The drive inverters for high-power motors often need to reduce the carrier ratio (usually by reducing the lower switching frequency) to increase its capacity. However, the low carrier ratio results in motor control performance degradation. In this paper, an inverter and a permanent magnet synchronous motor (PMSM) are integrated to establish a unified prediction model with the delay caused by sampling and modulation that cannot be ignored under a low carrier ratio. Based on this model, a new PWM predictive control suitable for low carrier ratio (PPC-LCR) is proposed, which has better stability, dynamic performance, model accuracy and robustness under a low carrier ratio. To further enhance the control accuracy of the proposed strategy, prediction errors by parameter mismatch are analyzed, and a correction method of feedbacking the last beat prediction error is proposed to compensate for model error and parameter mismatch. Finally, experimental results are presented to support theoretical analysis and the proposed strategy.

大功率电动机的驱动逆变器通常需要降低载频比（通常通过降低较低的开关频率）来增加其容量。但是，低的载流子比导致电动机控制性能下降。本文将逆变器和永磁同步电动机（PMSM）集成在一起，以建立一个统一的预测模型，该模型具有在低载频比下无法忽略的采样和调制引起的延迟。在此模型的基础上，提出了一种适用于低载频比的新型PWM预测控制（PPC-LCR），其在低载频比下具有较好的稳定性，动态性能，模型精度和鲁棒性。为了进一步提高所提出策略的控制精度，分析了参数不匹配带来的预测误差，提出了一种反馈最后一次心跳预测误差的校正方法，以补偿模型误差和参数失配。最后，给出实验结果以支持理论分析和提出的策略。