Abstract: An elevator drive system (40) includes a permanent magnet (PM) synchronous electric motor (34) including a plurality of phases and a plurality of motor drives (55, 58) electrically connected to the PM synchronous electric motor. Each of the plurality of motor drives is operatively connected to a corresponding one of the plurality of phases. The plurality of motor drives is configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases.

Abstract: A permanent magnet (PM) synchronous electric motor (34) includes a plurality of phases, and a plurality of motor drives (55,58) electrically connected to the PM synchronous electric motor. Each of the motor drives is operatively connected to a corresponding one of the plurality of phases. The plurality of motor drives is configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases. A controller (44) is operatively connected to each of the plurality of motor drives to selectively control the PM synchronous electric motor, and a rescue module (120) operatively connected to the controller, the rescue module being configured and disposed to determine a failure of one of the plurality of motor drives and control the PM synchronous electric motor in a reduced operation profile employing remaining ones of the plurality of motor drives.

Abstract: A permanent magnet (PM) synchronous electric motor(34) includes a plurality of phases, and a plurality of motor drives(55,58) electrically connected to the PM synchronous electric motor. Each of the motor drives is operatively connected to a corresponding one of the plurality of phases. The plurality of motor drives is configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases. A controller(44) is operatively connected to each of the plurality of motor drives to selectively control the PM synchronous electric motor, and a rescue module(120) operatively connected to the controller, the rescue module being configured and disposed to determine a failure of one of the plurality of motor drives and control the PM synchronous electric motor in a reduced operation profile employing remaining ones of the plurality of motor drives.

Abstract: An elevator drive system (40) includes a permanent magnet (PM) synchronous electric motor (34) including a plurality of phases and a plurality of motor drives (55, 58) electrically connected to the PM synchronous electric motor. Each of the plurality of motor drives is operatively connected to a corresponding one of the plurality of phases. The plurality of motor drives is configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases.

Abstract: A hoist motor (12) for an elevator (14) is continuously driven from an irregular power supply (16). A regenerative drive (10) delivers power between the power supply (16) and the hoist motor (12). A controller (11) measures a power supply voltage in response to a detected change in the power supply voltage and controls the regenerative drive (10) to adjust a nominal motion profile of the elevator (14) in proportion with an adjustment ratio of the measured power supply voltage to a normal power supply voltage.

Abstract: An encoder failure in an elevator drive system is detected and managed. A velocity of the elevator drive system is provided by an encoder signal (60) and compared with a minimum velocity threshold (62). An encoder fault timer is incremented when the velocity is less than the minimum velocity threshold (64). The elevator drive system is disabled when the encoder fault timer reaches a fault threshold time (66).

Abstract: A hoist motor (12) for an elevator (14) is continuously driven from an irregular power supply (16). A regenerative drive (10) delivers power between the power supply (16) and the hoist motor (12). A controller (11) measures a power supply voltage in response to a detected change in the power supply voltage and controls the regenerative drive (10) to adjust a nominal motion profile of the elevator (14) in proportion with an adjustment ratio of the measured power supply voltage to a normal power supply voltage.

Abstract: An encoder failure in an elevator drive system is detected and managed. A velocity of the elevator drive system is provided by an encoder signal (60) and compared with a minimum velocity threshold (62). An encoder fault timer is incremented when the velocity is less than the minimum velocity threshold (64). The elevator drive system is disabled when the encoder fault timer reaches a fault threshold time (66).

Abstract: The temperature (25, 33, 43) of solid state switching devices in variable speed motor drives (11, 18), such as elevator motor drives, are utilized to reduce the load on the drive, by reducing the switching frequency (50) or the commanded load (110). The choice between the preferred non-switching zero state and an alternative zero state is determined (60) by temperature (28, 34, 56) of the switched transistor's anti-parallel diode. The rate of recognizing reduced temperatures is limited (33, 34) to avoid motor speed and/or load variations. The temperature may either be measured (24, 27) or determined (70) from models utilizing manufacturer product specification and normalized thermal transient response from the transistor/diode package to a heat sink.

Abstract: In a pulse width modulation-controlled, switched bridge, DC converter, the phase angle (44, 45) of the AC mains (4) is provided without sensing the voltage thereof, by a phase-locked loop (47) having one input (75) derived (126) from the in-phase voltage command Vde* (61) and another finit (77) approximating the line frequency; the phase-locked loop is initialized at a phase angle &thgr;init(76) equal to the arctangent (124) of the in-phase Vdest, and quadrature Vqest representation of estimated line voltages ere, ese, ete (119-121) derived during an initialization cycle from reconstruction of the fundamental component of the AC main currents at a phase angle (93) changing with said frequency. Reconstruction includes providing the discrete Fourier transform (DFT, 81) of signals indicative of currents (37) in the AC mains and the inverse DFT (122) of the resultant Fourier coefficients eia, eib.