A low cost and efficient method and apparatus for calibrating high performance internal permanent magnet motors that involves starting from an initial estimation of the rotor position and improving the estimation incrementally by successively commanding various current vectors and making adjustments to the estimated initial position according to the rotor's physical reaction to such current vectors.

In an electrified vehicle having a synchronous traction motor, an inverter is connected to stator windings by three power cables. If these cables are accidentally connected to the wrong windings, the resulting torque will not match the desired torque, and may even be in the wrong direction. To avoid this problem, a test is performed any time that the cables may have been unplugged and re-connected. The inverter is commanded to generate a rotating magnetic field while the rotor is held stationary, resulting in a positive and a negative response current. A relationship between a phase angle of the negative response current and the rotor position indicates which cables are connected to which windings. If the cables are incorrectly connected, the controller disables the motor and informs an operator which cables to swap to achieve correct connection.

In an electrified vehicle having a synchronous traction motor, an inverter is connected to stator windings by three power cables. If these cables are accidentally connected to the wrong windings, the resulting torque will not match the desired torque, and may even be in the wrong direction. To avoid this problem, a test is performed any time that the cables may have been unplugged and re-connected. The inverter is commanded to generate a rotating magnetic field while the rotor is held stationary, resulting in a positive and a negative response current. A relationship between a phase angle of the negative response current and the rotor position indicates which cables are connected to which windings. If the cables are incorrectly connected, the controller disables the motor and informs an operator which cables to swap to achieve correct connection.

A motor drive device can include: a control circuit configured to adjust each phase current of a three-phase inverter of a motor; where the phase current of the three-phase inverter rises from zero to a first threshold during a first time interval; and where the phase current is controlled to drop gradually from the first threshold to zero during a second time interval in order to increase the second time interval.

A motor drive device can include: a control circuit configured to adjust each phase current of a three-phase inverter of a motor; where the phase current of the three-phase inverter rises from zero to a first threshold during a first time interval; and where the phase current is controlled to drop gradually from the first threshold to zero during a second time interval in order to increase the second time interval.

In one aspect, a system for determining an initial angular position of a rotor of a synchronous machine includes a motor driver module configured to provide a motor driver voltage signal to the synchronous machine, the motor driver voltage signal being sufficient to induce an electrical current in the synchronous machine; and a rotor position determination module configured to receive an indication of the current generated in the machine and to determine the initial position of the rotor based on the indication of the current generated in the machine. The motor driver voltage signal includes at least a first portion, a second portion, and a third portion, the first portion has a first non-zero voltage during a first temporal duration, the second portion has a second non-zero voltage during a second temporal duration, and the third portion has a substantially zero voltage during a third temporal duration, the first portion has a first polarity and the second portion has a second polarity that is opposite to the first polarity, and the first temporal duration and the second temporal duration are different.

In one aspect, a system for determining an initial angular position of a rotor of a synchronous machine includes a motor driver module configured to provide a motor driver voltage signal to the synchronous machine, the motor driver voltage signal being sufficient to induce an electrical current in the synchronous machine; and a rotor position determination module configured to receive an indication of the current generated in the machine and to determine the initial position of the rotor based on the indication of the current generated in the machine. The motor driver voltage signal includes at least a first portion, a second portion, and a third portion, the first portion has a first non-zero voltage during a first temporal duration, the second portion has a second non-zero voltage during a second temporal duration, and the third portion has a substantially zero voltage during a third temporal duration, the first portion has a first polarity and the second portion has a second polarity that is opposite to the first polarity, and the first temporal duration and the second temporal duration are different.

A control device of a permanent magnet synchronous motor that is a control device of a sensorless-type permanent magnet synchronous motor in which a rotor using a permanent magnet rotates by a rotating magnetic field caused by a current flowing in an armature includes: a driver that applies a voltage to the armature and drives the rotor; an initial position estimator that estimates an initial position which is a magnetic pole position of the rotor that is stopped; and a controller that controls the driver so as to apply a pulse train including a voltage pulse for searching the initial position for each of n angle positions dividing a search range of an electrical angle of 360 degrees to the armature, wherein the pulse train includes a first pulse and a second pulse.

In a motor control device, when estimating an initial position of a magnetic pole of a rotor of a motor, a drive circuit continuously or intermittently applies a voltage to a stator winding at each of a plurality of energization angles while sequentially changing the energization angles, and at a voltage value and for an energization time period, the voltage value and the energization time period being set such that the rotor does not rotate. An initial position estimation unit calculates an estimated initial position of the magnetic pole of the rotor based on a phase angle of a trigonometric function curve that approximates a change of a -axis current I with respect to each of the energization angles. The trigonometric function curve has a cycle equal to one electrical cycle of the motor.

A method is described for estimating a position of a rotor in a synchronous electric machine having a rotor. The method has the steps of: inputting the initial rotor angle into a power converter, injecting a first voltage waveform with a first fundamental frequency into the power converter,injecting a second voltage waveform with a second fundamental frequency into the power converter, the second voltage waveform being offset with an offset angle , determining a resulting second axis current in the power converter at the second fundamental frequency, adjusting, for each torque value, the offset angle so that the resulting second axis current at the second fundamental frequency becomes zero, and estimating the position of the rotor based on the plurality of offset angle values.