This study aims to enhance the performance of sensorless vector control for permanent magnet synchronous motor (PMSM) drives by developing an improved sliding-mode observer (SMO) with current disturbance compensation (CDC). This observer is designed to achieve chattering attenuation induced by sliding-mode dynamics while improving the estimation accuracy of both current and rotor position parameters.
To address the chattering and disturbance rejection shortcomings of conventional first-order SMOs, this paper proposes a higher-order SMO based on a hyperbolic tangent sliding surface (HTSMO) and then deeply integrates it with CDC, forming the CDC-HTSMO. First, a hyperbolic tangent sliding-mode surface is designed to achieve chattering suppression. Then, considering external current disturbances, CDC is added to the observed current to reduce current errors.
Comparative experiments are conducted to verify the effectiveness of CDC-HTSMO in current disturbance and rotor position compensation. The final results demonstrate that the proposed method exhibits excellent performance in reducing chattering, suppressing current ripple and improving rotor position estimation accuracy.
The improved observer proposed in this study is co-developed and experimentally validated with SMO based on a first-order sliding-mode framework and an extended-model-based full-order sliding-mode observer. Systematic comparative analyses are conducted under diverse operating conditions, including speed variations, no-load/load disturbances and parameter variations.
