Abstract: A system includes a motor, an inverter bridge, a voltage detection circuit, and a controller. The motor has a stator and a rotor. The inverter bridge is configured to provide a voltage to the stator, and includes a first switch connected in a series-type relationship with a second switch, a first diode coupled across the first switch, and a second diode coupled across the second switch. The voltage detection circuit is configured to detect a back EMF voltage in the winding. The controller is configured to control the first switch and the second switch to drive the motor, and to receive an indication of the back EMF voltage in the winding from the voltage detection circuit. The controller is also configured to determine a fault has occurred, and to drive one of the first switch and the second switch when a fault has occurred.

Abstract: A system includes a motor, an inverter bridge, a voltage detection circuit, and a controller. The motor has a stator and a rotor. The inverter bridge is configured to provide a voltage to the stator, and includes a first switch connected in a series-type relationship with a second switch, a first diode coupled across the first switch, and a second diode coupled across the second switch. The voltage detection circuit is configured to detect a back EMF voltage in the winding. The controller is configured to control the first switch and the second switch to drive the motor, and to receive an indication of the back EMF voltage in the winding from the voltage detection circuit. The controller is also configured to determine a fault has occurred, and to drive one of the first switch and the second switch when a fault has occurred.

Abstract: A system includes a motor, an inverter bridge, a voltage detection circuit, and a controller. The motor has a stator and a rotor. The inverter bridge is configured to provide a voltage to the stator, and includes a first switch connected in a series-type relationship with a second switch, a first diode coupled across the first switch, and a second diode coupled across the second switch. The voltage detection circuit is configured to detect a back EMF voltage in the winding. The controller is configured to control the first switch and the second switch to drive the motor, and to receive an indication of the back EMF voltage in the winding from the voltage detection circuit. The controller is also configured to determine a fault has occurred, and to drive one of the first switch and the second switch when a fault has occurred.

Abstract: A system for operating a compressor. The system includes a motor, an inverter bridge, a voltage detection circuit, and a controller. The motor has a stator and a rotor. The inverter bridge is configured to provide a voltage to the stator, and includes a first switch connected in a series-type relationship with a second switch, a first diode coupled across the first switch, and a second diode coupled across the second switch. The voltage detection circuit is configured to detect a back EMF voltage in the winding. The controller is coupled to the inverter bridge and the voltage detection circuit. The controller is configured to control the first switch and the second switch to drive the motor, and to receive an indication of the back EMF voltage in the winding from the voltage detection circuit. The controller is also configured to determine a fault has occurred, and to drive one of the first switch and the second switch when a fault has occurred.

Abstract: A system including an induction machine with a toroidally wound stator and a squirrel cage rotor is presented. The toroidally wound stator has a plurality of phase windings. A position sensor may be operatively connected to the induction machine for providing a position indication that is indicative of a relative position of the rotor and the stator. The system also includes an inverter having a plurality of solid-state switches and a control system. The inverter has the same number of phases as the toroidal induction machine. The inverter is connected to selectively energize the phase windings. A programmable microprocessor, such as a digital signal processor, is operatively connected to the induction machine and includes a program to implement vector control of the induction machine. The microprocessor can also control the inverter so that the induction machine operates with a predetermined number of poles using pole phase modulation.

Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a minimal number of current sensors and controlling at least one of a machine flux, an output voltage and generator torque, based on the stator or rotor flux magnitude and position. This method comprises measuring a plurality of current amounts; transforming them into a two phase reference system; measuring a DC voltage; measuring voltage amounts in the generator; transforming the plurality of voltage amounts into the two phase reference system; calculating a flux in the generator; comparing the calculated flux magnitude with a desired flux; determining a d-axis voltage; determining a desired torque amount; comparing the desired torque amount with an estimated torque amount; determining a q-axis voltage; and transforming the d-axis voltage and the q-axis voltage to stationary reference frame n-phase voltages using the position of the flux.

Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a minimal number of current sensors and controlling at least one of a machine flux, an output voltage and generator torque, based on the stator or rotor flux magnitude and position.

Abstract: A system including an induction machine with a toroidally wound stator and a squirrel cage rotor is presented. The toroidally wound stator has a plurality of phase windings. A position sensor may be operatively connected to the induction machine for providing a position indication that is indicative of a relative position of the rotor and the stator. The system also includes an inverter having a plurality of solid-state switches and a control system. The inverter has the same number of phases as the toroidal induction machine. The inverter is connected to selectively energize the phase windings. A programmable microprocessor, such as a digital signal processor, is operatively connected to the induction machine and includes a program to implement vector control of the induction machine. The microprocessor can also control the inverter so that the induction machine operates with a predetermined number of poles using pole phase modulation.

Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a plurality of flux sensing coils and controlling at least one of a machine flux and an output voltage based on the stator or rotor flux magnitude and position. One embodiment of the invention only uses flux sensing coils without requiring current sensors or position sensors.

Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a plurality of flux sensing coils and controlling at least one of a machine flux and an output voltage based on the stator or rotor flux magnitude and position. One embodiment of the invention only uses flux sensing coils without requiring current sensors or position sensors.

Abstract: The commutation circuit for commutating a conducting thyristor includes an inductance, a capacitance and a commutation thyristor all connected in series with the conducting thyristor and the dc source, the commutation thyristor initiates the commutation when triggered. The circuit further includes a first diode connected in reverse polarity across the commutation thyristor and a second diode connected in reverse polarity across the commutation thyristor-capacitance series circuit. The voltage across the capacitance is zero when each commutation cycle is initiated, and also when each commutation cycle ends.

Abstract: The inverter may be single phase with one inverter leg or N-phase with N inverter legs for connection across a DC source. Each leg includes a pair of series connected thyristors with a terminal between the thyristors for connection to a load. In addition, each thyristor has a diode connected in reverse polarity across it. A commutation circuit which includes an inductor in series with the inverter legs and a capacitor in parallel with the inductor and the inverter legs, provides a commutation pulse to turn off the thyristors in each leg. A further isolating inductor is connected at the DC power input to the inverter, and a reverse polarity feedback diode may be connected across it.

Abstract: The multilevel inverter includes a voltage divider which when connected across a dc source E.sub.D, provides voltage at terminals having values between +E.sub.D to -E.sub.D. A first and a second set of thyristors pairs are connected between the positive or negative terminals, respectively, and a load terminal for applying selected voltage levels to the load. Any thyristor pair in these sets may be turned-off by firing the thyristor pair at the next highest voltage level. However, the main thyristors which are connected to the +E.sub.D or -E.sub.D terminal is turned-off by a commutation circuit. This circuit includes a single capacitor maintained at zero voltage and subjected to an oscillating voltage during the commutation cycle to turn-off the conducting main thyristor. Such an inverter can easily provide a waveform having a series of pulses at one or more voltage levels thereby eliminating harmonics in the output.