image: The developed DTP-OW-PMSM drive has two sets of three-phase windings with a spatial phase shift of 30 electric degrees. Four inverters are powered by three DC sources with a voltage ratio of 2:1:1 to achieve a four-level effect
Credit: Haowen Jiang
Research content
To achieve high power rating and low current harmonics of motor drive, this paper developed a DTP-OW-PMSM drive with the DC-link voltage ratio of 2:1:1. Based on this topology, this paper proposed a DTP-FL SVPWM strategy. First, two identical three-phase four-level space vector diagrams are constructed and divided. Then, three adjacent vectors nearest to the reference vector in each diagram are selected for the vector synthesis to guarantee high modulation precision and low switching frequency. Furthermore, to avoid the modulation error caused by the voltage deviation, the proposed DTP-FL SVPWM strategy is further optimized through unified duty ratio compensation (UDRC). The effectiveness of the proposed strategy is verified through experiments.
The research results and their significance
Simulation and experimental results confirmed that the proposed DTP-FL SVPWM strategy effectively enhances the performance of the motor drive in multiple aspects. Compared to traditional modulation strategies, in the entire modulation range, average current THD are reduced by more than 29%. The average switching frequencies of the high-voltage side and low-voltage side inverters are reduced by 90% and 32%, respectively. Furthermore, when the UDRC method is applied during voltage deviations, average current THD are reduced by 50%.
These advancements are particularly valuable for electric vehicle propulsion systems, aerospace actuators, and industrial automation, where precise and efficient motor control directly affects performance, safety, and system lifespan.
Future outlook
In the future, researchers plan to focus on fault diagnosis and fault-tolerant control based on developed topology and proposed strategies, enabling the motor drive to maintain stable operation even in the event of inverter failures or DC-link disturbances.
With the rapid development of the electric vehicle and renewable energy systems, this high-precision modulation technology is expected to play a key role in enhancing the efficiency, reliability, and energy utilization of next-generation motor drive.
The complete study is accessible by DOI:10.30941/CESTEMS.2025.00023
Journal
CES Transactions on Electrical Machines and Systems
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Four-Level SVPWM Strategy of Dual Three-Phase Open-Winding PMSM Drive
Article Publication Date
15-Sep-2025