Torque and flux control of induction motors fed by synchronized and symmetrical voltage pulses

The low switching frequency in high-power motor drives is mandatory for reducing thermal stress on power devices but often results in significant current harmonics. Synchronized space vector modulation (SynSVM), a widely used low-carrier-ratio PWM strategy, offers a simple implementation and reduced harmonics. However, implementing SynSVM in traditional AC motor current regulation poses challenges due to fixed voltage samples. To address this, a high-performance control scheme based on SynSVM is proposed in this manuscript. It ensures the stator flux vector follows a predefined trajectory by integrating voltage pulses from the original SynSVM. The basic voltage vector switching is facilitated through high-frequency monitoring and compensation of torque and flux errors, resulting in a fast torque response. Furthermore, synchronized and symmetrical voltage pulses, inherent in the original SynSVM, are equivalently generated, to effectively mitigate current harmonics. This proposed method liberates designers from the complexities of current regulation based on SynSVM. Both simulations and experiments validate the efficacy of the proposed method. An equivalent realization of synchronized space vector modulation (SynSVM) based on the stator flux trajectory tracking is proposed, providing both low current harmonics and fast torque response for the low-switching-frequency induction motor drive. image