Dual Cost Function Model Predictive Direct Speed Control With Duty Ratio Optimization for PMSM Drives

Abstract

Traditional speed control of permanent magnet synchronous motors (PMSMs) includes a cascaded speed loop with proportional-integral (PI) regulators. The output of this outer speed loop, i.e. electromagnetic torque reference, is in turn fed to either the inner current controller or the direct torque controller. This cascaded control structure leads to relatively slow dynamic response, and more importantly, larger speed ripples. This paper presents a new dual cost function model predictive direct speed control (DCF-MPDSC) with duty ratio optimization for PMSM drives. By employing accurate system status prediction, optimized duty ratios between one zero voltage vector and one active voltage vector are firstly deduced based on the deadbeat criterion. Then, two separate cost functions are formulated sequentially to refine the combinations of voltage vectors, which provide two-degree-of-freedom control capability. Specifically, the first cost function results in better dynamic response, while the second one contributes to speed ripple reduction and steady-state offset elimination. The proposed control strategy has been validated by both Simulink simulation and hardware-in-the-loop (HIL) experiment. Compared to existing control methods, the proposed DCF-MPDSC can reach the speed reference rapidly with very small speed ripple and offset.INDEX TERMS Model predictive control, direct speed control, hardware-in-the-loop, permanent magnet synchronous machine.

Direct Torque Control for Permanent Magnet Synchronous Motor Using Golden Eagle Optimized ANFIS

“…Where Table 6 shows the comparative analysis of Total Harmonic Distortion. The control approach with the suggested GEO-ANFIS controller outperforms the existing DCF-MPDSC [22] and ANFIS controller.…”

“…The Space Vector Pulse Width Modulation based DTC (SVPWM-DTC) [21] was suggested for PMSM; due to the bandwidth constraint, it causes a huge torque ripple in the motor. A novel Dual Cost Function Model Predictive Direct Speed Control (DCF-MPDSC) [22] was presented with duty ratio optimization for PMSM drives. Even though several equations are involved, only one voltage vector is applied throughout the control period which resulting in a huge torque ripple.…”

Model-Free Predictive Current Control for SynRM Drives Based on Optimized Modulation of Triple-Voltage-Vector

“…This may result in unacceptable current ripples and unsatisfactory steady-state performance [20]. Some solutions have been proposed to cope with the problem, such as duty ratio optimizations [21][22][23][24] and modulation-based MPCCs [25][26]. Zhang et al [21] proposed a non-zero voltage vector paired with a zero voltage vector to achieve ripple reduction.…”

“…However, variations in the amplitudes of the virtual and primary voltage vectors can result in unbalanced and reduced dc-link voltage utilization. Deadbeat control is also proposed in [23] to optimize the control of duty ratio. Two optimizations in terms of minimum cost are performed therein in selecting the best combination of voltage vectors in sequence.…”

“…The conduction duration herein is designed to perform at an adaptive duty ratio. However, heavy power ripples and harmonics in [21][22][23][24][25][26][27] are not effectively suppressed because of less applied vectors [28]. As a solution, [29][30] and [32] proposed an MPCC using three vectors.…”