Evaluation of several modulation-based field-oriented control algorithms for PMSM drive systems

This study compares Field-Oriented Control (FOC) and trapezoidal control techniques for Permanent Magnet Synchronous Motors (PMSMs) in modern industrial variable-speed applications. Traditionally, variable-speed applications have relied on DC machines, which have inherent drawbacks such as increased maintenance, spark losses, higher inertia, and overall higher costs. This FOC has emerged as a sophisticated method that enables independent control of torque and magnetization flux in AC motors, allowing for precise regulation of torque and speed tailored to the motor's electromagnetic state. FOC leverages Sinusoidal Pulse-Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM) techniques to enhance DC voltage utilization and minimize switching and harmonic losses. In contrast, the paper presents a detailed model of a PMSM drive system based on electronic components rather than standard mathematical blocks, leading to more realistic simulation results. All simulation modules, including the inverter and PWM generator, were custom-built, allowing for performance comparison under varying speed and torque conditions. Brushless DC (BLDC) motors, which are typically categorized as PMSMs with trapezoidal back-EMF waveforms, have gained traction due to their simplicity and cost-effectiveness. The trapezoidal control technique, also known as six-step commutation, simplifies the control process by aligning motor phase switching with the rotor position, resulting in a quasi-square-wave current. However, this method introduces torque ripple and presents control challenges, particularly in low-speed applications. Given the rising economic constraints and stringent governmental standards, there is an increasing demand for efficient, low-interference, and adaptable electrical systems. This study demonstrates that FOC provides a more robust and efficient solution for high-performance applications than the trapezoidal control technique in PMSMs.

Permanent Magnet Synchronous Motors (PMSM) are considered as energy efficient motors suitable for modern applications like electric vehicles. Field oriented control or vector control is a superior control strategy for PMSM drives. It is known that in vector control, decoupled control of torque and flux is obtained as in the case of a DC motor. The objective of this paper is to compare and analyze the performance of a vector controlled Permanent Magnet Synchronous Motor which uses Sinusoidal PWM and space vector PWM techniques. Sinusoidal PWM and Space vector PWM are pulse width modulation techniques used for controlling the three phase inverter which drives the motor. They have the advantage of decreased harmonic content in the generated output voltage. Space vector modulation has the added advantage of increased DC bus utilization. Here both the methods are implemented along with FOC to control the PM motor and the results are analyzed. Simulation is carried out in MATLAB Simulink platform and the results are compared.

Current source inverter (CSI) offers key merits of direct output current control, voltage gain operation, current limiting ability, and inherent short-circuit protection. The modulation and control for medium voltage high power application are implemented at low device switching frequency in order to attain high efficiency and to reduce cooling requirements. At low switching frequency operation, the conventional modulation techniques such as space vector modulation (SVM) and sinusoidal pulse width modulation (SPWM) cannot maintain low total harmonic distortion (THD). Synchronous optimal pulse width modulation (SOPWM) is a low frequency modulation technique that offers lower THD without compromising on device switching frequency. However, this technique requires a separate conversion technique for current source converters to incorporate additional switching constraints of CSI. Whereas, the SVM technique directly implements the switching constraints of CSI without any conversion technique and in addition SVM technique provides better dynamic performance compared to low frequency modulation techniques. Hence, the goal of this paper is to propose a hybrid modulation technique that combines the SVM technique and SOPWM technique. Three methods have been proposed for developing hybrid modulation scheme based on SVM and SOPWM. Performance of the proposed hybrid modulation is validated using experimental results.

The dc-link voltage, switching frequency, and modulation strategy all have significant influence on the power losses and output current total harmonic distortion (THD) of a voltage source inverter (VSI). However, there is not a thorough study of the VSI performance in a traction electric drive considering all these parameters present in literature. This paper aims to investigate how the VSI parameters impact the performance of a VSI in a simulated permanent magnet synchronous motor (PMSM) traction drive under various modulation strategies. Analytical methods used to evaluate inverter performance under various modulation strategies are presented to validate the simulation outcomes. A VSI-fed traction electric drive with a 100 kW PMSM is modelled and simulated at several operating points under various modulation strategies and VSI parameters. The considered modulation strategies are sinusoidal pulse width modulation (SPWM), space vector PWM (SVPWM), discontinuous PWM zero (DPWMO), various DPWM variants such as DPWM1, DPWM2, and DPWM3, with VSI dc-link voltages and switching frequencies ranging from 300 to 420 V and 5 to 15 kHz, respectively.

The objective of this paper is to control the speed of Permanent Magnet Synchronous Motor (PMSM) over wide range of speed by consuming minimum time and low cost. Therefore, comparative performance analysis of PMSM on basis of speed regulation has been done in this study. Comparison of two control strategies i.e. Field oriented control (FOC) without sensor less Model Reference Adaptive System (MRAS) and FOC with sensor less MRAS has been carried out. Sensor less speed control of PMSM is achieved by using estimated speed deviation as feedback signal for the PI controller. Performance of the both control strategies has been evaluated in in MATLAB Simulink software. Simulation studies show the response of PMSM speed during various conditions of load and speed variations. Obtained results reveal that the proposed MRAS technique can effectively estimate the speed of rotor with high exactness and torque response is significantly quick as compared to the system without MRAS control system.

Purpose. The main objective of this work is to demonstrate the advantages brought by the use of space vector modulation technique in the direct torque control of the induction motor. To achieve this purpose, two different direct torque control approaches (with space vector modulation) are proposed and studied from a comparative aspect with each other and with the conventional direct torque control. The novelty of this work consists in the employment of an Integral-Proportional (IP) speed controller in the two proposed direct torque control approaches and a more in-depth evaluation for their performance mainly the switching frequency of inverter semiconductor components and motor torque ripples. Methods. Two different direct torque control approaches that use the space vector modulation strategy and/or fuzzy-logic control, are described in detail and simulated with IP speed controller. The simulation experiments are carried out using Matlab/Simulink software and/or fuzzy-logic tools. Results. Practical value. Comparison results show that the two proposed direct torque control structures (with space vector modulation) exhibit a large reduction in torque ripples and can also avoid random variation problem of switching frequency (over a wide range of speed or torque control). On the other hand, the use of IP speed regulator ensured good dynamic performance for the drive system as well as considerably minimized peak overshoot in the speed response. Practically all of these benefits are achieved while retaining the simplicity and the best dynamic characteristics of the classical direct torque control, especially with the modified direct torque control approach in which the design or implementation requires minimal computational effort.

A voltage source inverter with variable frequency and variable voltage is applied for three-phase interior permanent magnet synchronous motor (IPMSM) drive for variable speed application. To obtain the required output voltage in the line side of the inverter a suitable pulse width modulation technique is used. The most prominent PWM techniques are Sinusoidal pulse width modulation (SPWM) and Space vector pulse width modulation (SVPWM). SPWM is simple and easy method to generate pulses for inverter, whereas SVPWM is an accurate method and generate less harmonic distortion compared to SPWM. However there is a lot of complexity involved in calculation of angle and sector as the level increases with SVPWM. To overcome this a similar and easy method known as unified pulse with modulation also know as carrier based space vector pulse width modulation technique(CBSVPWM is described using the concept of effective time. By using this method the inverter output voltage is directly synthesized by the effective times and the voltage modulation task can be greatly simplified. In this paper an IPMSM drive using CBSVPWM is simulated using MATLAB/SIMULINK software and its performance is compared with SPWM by varying modulation index (MI). The simulation study reveals that CBSVPWM simple and easy method which utilizes dc bus voltage more effectively and generates less THD compared to SPWM.

Parallel current source converter (CSC) with multilevel modulation has the advantages to increase the system power range, reliability and improve output quality. In this paper, an interleaved sinusoidal pulse-width modulation (SPWM) for paralleled CSC system is proposed. The gating signals for each CSC are produced by comparing two triangular carriers and three-phase current references directly. Multilevel output can be achieved by simply interleaving the carriers. Comparing to the multilevel space vector modulation (SVM), the proposed method is more straightforward and easier to extend to N-CSC parallel system due to its inherent scalability and modularity. Moreover, lower common-mode voltage (CMV) and circulating current can also be achieved by the proposed SPWM strategy compared to multilevel SVM. The validity and effectiveness of the proposed method are verified on a paralleled CSC system with both simulation and experimental results.

Permanent magnet synchronous motor (PMSM) is the most widely used motor in electric vehicles (EV) due to its high power density and high efficiency. Conventional direct torque control (DTC) is developed to improve the performance of speed response of the PMSM drive but it suffers from higher torque ripples. Therefore a space vector modulation (SVM) based DTC has been developed to enhance the speed response. Due to the use of flux comparator and torque comparator conventional DTC has disadvantages such as higher torque and current ripples at steady state. To improve the performance of PMSM drive a space vector pulse width modulation is used with 3 level NPCI. To improve the performance of 2 level inverter in the PMSM drive is replaced with a neutral point clamped inverter (NPCI). Also, the switching selection strategy of SVM is modified using nearest three space vector pulse width modulation to reduce the total harmonic distortion (THD) in the inverter output. The simulation outcome proves that the SVM technique implementation in DTC for 3 level NPCI yields good performance for PMSM.KeywordsElectric vehicles (EV),voltage source inverter (VSI)Direct torque control (DTC)Neutral point clamped inverter (NPCI)Permanent magnet synchronous motor (PMSM)Space vector modulation (SVM)Total harmonic distortion (THD)

This paper presented a vector controlled drives of permanent Magnet Synchronous Motor (PMSM) by using Proportional-Integral (PI) Speed controller based dSPACE implementation. The concept of vector control is applied to PMSM to obtain linear dynamics similar to that of a DC motor. The model consist of two control loops, hysteresis current controller is used for inner loop current control and PI controller for outer loop speed control. PI speed controller selected due to simplicity compare to fuzzy, neutral etc. to make sure dSPACE DS1103 successfully implemented. The PMSM vector control algorithm for a theoretical basic has been verified by experimental results and created a rapid control prototype environment by using MATLAB/ Simulink and the DS1103 DSP of dSPACE.

The Variable Frequency Drives (VFD) are a common type of controlling the speed of 3-phase induction motors which are based on two control modulation techniques of Voltage Source Inverter: Sinusoidal Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SV-PWM). The SPWM control technique is known as an easier implementation, but the SV-PWM control technique can be distinguished by an easier digital realization and a better utilization of DC bus. All 3-phase PWM inverters produce a total harmonic distortion (THD) on its output, which causes electromechanical and thermal stresses. The aim of this paper is comparing the low order current harmonics while driving an unbalanced 3-phase induction motor (the case of deterioration of the insulation as a result of inter-turn short circuits between few turns of the same phase) using SPWM and SV-PWM two-level 3-phase Voltage Source Inverters (VSI). For this type of unbalanced 3-phase induction motor, the SVPWM and SV-PWM schemes are modeled and simulated using Matlab/Simulink software. A detailed comparative analysis of THD-phase currents is made for both modulation strategies at different switching frequencies while keeping the constant amplitude modulation index.

The efficiency of control systems in permanent magnet synchronous motors (PMSM) is crucial, especially for applications in physiotherapy robots. Previous studies have demonstrated that an open-loop field-oriented control (FOC) driver using BTS7960 outperforms the commonly used electronic speed controller (ESC). This research addresses the challenge of further improving efficiency by employing a closed-loop FOC driver with the BTS7960. The research methodology involves two main stages. First, a PSIM software simulation of a closed-loop FOC using a proportional integral (PI) controller is conducted. The aim is to determine the P and I parameters that result in the smallest settling time, steady-state error, and overshoot in controlling the PMSM motor's rotation per minute (RPM). The second stage involves hardware implementation with the BTS7960, where the PMSM motor RPM is compared under various loads ranging from 10-gram to 60 gram. RPM results from both open-loop and closed-loop configurations are compared. The results show that the closed-loop FOC driver has improved system transient response compared to the previous open-loop FOC driver, notably reducing the settling time from 2.24 seconds to 1.45 seconds for a 60 gram load. Therefore, this research concludes that a closed-loop configuration with well-tuned PI parameters can deliver better performance compared to open-loop methods, as clearly demonstrated.

Permanent magnet synchronous motors (PMSMs) have dominated the motion control industry to the present, and, according to the current trend, there seems to be no end for it Induction motors have always been a minority in the motion control, and they are mainly used in applications, where the field weakening can be utilized to avoid the over-sizing of the drive, which would be the case with PMSMs. There is an increasing trend of using Space vector pulse width modulation (SVPWM) because of their easier digital realization and better dc bus utilization. In this paper both Sinusoidal PWM and space vector PWM feeding a PMSM motor are considered. These techniques are studied through simulation using MATLAB/SIMULENK software and the performance of both the techniques are compared. It is shown through simulation that Space vector PWM effectively utilize dc line voltage and generates reduced THD when compared with Sinusoidal PWM.

One of the main reasons for adopting the field oriented controlled (FOC) induction machine for high performance application is its capability for easy implementation in field weakening. In a sensorless FOC induction machine, the speed estimation in Field Weakening (FW) region and the sensitivity to parameter error of the motor is a major problem. Model Reference Adaptive System (MRAS) approach is one of the best techniques to estimate the rotor speed due to its straight forward stability approach. Space vector pulse width modulated (SVM) voltage source inverter is preferred to feed the FOC induction machine rather than the traditional sinusoidal pulse width modulated (SPWM) inverter due to the full utilization of voltage and current rating of the inverter. In this paper, a sensorless FOC induction machine with MRAS scheme based on sliding mode (SM) technique to estimate the rotor speed in the FW region using SVM fed inverter is modeled. The drive system is simulated by MATLAB/Simulink and the performance of the technique is evaluated by comparing the model with FOC induction machine with sensor using SVM inverter.

Vector control has been widely used to manipulate the permanent magnet synchronous motor (PMSM), in which the traditional double proportional integral (PI) controllers have commonly been utilized. However, it is difficult to set the suitable parameters of PI and maintain the PMSM performance under the different operating regimes. In order to solve these problems, a double closed-loop model predictive control (MPC) strategy based on the vector control has been presented for PMSM in this paper. Firstly, a simplified discrete model of PMSM is established in the d-q coordinate system without considering the interference. Then, the MPC is developed to substitute the PI controller in the speed-loop and the q-axis current-loop, respectively, and a double closed-loop MPC control system is formed. Finally, some case studies are carried out. The simulation and experimental results demonstrate that the presented MPC strategy improves the dynamic and steady-state performance of PMSM.