Mathematical Analysis of Current on DC-Link Capacitor in Dual Three-Phase PMSM Drive System

For a motor drive system, the capacitor at the bus end is one of the main components. The DC bus capacitor is often used as an energy storage device to maintain the power balance between the AC side output power and the DC side input power of the driver system, and reduce the impact of the current ripple. Therefore, the reliability of the DC bus capacitor is one of the main factors affecting the drive system. The current ripple is high-order harmonics, which distorts the current, resulting in faster heating of the capacitor and damage to internal components. Therefore, the complete mathematical model of the DC-link capacitor current is critical for suppressing the capacitor current ripple and provides the necessary theoretical basis. Dual three-phase permanent magnet synchronous motors are widely used due to high fault tolerance and low voltage characteristics. In this paper, a novel mathematical model of current ripple on DC-link capacitor is proposed for dual three-phase PMSM drive system, and the accuracy of the mathematical model is verified by simulation results.