Abstract:
To solve the problems of unfixed switching frequency and high computational complexity of the traditional three-vector model predictive current control (TV-MPCC) strategy for permanent magnet synchronous motor (PMSM), a fixed switching frequency three-vector model predictive current control (FSF-TV-MPCC) strategy is proposed, which avoids the invalid enumeration calculation and reduces the switching frequency and computational complexity by selecting the optimal voltage vector and the sub-optimal voltage vector based on the zero voltage vector of previous cycle and the sector where the reference voltage vector of the current cycle is located. The current difference parameters of
d-axis and
q-axis are introduced to calculate the action time of the voltage vector, which ensures that the action time of the voltage vector is always greater than zero and the switching frequency is fixed. Taking the surface permanent magnet synchronous motor driven by three-phase two-level voltage source inverter (VSI) as the controlled object, the traditional TV-MPCC and FSF-TV-MPCC are compared through simulation and experiment. The simulation and experiment results show that the FSF-TV-MPCC can reduce the computational complexity and switching frequency, and can fix the switching frequency on the basis of ensuring the steady-state and dynamic performance of the system.