method for controlling operation of a multi-phase induction motor may include transmitting a high-speed operation signal by a master computer for high-speed operation of the motor; receiving the signal by a control signal board, and in response to the signal, the control signal board may sense that the master computer is not simultaneously transmitting a low-speed operation signal, and in response to receiving the high-speed operation signal and not simultaneously receiving the low-speed operation signal, closing delta-to-wye contactors and closing contactors in a power section to transmit power to the motor for high-speed operation, whereby the motor is connected to a source of multi-phase power and operates at high-speed; and the control signal board transmitting a first feedback signal to the master computer that the motor is connected to the source of multi-phase power and is running at high speed.

Abstract: A star-delta multi-level starter is provided for controlling a starting and a slow stopping of an AC induction motor with desired quality, nevertheless changing conditions of a power supplying and a motor charge. An improving of a quality of the starting or the stopping is achieved as a result of an increasing number of power levels from two achieved in usual star-delta starter and producing effective changing of the power levels. The increasing number of the power levels is achieved by using electrical elements, such as resistors, transformers and others. The changing of the power levels is fulfilled at moments defined automatically. The changing, of the power levels may be fulfilled in any predetermined order, for example, in step-by-step increasing or decreasing order. The control system of the star-delta multi-level starter permits to use one parameter for changing desired quality of the starting, as in usual star-delta starters.

Abstract: A winding switching apparatus includes a winding switching device and a drive circuit. The winding switching device is configured to switch a plurality of windings of an AC motor. The drive circuit is configured to control the winding switching device. The winding switching device includes a winding switch, a diode bridge, and a capacitor. The diode bridge includes a positive-side DC output terminal, a negative-side DC output terminal, and AC input terminals. The AC input terminals corresponds to respective phases of the AC motor. The positive-side and negative-side DC output terminals are respectively connected to positive-side and negative-side DC buses provided in an inverter. The AC input terminals are respectively connected to winding-switching terminals corresponding to the respective phases of the AC motor. The AC input terminals are respectively connected to phase terminals provided in the winding switch.

Abstract: A method and system for controlling operation of a multi-phase induction motor may include the steps of transmitting a signal by a master computer to actuate a first switch for high-speed or low speed operation of the motor, receiving the signal by a control signal board, and in response to the signal, the control signal board may determine that the motor is enabled for high-speed operation and disabled for low-speed operation, or enabled for low-speed operation and disabled for high-speed operation, as the case may be. In response to the motor state, the control signal board may close or open delta-to-wye contactors, then transmit a signal to a power section to close power contactors to connect the motor to a source of multi-phase power.

Abstract: A method and a system for controlling an asynchronous electric motor for detecting cabling errors between the electric motor and a motor starter. The electric motor including three windings distributed over three branches in a delta configuration and controlled by the motor starter, which includes power semiconductors directly connected in series within the three branches of the delta configuration of the three windings. In one embodiment, the method includes applying a voltage in a first branch of the delta, priming the semiconductor of the first branch after a priming delay, measuring an electrical current generated within the first branch during the priming, and determining the configuration of the cabling of the first branch according to the measured electrical current.

Abstract: An alternating current motor control system constituted of: a control unit; a current monitor in communication with the control unit, the current monitor arranged to provide an indication of the amount of current flowing through at least two windings of a target alternating current motor; and a semiconductor switching unit arranged to connect the windings of the target alternating current motor to a three phase power input in one of a star and a delta configuration responsive to the control unit, wherein the control unit is arranged to alternately connect the winding of the target alternating current motor in one of a star and a delta configuration responsive to a predetermined condition of the amount of current flowing through the at least two windings of the target alternating current motor.

Abstract: In a motor-generator control system for controlling a motor-generator, first and second sets of multiphase windings of a motor-generator are arranged to be spatially shifted in phase from each other. An allocating unit is configured to, upon input of workload request for the motor-generator, determine a first torque to be allocated to the first set of multiphase windings and a second torque to be allocated to the second set of multiphase windings. A resultant torque of the first torque and second torque meets the input workload request for the motor-generator. An energizing unit is configured to energize the first set of multiphase windings to create the first torque and energize the second set of multiphase windings to create the second torque.

Abstract: A power tool having an electronically commutated DC motor capable of providing various operating modes ranging from a maximum efficiency operating mode to a maximum power operating mode. The motor has a rotor having permanent magnets mounted in recesses in a back iron of the rotor. In one embodiment the motor has three phase windings, each having at least a pair of coils. The phase windings are connected in either a delta or a wye configuration via electromechanical or electronic switching components, or a combination of both, by a controller within the tool. The coils in each phase winding can also be switched between series and parallel configurations to configure the motor to provide its various operating modes. In one embodiment a dual wound motor is disclosed that has its phase coils dynamically or statically switchable between series and parallel configurations.

Abstract: The present invention relates to a six-phase generator for a motor vehicle having two three-phase systems displaced with respect to one another by 30°, the phase windings of one of the three-phase systems being positioned in a wye connection and the phase windings of the other three-phase system being positioned in a delta connection.

Abstract: This invention relates to low loss power supply system comprising a rectifying bridge (3) supplying current to a motor, wherein the rectifying bridge including two AC power feed inputs PA, PB as well as at least one output for supplying power to said motor M, and wherein an YD transformer (2) is coupled between said inputs, said YD transformer, comprising a star and delta winding, and being adapted to provide an approximately 30° phase shift relative to the chosen fundamental frequency between said inputs.

Abstract: Systems and apparatus are provided for an inverter system for use in a vehicle having a first energy source and a second energy source. The inverter system comprises an electric motor having a first set of windings and a second set of windings. The inverter system further comprises a first inverter coupled to the first energy source and adapted to drive the electric motor, wherein the first set of windings are coupled to the first inverter. The inverter system also comprises a second inverter coupled to the second energy source and adapted to drive the electric motor, wherein the second set of windings are coupled to the second inverter. A controller is coupled to the first inverter and the second inverter to achieve desired power flow between the first energy source, the second energy source, and the electric motor.

Abstract: A method of starting and apparatus for starting a multiphase electrical machine is disclosed. The aim is to reduce oscillatory pulsation in torque generated by the motor and inrush current that occurs shortly after start-up. The starting method comprises the steps of first connecting at least one, but less than all, of a plurality of windings to a respective phase-shifted supply voltage at a controlled point in the supply phase. Then, after a controlled delay following the connection made in step i., connecting the or each remaining winding of the machine a respective phase-shifted supply voltage. The invention has particular application to multiphase (most usually, 3-phase) motors. However, it can also be applied to other electrical machines, such as generators and transformers. The method can be performed at initial start-up or, in the case of application to a motor, at Y-delta switchover. On reconnection of a load generating a significant back-e.m.f., the 2-step process is initiated when the back-e.m.f.

Abstract: The present invention is an electrical rotating apparatus comprising stator coils wound around the inside and outside of the stator. In a further embodiment, the machine contains a high number of phases, greater than three. In a further embodiment, the phases are connected in a mesh connection. In a further embodiment, each half-phase is independently driven to enable second harmonic drive for an impedance effect. Improvements are apparent in efficiency and packing density.

Abstract: A circuit for controlling a brushless permanent magnet motor is provided. The circuit comprises windings, each of the windings having a first end connected at a common node and each of the windings having a second end connectable directly to supply voltages by switches, the second end connected to an upper supply voltage or connected to a lower supply voltage or disconnected from the supply voltages; blocking circuitry connectable with the second ends, the blocking circuitry producing a blocked voltage; a comparator receiving the blocked voltage on one input and a reference voltage on another input, the comparator result indicating polarity of a back emf voltage in the associated winding; and a latch providing control signals for the circuit, an input of the latch enabled by an enable signal, an output of the latch comprising a back emf voltage detection signal. The blocking circuitry and the comparator are duplicated for each of the windings.

Abstract: Systems and methods are provided for dynamically changing configurations of multi-inverter drive systems. By changing configurations during operation, a multi-inverter system of the present invention can provide greater than half of full output power during failure of a power cell and can provide efficient braking torque during regeneration. The inverter drive system includes a plurality of single pole inverter cells and a configuration switch system connecting the single pole inverter cells in a star configuration and for changing the connection configuration of the single pole inverter cells. In one embodiment, the configuration switch system is adapted to dynamically change the star configuration of the inverter system to a mesh configuration during operation of the load. In another embodiment, the configuration switch system is adapted to dynamically change the star configuration of the single pole inverter cells to form a polyphase inverter.

Abstract: A method for controlling voltages in an integrated starter alternator electric machine is provided where the armature windings are manipulated in a ?/Y/? fashion. In particular, the armature windings are arranged in a ? connection during engine cranking operation, when the electric machine acts as a starter motor. After the engine is cranked, the windings are changed into a Y connection when the ISAD machine changes from motoring to generating and operates a low speeds, such as idle speed. Next, when the engine speed increases above a predetermined winding reconfiguration speed, the windings are switched from Y to ? connection. If the engine speed falls below the winding reconfiguration speed, the machine again switches the armature windings to a Y connection to take advantage of the efficiencies of the Y connection at that low speed range in the generating state.

Abstract: It is an object to provide a winding switching device of a three-phase AC motor having a small size at a low cost in which a time required for switching a winding is shortened and the number of semiconductor switch units is decreased as much as possible.

Abstract: Significantly increased torque is provided from a motor having a stator with a core and at least two three-phase windings wound on the core. The two windings are separated spatially by 30 electrical degrees. Power is provided to the two windings by two power supplies which each provide power at the same fundamental frequency and with a component at the third harmonic of the fundamental, with the power provided from one power supply shifted in time by 30° of the fundamental frequency with respect to the power provided by the other power supply. The additional third harmonic component reduces the effective peak flux density, allowing an increase in the fundamental component of flux to allow an increase in effective torque, with the third harmonic component also providing additional torque.

Abstract: A system includes a motor mounted within a housing and a compressor pump unit. A single-phase PSC motor includes a switch assembly which selectively connects primary or alternate windings. During normal load operation, when maximum efficiency is desired, the switch is placed in one position, then during high load operation, when maximum torque output is needed at maximum a load point, the switch is placed in the closed position. In effect, the number of main winding turns is decreased and the motor is strengthened. As the auxiliary capacitors are also now connected in parallel, the net effect is an increase in the total auxiliary capacitance, which also serves to strengthen the motor. Another embodiment provides a switch for a three-phase WYE connected motor. In yet another embodiment, a three phase delta connected motor switch is provided.

Abstract: A method of operating an electric three-phase machine with a polyphase winding arrangement in a vehicle. The phases of the winding arrangement are connected to a vehicle network with the aid of power converters and the winding arrangements are interconnected in a first method of connection for motor operation and interconnected in a second method of connection for generator operation. Switching over from one method of connection to the other is performed at an instant at which the three-phase machine changes from the state of picking up torque to outputting torque, or from the state of outputting torque to picking up torque.

Abstract: A system includes a motor mounted within a housing and a compressor pump unit. A single-phase PSC motor includes a switch assembly which selectively connects primary or alternate windings. During normal load operation, when maximum efficiency is desired, the switch is placed in one position, then during high load operation, when maximum torque output is needed at maximum a load point, the switch is placed in the closed position. In effect, the number of main winding turns is decreased and the motor is strengthened. As the auxiliary capacitors are also now connected in parallel, the net effect is an increase in the total auxiliary capacitance, which also serves to strengthen the motor. Another embodiment provides a switch for a three-phase WYE connected motor. In yet another embodiment, a three phase delta connected motor switch is provided.

Abstract: A method for detecting a zero-cross event of an induced back electromotive force (BEMF) or of a nullification instant of a periodic current in a PWM driven winding, by circuits generating an analog signal representative of the induced BEMF or of the nullification instant of the periodic current, comparing the analog signal with zero and producing a first logic signal, generating a PWM driving signal, and storing a time between two consecutive zero-cross events, is provided. The method may include storing a time between a last two zero-cross events and synchronizing the PWM driving signal from a last zero-cross event having a duration equal to a difference between an established time based upon the stored time interval and a first time. If a new zero-cross event is not detected within the established time, switching of the PWM driving signal may be disabled for a time having a maximum duration equal to a second time or until a new zero-cross event is detected.

Abstract: A method is provided for driving a brushless motor of a type including windings pre-connected in a star or polygon configuration with an integrated driving system designed for independently driving the phase windings. The integrated driving system includes a plurality of output pins corresponding to the output nodes of as many half-bridge stages that are driven in pairs respectively by a direct or inverted driving signal at the same power level without overloading the output metal lines of the integrated device. Each supply terminal of the brushless motor is connected to one of the plurality of output pins of the integrated system relative to a first driving phase signal and to another output pin relative to a different driving phase signal. The drive circuit is internally configured through a plurality of integrated signal path selectors set in one or the other position depending upon the intended use of the integrated device.

Abstract: An improved induction motor having at least one capacitive element electrically connected in parallel with and tapped to each phase of a delta- or wye-wound stator winding such that the capacitive elements are alternately charged or discharged during operation, thereby storing energy from and releasing energy to the windings. This alternate energy storage and release assists in controlling the level of magnetic core saturation and increasing motor efficiency under all operating conditions due to reduced hysteresis and eddy current losses. Motor starting or inrush current is also substantially reduced using this arrangement. In one embodiment, variable capacitors and switch elements are used to provide the ability to dynamically “tune” the motor winding for optimal efficiency.