Abstract: An apparatus for determining angular positions of DC motor includes a capacitor connected in parallel with the DC motor. The current flowing through the capacitor, at any given time, is an AC ripple current responsive to a commutation event of the DC motor. The capacitor partially sources the motor current ripples during commutation and recharges itself during the off-commutation period. Since the number of commutation events per mechanical revolution is pre-determined once the DC motor is designed, the frequency of the AC ripple currents through the capacitor corresponds to the frequency of commutation, and thus a motor position of the DC motor.

Abstract: Available torque output from a battery-powered traction motor system in a vehicle is estimated, wherein the system includes a high-voltage battery coupled to a traction motor by an inverter, wherein the inverter is controlled in response to a torque/speed command within an inverter controller, and wherein the system further includes a DC-to-DC converter coupled to the high-voltage battery to provide a reduced voltage to charge a low-voltage battery. Battery operating conditions of the high-voltage battery are determined including available battery power and battery voltage. Traction motor operating conditions including a flux linkage and other electrical parameters are determined. The battery information including voltage, current, and internal resistance is transformed into synchronous coordinates. An available quadrature current corresponding to the maximum available torque is determined in response to the traction motor operating conditions and the battery voltage in the synchronous coordinates.

Abstract: A permanent magnet synchronous machine having a base speed is controlled in response to a d-axis current command Idse*. A torque command Te* is determined and an angular velocity &ohgr;r of the machine is sensed. A maximum torque per ampere value is calculated for producing the commanded torque Te* at speeds below the base speed. The angular velocity &ohgr;r is compared with the base speed. If the angular velocity &ohgr;r is less than the base speed, then the maximum torque per ampere value is employed as the d-axis current command Idse*. If the angular velocity &ohgr;r is greater than the base speed, then the maximum torque per ampere value adjusted by a field-weakening factor proportional to the angular velocity &ohgr;r is employed as the d-axis current command Idse*.

Abstract: A permanent magnet synchronous machine is controlled according to a d-axis current command Idse* and a q-axis current command Iqse* needed to achieve a desired response of the machine. An actual d-axis current Idse and an actual q-axis current Iqse are sensed and an angular velocity &ohgr;r of the machine is sensed. A d-axis voltage command Vdse* is determined using a first proportional-integral regulator responsive to a d-axis current error &Dgr;Id, a q-axis current error &Dgr;Iq, and the angular velocity &ohgr;r. The first proportional-integral regulator includes a first weighted higher order term comprising a product of a first weighting factor, the angular velocity &ohgr;r, and the q-axis current error &Dgr;Iq.

Abstract: A method for achieving torque control of a permanent magnet synchronous motor is provided where operating conditions of the motor are sensed and used in a lookup table to retrieve corresponding reference values for calculating the electric current commands from a torque command. A lookup table for control of a permanent magnet synchronous motor is also provided. The lookup table comprises an input for at least one reference operating condition, with an output value of a retrieval operating condition for each value of the reference operating conditions. A method for lookup table control of a permanent magnet synchronous motor is also provided where an inductance differential and an uncompensated magnetic flux linkage are computed with a lookup table and limited. These values are then used to calculate an estimated inductance and a magnetic flux linkage.

Abstract: A method for vector control of a permanent magnet motor is provided. A torque command is provided from an open-loop observer circuit, which is manipulated to produce an AC voltage command to be applied to a permanent magnet motor. Also provided is a method for utilizing an open-loop observer circuit apparatus. The open-loop observer circuit apparatus takes three-phase inverter pole voltages and uses them to estimate electrical parameters of the permanent magnet motor A method for calculating three-phase inverter pole voltages is also provided, as is used in the open-loop observer circuit. A plurality of voltages are multiplied by the DC bus voltage to calculate the three-phase inverter pole voltages. Finally, a method for estimating electrical parameters is provided, as used in the open-loop observer circuit. Synchronous reference magnetic fluxes and currents are calculated, and these values are used to estimate the electrical parameters.