Optimal stator current design has been widely investigated for torque ripple minimization of permanent magnet synchronous machines (PMSMs). The optimal current design requires accurate machine ...parameters including the permanent magnet flux and dq-axis inductances, which are varying during machine operation due to machine uncertainty. Therefore, this paper investigates how these machine parameter variations influence the optimal stator current design, and hence the torque ripple minimization performance. At first, torque ripple model-based analytical solution for optimal current design is introduced in this paper, which can theoretically reduce the torque ripple to zero. Then, machine parameter variations of a laboratory interior PMSM are tested and analyzed. It is found that the magnet flux under no load can be reduced by more than 10% from room temperature to the maximal operation temperature, and the inductance term (L d -L q ) can be reduced by more than 50% from no load to full load. Afterwards, analytical equations are derived to quantify the resultant torque ripples due to the variations of magnet flux, dq-axis inductances, and the cogging torque. Finally, the numerical and experimental studies are conducted to investigate the resultant torque ripples under different percentages of parameter variations.
Vector control plays a critical role in a permanent magnet synchronous motor (PMSM) drive to deliver the desired torque in electrified vehicle applications. Motor speed and stator current control ...depend on various nonlinear motor parameters that influence the performance of PMSM. Moreover, tuning of speed and current controller parameters using conventional control techniques also depends on these PMSM parameters. To enhance the robustness of vector control and tracking methodology against PMSM parameter uncertainties and load disturbances, a novel deep reinforcement learning (DRL) based advanced speed and current control technique is proposed in this article. The proposed method mitigates the effects of disturbance due to parameter variations as well as the load torque. The novel architecture delivers closed-loop reinforcement learning agents trained with the deep deterministic policy gradient learning algorithm in the plant environment where the cost of exploration is expensive. First, an overview and need for the proposed DRL vector control architecture are provided. Subsequently, the design and training methods for the proposed DRL controller are elicited. Thereafter, the proposed control scheme is validated with real-time software-in-the-loop testing under various conditions and compared against adaptive proportional-integral control of the same PMSM in OPAL-RT simulator.
In the field of heat transfer in permanent magnet synchronous motors (PMSM) for electric vehicles, the boundary element method (BEM) has been applied for the first time to calculate the steady-state ...temperature of the PMSM with a spiral water-cooled system. In this investigation, the boundary-integration equation for the steady-state heat transfer problem of a water-cooled PMSM is first derived on the basis of thermodynamic theory, and the system of constant coefficient differential equations is obtained by discretizing its boundaries, while the temperature results obtained from the BEM are compared with the finite element method (FEM) results. Furthermore, the temperature distribution and heat transfer characteristics obtained from the FEM and BEM were verified twice using the PMSM prototype and test platform. The results show that the maximum relative error between the temperature calculation results of FEM and BEM is 1.97%, and the maximum relative error between the results of BEM and the test does not exceed 3%, which finally verifies the validity and accuracy of BEM in solving the heat transfer problems of water-cooled PMSM.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The control of (PMSM) is the subject of this study and the torque ripple reduction in (PMSM) is the main goal of this work. Torque and flux are controlled using a predictive model and Vector Control. ...Because it is commonly employed in regulating electric motors. Space vector control and predictive control are two (PMSM) control approaches used in this study. Predictive control was determined to be more effective in terms of response and action after a Matlab simulation of the two approaches. MPC covers all potential switching states that decrease actual torque and flux ripples as well as Total Harmonic Distortion. The benefits of MPC include simple principles, an easy-to-use console, and the ability to implement limits quickly. However, there are some drawbacks to this technique, including the requirement for bigger accounts and faster machines. The fundamental principles of the control techniques discussed are provided A (PMSM) powered by a two-level power converter is then used to simulate the control approaches. Their performance in comparison is based on the obtained results.
This paper presents a detailed analysis of short-circuit current behavior during interturn short-circuit faults in permanent magnet synchronous machines (PMSMs) by considering the short-circuit ...contact resistance. For this purpose, an finite element analysis (FEA)-based equivalent circuit model is developed to understand the circulating current behavior in the shorted turns. Various fault resistance and number of shorted turn combinations are examined at different torque and speed levels. To include saturation due to high fault currents, the inductance matrix of faulty machine is created in FEA environment and incorporated into the equivalent circuit model as four-dimensional lookup tables. In order to take loop responses into account, the model is controlled through field oriented control (FOC) with closed speed and current loops. An experimental setup is built to verify the simulation results using a PMSM with several winding taps. It is shown that the experimental results and the simulations are quite consistent with each other. The findings from this study are essential to predict fault severity, develop mitigation techniques and determine the safe operating area for faulty machines.
Synchronous-frame proportional-integral (PI) current control is the most popular solution in industrial permanent-magnet synchronous motor (PMSM) drive systems. However, due to the nonlinearities ...from large parameter uncertainties and complex operating conditions, it is challenging to select the parameters of the PI controller with satisfactory performance by trial-and-error. To this end, this paper presents an uncertainty-and-disturbance-estimator-based current control scheme for PMSM drives, which has a simple structure and is robust to machine parameter perturbations. Meanwhile, it is interesting that the controller parameters (proportional and integral gains) are simply expressed in the desired closed-loop bandwidth and the approximate lumped disturbance bandwidth. A simple dual-loop tuning algorithm is also proposed to select the appropriate controller parameters, and trial-and-error can be largely avoided. Finally, the efficacy of the proposed control method is fully supported by comparative experimental validation with the synchronous-frame PI control on a dSPACE DS1103-based PMSM drive prototype.
This article introduces an injectionless approach for acoustic-noise-based sensorless control of the permanent magnet synchronous machine. Replacing the high-frequency injection, the pulsewidth ...modulation (PWM) voltages are used as the basis for the method implementation. The mathematical model of PWM with considering the deadtime effect is first presented. Then, its impact upon the harmonics of current, magnetic fields, and generated radial forces is detailed. It is experimentally verified that in the presence of deadtime, unlike the contaminated current profile, there are merely specific-order speed-dependent components appeared in the acoustic noise spectrum, which is a clear bonus for signal processing precision and estimation performance. Moreover, a novel phase-locked loop (PLL) topology comprising a resonant-controller-based feedforward compensation block (RCPLL) is proposed. This compensation block is integrated within the PLL, by which the extra harmonics in the PLL error are directly suppressed, and therefore, the estimation performance is noticeably enhanced. The robustness of the proposed sensorless algorithm, alone, is verified experimentally under different conditions, and then, the estimation performances with and without the proposed RCPLL are compared.
In this article, a multigain online autotuning technique-based discrete-time current regulator for permanent magnet synchronous motors is proposed. With the nominal current regulator in the proposed ...control scheme, the performance and robustness of the current control system are improved. Then, a multigain online autotuning method is proposed to further suppress the adverse effects of parametric uncertainties. In the proposed approach, the voltage vectors of the current regulator are mapped to an extended synchronous reference frame, based on which an adaptive observer is constructed without approximation to autotune the gains of the current regulator online. Compared with traditional recursive least-squares methods, the proposed autotuning method can be implemented with greatly reduced computational burden. The proposed current control method is designed directly in the discrete-time domain, which guarantees the control performance in digital implementations. In addition, the proposed current control method can be applied to both the interior and surface-mounted permanent magnet synchronous motors. Finally, theoretical analysis and comparative experiments verify the effectiveness of the proposed method.
