Abstract
In this paper, a new modulated finite control set-model predictive control (FCS-MPC) methodology is proposed for a quasi-Z-source inverter (qZSI). The application of the qZSI in this paper is to drive the permanent magnet synchronous machine (PMSM). The proposed methodology calculates the optimal duration time (ODT) for the candidate vector from the switching patterns of the inverter after it is selected from the FCS-MPC algorithm. The control objective of the FCS-MPC are the three-phase currents of PMSM, when the motor speed is below or equal to the base speed. While at a speed beyond the based speed, the inductor current and capacitor voltage of the qZS network are added as control objectives. For each candidate optimal vector, the optimal time, which is a part of the sampling interval, is determined based on minimizing the ripples of the control objectives using a quadratic cost function. Then, the optimal vector is applied only to the inverter switches during the calculated ODT at the start of the sampling interval, while the zero vector is applied during the remaining part of the sampling interval. To reduce the calculation burden, the zero-state is excluded from the possible states of the inverter, and the sub-cost function definition is used for the inductor current regulation. The proposed modulated FCS-MPC is compared with the unmodulated FCS-MPC at the same parameters to handle a fair comparison. The simulation results based on the MATLAB/Simulink© software shows the superiority of the proposed algorithm compared to the unmodulated FCS-MPC in terms of a lower ripple in the inductor current and capacitor voltage, and a lower THD for the PMSM currents.
Highlights
The quasi-Z-source inverter has been introduced in research as an advanced topology from the primary one, ZSI, by reserving the same number of components [1,2]
This paper proposes a methodology for calculating the optimal duration time (ODT) to reduce the ripples in the quasi-Z-source inverter (qZSI) inductor current and capacitor voltage and the permanent magnet synchronous machine (PMSM) currents
Simulation results are presented in this arrangement to verify the effect of the proposed modulated finite control set-model predictive control (FCS-model predictive control (MPC)) over the conventional MPC on the performance of PMSM driven by qZSI as follows: (1) the dynamic performance of the PMSM and Qzsi sides has been simulated and analyzed for both modulated and unmodulated FCS-MPCs, (2) control variables
Summary
The quasi-Z-source inverter (qZSI) has been introduced in research as an advanced topology from the primary one, ZSI, by reserving the same number of components [1,2]. In [24], an improved finite-time tracking control command filter was designed to ensure that the output of the filter can approximate the derivatives of virtual signals more quickly, suppress chattering, and relax the input signal limit of the Levant differentiator These references have presented promising control methodologies with some stability analysis, their validity can be reliable when applied to electrical drive and motor control systems. This paper proposes a methodology for calculating the optimal duration time (ODT) to reduce the ripples in the qZSI inductor current and capacitor voltage and the PMSM currents. Using the zero vector after the shoot-through vector prevents the inductor current to continue charging until the sampling interval ends, while for the PMSM currents, optimizing the time to apply the active vector minimizes the total harmonics distortion (THD) This is beneficial to the high sampling rate in case of using the low-cost digital platform in the implementation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.