Abb Oy

Abb Schweiz Ag

Antti Piippo

Janne Salomäki

Jani Kangas

Jussi Rantanen

Samuli Kallio

Matti Eskola

Joni Heikkilä

The present disclosure describes a two-stage method for estimating an angle offset of an angle sensor in a system comprising a permanent-magnet synchronous motor. An initial value for the estimated angle offset is first determined with a short circuit test. Next, a torque of the motor may be controlled so that the motor is maintained at a zero speed. Minor adjustments are made to the value of the angle offset to find a minimum magnitude of stator current. A value at which the stator current is at its minimum is used as a final angle offset.

Method and apparatus for estimating an angle offset of an angle sensor

A method and an arrangement are provided for controlling a sensorless permanent magnet synchronous machine using a frequency converter connected to feed the machine with electrical power. A current vector having a magnitude is produced to the stator of the machine with the frequency converter, and the current vector is rotated for rotating the rotor of the machine. Prior to starting the drive, a value is defined for the magnitude of the current vector and a frequency limit. The defined value is used as the magnitude of the current vector when the rotor of the machine is rotated with a frequency that is lower than the defined frequency limit. A vector control method is used for controlling the machine when the frequency of the machine is higher than or equal to the defined frequency limit.

Method and arrangement for controlling permanent magnet synchronous machines

A method of estimating stator resistance of a permanent magnet synchronous machine, when the permanent magnet synchronous machine is controlled with an inverter using a control system having an adaptive observer which is augmented with a signal injection, the adaptive observer having a stator resistance estimate ({circumflex over (R)}) as a parameter, in which method an error signal (&#x3b5;) is obtained from the signal injection, a speed correction term (&#x3c9;) is calculated from the error signal (&#x3b5;), the rotor position estimate is corrected using the speed correction term (&#x3c9;) in the adaptive observer, whereby the error signal (&#x3b5;) is driven to zero. The method comprises the step of correcting the value of the stator resistance estimate ({circumflex over (R)}) in the adaptive observer when the speed correction term (&#x3c9;) differs from zero.

Stator resistance adaptation in sensorless PMSM drives

A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine, when the permanent magnet synchronous machine is fed with a frequency converter, the method comprising the steps of forming a stator voltage reference for the permanent magnet synchronous machine, injecting a high frequency signal (u) into the stator voltage reference, measuring a DC-link current (i) of the frequency converter when the permanent magnet synchronous machine () is fed with a voltage (u) corresponding to a sum of the stator voltage reference and the injected signal, calculating a stator current estimate (&#xee;), calculating a current error (&#x129;) as a difference between the stator current estimate and the measured DC-link current, and estimating a rotor speed ({circumflex over (&#x3c9;)}) and position ({circumflex over (&#x3b8;)}) of the permanent synchronous machine based on the current error. The injected high frequency signal (u) comprises a direct axis component and a quadrature axis component, the direct axis component having a first frequency and the quadrature axis component having a second frequency, the first and second frequencies being different.

Method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine

A method and a system in connection with a speed and position sensorless permanent magnet synchronous machine equipped with an output filter and driven by an inverter, which method comprises the steps of forming a speed-adaptive full-order observer based on the dynamic model of the combination of the permanent magnet synchronous machine (PMSM) and the output filter, measuring the inverter output current (i), estimating inverter output current (&#xee;), determining the estimate for the electrical angular speed ({circumflex over (&#x3c9;)}) using the estimated and measured inverter output currents (&#xee;, i) in an adaptation law, injecting a voltage signal (u) into the inverter voltage reference (u) to obtain a modified voltage reference (u), detecting an error signal (&#x3b5;) from the measured inverter output current (i), and calculating the speed correction term (&#x3c9;) used in the adaptation of the observer from the error signal (&#x3b5;).

Method and system in connection with permanent magnet synchronous machines

A method for determining the speed and position of a rotor of a salient-pole permanent magnet synchronous machine, the method comprising the steps of creating a voltage model () on a permanent magnet synchronous machine, forming a voltage reference (u) for a stator of the permanent magnet synchronous machine, determining stator currents (is) of the permanent magnet synchronous machine, calculating a rotor angular speed () from the voltage reference (u) and the stator currents (i) using the voltage model (). The method further comprises the steps of forming with signal injection a position tracking signal (&#x3b5;) of the rotor of the permanent magnet synchronous machine, forming a rotor angular speed estimate ({circumflex over (&#x3c9;)}) from the calculated rotor angular speed () and the rotor position tracking signal (&#x3b5;), forming a rotor position angle estimate ({circumflex over (&#x3b8;)}) from the formed rotor angular speed estimate ({circumflex over (&#x3c9;)}) and the rotor position tracking signal (&#x3b5;).

Method in salient-pole permanent magnet synchronous machine

A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine the method comprising the steps of calculating first stator flux vector estimate ({circumflex over (&#x3c8;)}+j{circumflex over (&#x3c8;)}) using the flux model and measured stator currents, calculating second stator flux vector estimate ({circumflex over (&#x3c8;)}+j{circumflex over (&#x3c8;)}) using the voltage model and measured stator voltages, comparing the directions of the first and second flux vectors to achieve a first error signal (F), using speed adaptation to achieve estimates for the rotor angular speed ({circumflex over (&#x3c9;)}) and angular position ({circumflex over (&#x3b8;)}) from the first error signal (F), injecting a known voltage signal (u) to the stator voltage, detecting a current signal (i) from the stator current to form a second error (&#x3b5;) signal, which is dependent on the estimation error of the rotor position, augmenting the voltage model by the second error signal (&#x3b5;) to keep the first and second flux vector estimates aligned and so to correct the rotor angular speed ({circumflex over (&#x3c9;)}) and angular position ({circumflex over (&#x3b8;)}) estimates.

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Espoo, Finland

Antti Piippo