| 摘要 |
The present invention relates to control of electrical machines and in particular, though not exclusively, to control of synchronous machines such as hybrid stepping motors, flux switching machines and brushless permanent magnet motors and generators. A sensorless control system for an electrical machine is provided comprising a rotor, a stator having one or more phase windings for generating a rotating stator magnetic field, the system comprising detection means for monitoring the currents in the phase windings providing a real component Is—real along a real axis at a known angle in line with a rotating reference frame and an imaginary component Is—imag orthogonal to the real component Is—real, calculating means for determining a value of the real component Es—real of the rotational emf along an axis at a known angle in line with a rotating reference frame and an imaginary component (Es—imag) orthogonal to the real component (Es—real), estimating means for estimating an angular position of the rotational emf vector using at least one of the estimated orthogonal components of the emf, error means for determining an angular error signal indicative of the deviation of the estimated angular position from a desired position, and synchronising means for controlling the machine such that the error signal tends towards zero. |
