Method and apparatus for controlling an electrical machine

摘要

An observer (404), operating during a time when open loop control (402) is being used to drive a synchronous motor (401), the output of the observer (404) being a signal, E_I_angle, related to the angle between a rotational EMF vector and the current excitation vector, the observer (404) determining the angle by an iterative calculation incorporating a summation term, the summation term summing the variation of the quadrature component of a rotational EMF vector relative to an estimated EMF position vector, and using the angle output of the observer to update the estimate of the rotational EMF position vector. In a further aspect of the invention the observer output signal, E_I_angle, can be used to determine the transition to closed loop control (405), when the observer output signal reaches a value indicating conditions close to pull out conditions.

主权项

1. A control system for an electrical machine, and comprising:
an observer configured to operate during a time when open loop control is being used to drive an electrical machine, and further configured to output a signal, E_I_angle, related to the angle between a rotational EMF vector and a current excitation vector provided by an inverter configured to control an electrical machine, wherein the observer is configured to determine the angle by an iterative calculation comprising a summation term, the summation term summing the variation of a quadrature component of the rotational EMF vector relative to an estimated EMF position vector, and wherein the controller system is configured to use the angle output by the observer to update the estimated angular position of the rotational EMF position vector.