基于多调制模式的五相串绕组逆变器电路电流谐波抑制控制

Compared with conventional three-phase permanent magnet synchronous motors (PMSMs), multi-phase PMSMs have a lower voltage level and stronger fault-tolerant capability on the same operation condition. This paper replaces the star-connected winding inverter with the series-end winding (SW) inverter to reduce the requirements for DC-link voltage further and improve DC-link voltage utilization. However, phase windings are connected end to end in the SW inverter, which leads to a zero-sequence loop and results in the zero-sequence current (ZSC) in the phase current. Thus, a harmonic current suppression method based on multi modulation patterns for a five-phase PMSM SW inverter is proposed. Based on the model predictive control, the method considers all the voltage vectors in the SW inverter and chooses the optimal modulation pattern for the harmonic current suppression. A time delay compensation is needed during the calculation of reference voltages according to the machine model. Due to the large number of voltage vectors in the five-phase SW inverter, they can be divided into 12 sectors according to the outermost vectors. There are 7 voltage vectors in each sector. Then, the predictive currents under different modulation patterns are obtained after determining the sector of the reference voltages. The modulation pattern with the minimum harmonic currents is acquired based on the cost function. This control strategy not only suppresses harmonic currents but also reduces the number of calculations for predictive currents.