Instantaneous DC-Link Voltage Control for Electrolytic Capacitors-less PMSM Drives

In this paper, a novel instantaneous voltage control strategy for electrolytic capacitor-less (ECL) PMSM drives is proposed to improve the motor dynamic performance. The principle of dc-link voltage ripple in ECL drives is analyzed and the mathematical model of the dc-link instantaneous voltage is established according to the power characteristics of the ECL PMSM drives. Then, the instantaneous voltage instead of constant voltage is utilized as the voltage reference, which can quickly respond to the load variation. Furtherly, in order to accurately track the command voltage, a proportional resonance (PR) controller is adopted. Simulation results verify the effectiveness of the control strategy. The comparison of the motor dynamic performance shows that the instantaneous voltage control strategy is superior to the conventional control strategy of ECL PMSM drives.