A method for determining a stator current vector for starting a synchronous machine of a drive of a passenger transportation apparatus having a rotor and a stator with a stator winding may involve imposing different stator current vectors with different stator current vector directions on the stator winding over the course of a plurality of current application operations, determining from the different stator current vectors a minimum stator current vector with a minimum stator current vector direction at which a minimum driving torque acting on the rotor is generated in the synchronous machine, determining a starting stator current vector with a starting stator current vector direction from the minimum stator current vector, and imposing the starting stator current vector on the stator winding for starting the synchronous machine.

A method for identifying a position of a multi-phase brushless motor includes applying a plurality of detection voltage pulses to the motor, each detection voltage pulse corresponding to a respective driving phase of the motor, measuring a time period associated with a current reaching a predetermined current limit for each applied detection voltage pulse, and identifying a driving phase associated with a shortest time period for the current to reach the predetermined current limit.

A system and method for sensing rotor position of a three-phase permanent magnet synchronous motor (PMSM) includes a controller coupled with the PMSM and causing a plurality of voltage pulses to be applied thereto. A timer and/or an analog-to-digital converter is coupled with the PMSM and measures a plurality of values (measured values) from a three-phase inverter coupled with the PMSM. Each measured value may correspond with one of the plurality of voltage pulses and includes a current value or time value corresponding with an inductance of the PMSM. One or more logic elements calculates, based on the measured values and on one or more position algorithms, a position of a rotor of the PMSM relative to a stator of the PMSM. The system is configured to calculate the position of the rotor when the rotor is in a stopped configuration and when the rotor is in a rotating configuration.

A system and method for sensing rotor position of a three-phase permanent magnet synchronous motor (PMSM) includes a controller coupled with the PMSM and causing a plurality of voltage pulses to be applied thereto. A timer and/or an analog-to-digital converter is coupled with the PMSM and measures a plurality of values (measured values) from a three-phase inverter coupled with the PMSM. Each measured value may correspond with one of the plurality of voltage pulses and includes a current value or time value corresponding with an inductance of the PMSM. One or more logic elements calculates, based on the measured values and on one or more position algorithms, a position of a rotor of the PMSM relative to a stator of the PMSM. The system is configured to calculate the position of the rotor when the rotor is in a stopped configuration and when the rotor is in a rotating configuration.

A method for the diagnosis of the offset of the resolver of an electric motor, comprising acquiring a predetermined offset of a resolver associated with the electric motor; in a first transient, supplying an excitation current to the phases of the electric motor. As a consequence of the excitation current, a current established on the axis d of minimum reluctance and a current established on an axis q in phase quadrature with respect to the axis of minimum reluctance are determined. The correctness of the offset of the resolver is diagnosed if the current established on the axis d in the first transient is higher than the current established on the axis d in the second or third transient, and if the current established on the axis q in the first transient is lower than the current established on the axis q in the second or third transient.

A motor controller includes a square wave voltage generator and adding circuitry for adding the square wave voltage to a first drive voltage that is connectable to the stator windings of a motor. A current monitor for monitoring the input current to the motor as a result of the square wave voltage. A device for determining the position of the rotor based on the input current.

A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.

A variable speed drive comprises an output for delivering a drive voltage to an electric motor, power inverter, a drive controller, and a current sensor. The drive controller includes a PWM generator, a control law module, and a state variable estimator for estimating a state variable of the electric motor. The module computes a target voltage signal based on state variable estimates provided by the estimator and outputs the target voltage signal to the PWM generator. The generator approximates the target voltage signal with a PWM control signal, controls the inverter using the control signal, computes, based on the deviation between the control signal and the target voltage signal, an estimation support signal, and outputs the estimation support signal to the estimator. The estimator estimates a state variable of the motor based on the estimation support signal and the drive current, and outputs the estimate to the module.

An estimate of the initial position of a rotor is made by monitoring sensed motor current signals which are amplitude and phase modulated with the rotor flux position in response to a high frequency voltage signal injection. The motor current signals are envelope detected to determine zero crossing points. Samples are taken of the motor current signals at positive and negative offsets from the zero crossing point, with the samples processed to identify a direction of the rotor flux axis. Further samples of at least one motor current signal are taken with respect to a certain phase reference, and the samples compared to resolve a polarity of the rotor flux axis which is indicative of the angular position of the rotor.

In one or more example embodiments, an apparatus to control an elevator may include a motor having a rotor configured to rotate with a magnetic axis to drive the elevator at a speed based on a current applied thereto; and a processor configured to regulate the speed of the elevator without information on a speed or an angle of the rotor from an encoder or motion sensor.