The invention discloses a method for determining a q-axis
current compensation value of a
permanent magnet synchronous motor and a pulsation suppression method. The method comprises the following steps: synchronously acquiring a q-axis current feedback
signal iq and a rotor position
signal theta m, determining a position interval of a rotor based on the theta m, accumulating the interval times by1 and performing synchronous averaging on the iq, and repeatedly acquiring until the accumulated value of the interval times is greater than a threshold value and all the intervals are not overlappedto form a circle of the rotor; performing
fast Fourier transform on the synchronous average value corresponding to each interval arranged in sequence to obtain
frequency domain characteristic information, determining the amplitude and the
phase angle of a to-be-compensated
spatial frequency component from the
frequency characteristic information, and constructing a q-axis
current compensation function; and obtaining a q-axis
current compensation value based on the position of the actual compensation moment of the motor rotor and the current compensation function.
Time domain information is converted into a space domain,
time lag is avoided, the whole process does not affect the dynamic performance of the
system, extra devices are not needed, structures and parameters of all control links do not need to be adjusted, and operation is easy.