Control Of Permanent Magnet Synchronous Motor Research Articles

A Finite Control Set Model Predictive Control for Five-Phase PMSMs With Improved DC-Link Utilization

Finite control set model predictive control (FCS-MPC) based on virtual voltage vectors (V3s) is widely studied and applied in five-phase permanent magnet synchronous motor (PMSM) drives. The synthesized V3s can inherently eliminate <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">xy</i> -axes voltages and reduce the number of candidate vectors, which can significantly reduce the computation burden. However, the dc-link utilization is reduced due to the usage of V3s. To address this issue, an FCS-MPC method with improved dc-link utilization is proposed in this article. First, only large vectors are selected to predict the system evolution. The large vector that minimizes cost function is selected, and rescaled using the duty ratio estimation. Then, in order to control the third harmonic currents, three adjacent large vectors are applied to replace the selected vector, and the duty ratios are reassigned. Additionally, zero vectors are replaced with two opposite large vectors to reduce common-mode voltage (CMV). Finally, the proposed FCS-MPC is compared with conventional methods in experiments. Experimental results have verified that the proposed method can improve the dc-link utilization, and keep the superiorities of low CMV and low computation burden.

Enhanced Predictive Model Based Deadbeat Control for PMSM Drives Using Exponential Extended State Observer

In order to improve robustness and dynamic tracking performance, this article proposes a deadbeat control method based on an enhanced predictive model and an exponential extended state observer (EDB-EESO). By incorporating parameter mismatches and load perturbation as lumped disturbance, extended state-space realizations of permanent magnet synchronous motor (PMSM) speed and stator current mathematical model are presented. To achieve higher robustness under the disturbance, the exponential extended state observer (EESO) is proposed based on the extended state-space realizations. Combining the EESO, the enhanced predictive model is designed to improve overshoot and settling time caused by the system inertial link. To eliminate the effect of time delay, a two-step predictive control method is adopted in the enhanced predictive model. Furthermore, the cost function of EDB-EESO is evaluated by utilizing the deadbeat control method and the stability of EDB-EESO is proved. The experimental results validate the strong robustness and excellent dynamic tracking performance of EDB-EESO in PMSM drives compared with conventional methods.

A Single-Current-Regulator Flux-Weakening Control for PMSM Under Square-Wave Mode With Wider Operation Range

In the rail transit traction system, the traction motor will operate under square-wave mode at high speed. The voltage amplitude will be fixed under the square-wave mode, while only the voltage angle can be regulated. The single-current-regulator (SCR) method is a good choice to regulate the voltage angle while keeping the voltage amplitude constant. However, the existing SCR methods cannot work stably in the whole flux-weakening area of the infinite speed system. The single <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$d$ </tex-math></inline-formula> -axis current regulator-regulates <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$q$ </tex-math></inline-formula> -axis voltage (SDCR-RQV) method that can provide a wider operation range is proposed in this article. SDCR-RQV is qualified for the permanent magnet synchronous motor (PMSM) used in rail transit, whether it is a finite speed system or an infinite speed system. The proposed method is analyzed in detail and verified by simulation and experimental results.

Integral Sliding Mode Control Based Deadbeat Predictive Current Control for PMSM Drives With Disturbance Rejection

To promote the control performance of the modern high-precision permanent-magnet synchronous motor (PMSM) system on the existence of the time-delay and parameter mismatch, an improved deadbeat predictive current control (DPCC) method is proposed in this article. First, the conventional DPCC method considering the time-delay compensation is introduced. Along with this method, the negative influence on the control performance when the parameter mismatch occur is analyzed mathematically. Afterward, this article proposes a novel compensation scheme based on the integral sliding mode control (ISMC) theory for disturbance elimination. This proposed method incorporates the disturbance rejection term in the main control loop, which avoids the side effects of the traditional parallel external observer-based compensation method. The convergence of this disturbance rejection design is also proved. Meanwhile, the procedure of the ISMC-based DPCC method in digital implementation is illustrated and the resulting problems are discussed and solved. Furthermore, the chattering problem caused by the signum function is significantly suppressed by introducing the improved super-twisting algorithm combined method. Finally, experimental results confirm the validity of the proposed ISMC-based DPCC controller.

Sensorless Control of PMSM in Low Speed Region Using HF Pulse Signal Injection Method

Abstract The sensorless control of the permanent magnet synchronous motor (PMSM) has attracted wide attention due to its economic and safety benefits. A fast and high-precision rotor-position estimation is necessary for the implementation of sensorless control. In low-speed region, high frequency (HF) signal injection methods are mostly adopted. They suffer to bandwidth deterioration as some digital filters must be included in the current feedback loop or the speed observation signal processing. The HF signal injection method based on the injection of voltage pulses is presented in this paper together with its implementation in MATLAB/Simulink. The method is based on the injection of voltage pulses where injection itself is separated from the motor control algorithm. The simulation results show that the proposed method has good dynamic performance for the sensorless control of PMSM.

회전자의 과도한 온도 상승을 줄이는 PI형 PMSM 제어기 설계

This study considers the problem of designing a PI-type PMSM (permanent magnet synchronous motor) controller, which can prevent excessive temperature rise in the rotor. The problem was formulated as a nonlinear optimization problem, considering that the flux linkage of a PMSM depends on the rotor temperature value and can be estimated using the voltage input value. This study proposes a design procedure for solving the nonlinear optimization problem using the particle swarm optimization (PSO) algorithm, a metaheuristic search algorithm. Simulation studies using a practical PMSM model verified that the design problem can be successfully solved using a metaheuristic search algorithm.

An Improved Deadbeat Current Controller of PMSM Based on Bilinear Discretization

Based on the bilinear discretization mathematical model of permanent magnet synchronous motor (PMSM), an improved incremental deadbeat current prediction control algorithm is proposed. Aiming at the system instability caused by the forward Euler discretization method, this paper combines the deadbeat current prediction control and the improved bilinear discretization method to improve the system stability. Further, the proposed controller considers the two-beat delay of a digital system to make the mathematical model more accurate. Moreover, the proposed bilinear discretization predictive current controller is not affected by the permanent magnet flux of the motor. Then, the system stability conditions of the proposed controller are analyzed. The simulation and experimental results verify the feasibility and effectiveness of the proposed method.

Grey‐prediction‐based double model predictive control strategy for the speed and current control of permanent magnet synchronous motor

AbstractTo solve the problems of slow response speed of the permanent magnet synchronous motor (PMSM) system when the external disturbance occurs and the poor disturbance rejection performance, a double model predictive control (MPC) strategy for PMSM to control speed and current is proposed in this paper. Further, in order to improve the dynamic performance and disturbance rejection performance of PMSM control system, a grey prediction is introduced, and then a grey‐prediction‐based double MPC strategy is proposed. To be specific, firstly, the mathematical model of PMSM is established under the dq coordinate system, and the traditional control strategy (outer speed loop PI controller and inner current loop deadbeat prediction controller) is elaborated. Secondly, we propose the double MPC strategy where MPC controller is used in the outer speed loop and deadbeat prediction controller is used in the inner current loop. Finally, the grey‐prediction‐based double MPC strategy is proposed where MPC is combined with grey prediction to improve the dynamic performance in the inner current loop. By comparing the traditional control strategy with the double MPC and the grey‐prediction‐based double MPC strategy, the simulation results show that the double MPC and the grey‐prediction‐based double MPC system have no overshoot and the grey‐prediction‐based double MPC system has better steady‐state performance, faster dynamic response and stronger disturbance rejection performance, which proves the effectiveness of the proposed strategy.

Model Predictive Control and Higher Order Sliding Mode Control for Optimized and Robust Control of PMSM

Model Predictive Control (MPC) applied to Permanent Magnet Synchronous Motors (PMSM) based drives is being researched recently. Practical drive systems have non-linarites like saturation, not-exact decoupling of d and q axes fluxes, etc. Further there are disturbances also. MPC guarantees the robust stability and performance. The strategy is used for decoupled current control of PMSM. Additionally optimized control voltage vector is calculated to yield best energy efficiency. This paper proposes MPC for current loop of the drive. In order to have simplicity in the entire system, the outer speed loop is controlled by Higher Order Sliding Mode Control (HOSMC). Super Twisting Algorithm (STA) is used for reduction in the chattering. Simulations show that the proposed control skills has superior performance compare to conventional PI control algorithm.

A STA Current-Constrained Control for PMSM Speed Regulation System with Function Disturbance Observer

The non-cascade permanent magnet synchronous motor control system has the advantages of simple structure and less adjustable parameters, but the non-cascade structure needs to solve the problem of over-current protection. In this paper, a current constrained control method is used to limit the starting current to a safe range. At the same time, to ensure the robustness and rapidity of the system, a super twist current constraint controller (CCSTA) is generated by combining super twist algorithm (STA) with current constraint control; Considering the diversity of internal and external disturbances, a functional disturbance observer (FDOB) is proposed to compensate the matched and unmatched disturbances, which further improves the robustness of the system.

Overmodulation Strategy for Voltage Source Inverter With a Single DC-Link Current Sensor

With a single shunt resistor, it is possible to sense the phase currents, although some dead regions exist around vertices of the voltage hexagon. In this article, an overmodulation method is presented for such single current shunt inverters. Regions near vertices of voltage hexagon are defined as holding regions, and the rest are defined as linear regions. The overmodulation strategy is developed based on the Fourier analysis: The magnitude of reference voltage determines the arc radius in the linear region and the holding angle of the holding region. By adjusting either the arc radius or the holding angle, the desired modulation index (MI) can be output. It is particularly useful for low-cost inverters, since it is implemented with an additional look-up table for induction motor or permanent magnet synchronous motor control. The linearity is maintained between the reference MI and its output MI until it reaches to the maximum, 12-step operation. In addition, the technique provides the seamless transition from space vector modulation to 12-step operation. The effectiveness is evidenced by the experimental results.

Super-Twisting Hybrid Control for Ship-Borne PMSM

In the field of ship-borne PMSM, there exists the sea wave fluctuations, external disturbances thus model uncertainties are always challenging the control design of ship-borne permanent magnet synchronous motors (PMSMs). To deal with this problem, a super-twisting extended state observer (SESO) is used in this paper to observe state variables accurately. Moreover, to solve the phase delay problem in active disturbance rejection control (ADRC), Taylor’s formula-based tracking differentiator (TTD) is applied in the proposed hybrid control strategy. With appropriate compensate of disturbance, denoted as super-twisting hybrid control, the controlled position signal can follow the reference with small tracking errors, also with improved dynamic performance. Simulation results show that the proposed super-twisting hybrid control has the better anti-disturbance and tracking performance compared with the traditional ADRC. Lastly, semi-physical experimental results further validate the effectiveness of the control strategy for ship-borne PMSMs.

Switched PI Control Based MRAS for Sensorless Control of PMSM Drives Using Fuzzy-Logic-Controller

With the use of sensorless control strategy, mechanical position sensors can be removed from the gearbox, so as to decrease the maintenance costs and enhance the system robustness. In this paper, a switching PI control based model reference adaptive system (MRAS) observer using Fuzzy-Logic-Controller (FLC) is introduced for sensorless control of permanent magnet synchronous motor (PMSM) drives. The main work and innovation of this paper include: 1) A disturbance observer based voltage compensation method is proposed to solve the problems of voltage distortion in voltage source inverter (VSI) fed PMSM systems. 2) A double closed-loop FLC is designed for speed and current control. The response performance of speed regulation and the accuracy of the command voltage are improved, and the difficulty of manual adjustment of control parameters is avoided. 3) A sensorless control strategy of a switching PI control based MRAS observer is proposed for stator resistance tracking. By setting different thresholds, the proposed MRAS observer can choose the appropriate PI adaptive mechanism based on the amplitude of the current error variable, which can improve the accuracy of resistance estimation and improve the dynamic performance of sensorless control. 4) The experimental results are given to verify the availability of the proposed scheme.

A Simple and Robust Model Predictive Current Control of PMSM Using Stator Current Predictor and Target-Oriented Cost Function

Model predictive current control of permanent magnet synchronous motor(PMSM), which inherits from the vector control framework, has become a promising control strategy because of its simple structure and fast dynamic response. In order to protect the stator current prediction model from the influence of mismatched parameters, a simple and robust predictive current control with stator current predictor and target-oriented cost function (abbreviated as SCP-TOSF-PCC) is proposed in this paper. The feedback mechanism is introduced into the prediction equation in the discrete domain, and its design principle and stability analysis are also described in detail. In addition, different from the traditional cost function design method which is constructed by the tracking errors of stator current, this paper proposes a direct target-oriented cost function, which takes the average pulsations of d-axis current and q-axis current as the judge index. The design method of this cost function takes into account the influence of historical values on the voltage vector selection. The experimental results show that compared with the traditional methods, the proposed method has better dynamic, steady-state and robust performance.

Novel Fast Terminal Reaching Law Based Composite Speed Control of PMSM Drive System

In this paper, a novel fast terminal sliding mode reaching law (FTSMRL) based sliding mode control (SMC) is proposed to improve the speed dynamic performance of the permanent magnet synchronous motor (PMSM) and drive. The proposed FTSMRL contains two power terms, which can take the leading role in the SMC process, when sliding state is near or far from the selected sliding trajectory. The proposed SMC based FTSMRL can not only suppress the chattering phenomenon effectively, but also improve the reaching velocity of the sliding state variable. In order to further improve the system disturbance rejection ability of the control system, an extended state observer (ESO) is also developed in this work. The proposed observer estimates the disturbances and inputs the signal to a feed-forward compensation controller considering the chattering phenomenon caused by the high switching gain. The proposed method has been fully confirmed by mathematical stability check, numerical analysis and experiments, separately.

Fault Diagnosis and Fault-Tolerant Control of PMSM Drives–State of the Art and Future Challenges

The issues of monitoring and fault diagnosis of drives with permanent magnet synchronous motors (PMSM) are currently very topical due to the increasing use of these drives in safety-critical devices. Every year, more and more articles on this subject are published. Therefore, the aim of this article is to update the overview of diagnostic methods and techniques for PMSM drives. Each of the main chapters of the article focuses on a specific element of the drive system (motor, power converter, measuring sensors), with particular emphasis on the components of the motor (stator windings, magnets, bearings, rotor). The main sections on PMSM fault diagnosis are divided according to the type of methods used to obtain the symptoms of the damage. In addition, a review of methods using the analysis of control structure signals for the diagnosis of damage to a vector-controlled motor is presented, as well as the latest achievements of researchers in the field of shallow and deep neural networks for the detection and classification of PMSM drives failures. Based on the presented literature analyses, some development trends and challenges related to the development of diagnostics and fault-tolerant control of PMSM drives are discussed in the conclusion part.

Practical discontinuous tracking control for a permanent magnet synchronous motor.

In this paper, the practical discontinuous control algorithm is used in the tracking controller design for a permanent magnet synchronous motor (PMSM). Although the theory of discontinuous control has been studied intensely, it is seldom applied to the actual systems, which encourages us to spread the discontinuous control algorithm to motor control. Due to the constraints of physical conditions, the input of the system is limited. Hence, we design the practical discontinuous control algorithm for PMSM with input saturation. To achieve the tracking control of PMSM, we define the error variables of the tracking control, and the sliding mode control method is introduced to complete the design of the discontinuous controller. Based on the Lyapunov stability theory, the error variables are guaranteed to converge to zero asymptotically, and the tracking control of the system is realized. Finally, the validity of the proposed control method is verified by a simulation example and the experimental platform.

A Novel Method for Diagnosing Demagnetization Fault in PMSM Using Toroidal-Yoke-Type Search Coil

Demagnetization fault in a permanent magnet synchronous motor (PMSM) degrades its performance and may cause serious catastrophes. Fault localization technique can improve the reliability and safety of PMSM and provide important information for developing operation and maintenance strategies. Thus, a fault localization method is so important. Mainstream is a common method that uses search coil installed on every stator tooth to diagnose fault location. Due to the use of a large number of search coils, the method is limited in terms of invasiveness, implementation cost, and installation. Moreover, the method can only diagnose the fault location in PMSM with one demagnetized permanent magnet (PM). This article proposes a novel method which can detect the specific location of demagnetized PMs in PMSM with any types of demagnetization faults. The method only needs three additional toroidal yoke coils wound around the stator yoke. Toroidal yoke coils are used to measure the back electromotive force (EMF). The demagnetization fault localization signals (DFLSs) are produced by basic calculation of the output signals of three search coils. The DFLSs are partitioned according to the electrical period. The location of demagnetization fault can be diagnosed through analyzing each electric period waveform of DFLSs. First, the arrangement of toroidal-yoke-type search coil and the construction method of DFLSs are introduced. Second, a partitioned analytical model of DFLSs is developed. Third, waveforms in one electric period of DFLSs under preset fault types are investigated. Finally, the method for diagnosing demagnetization fault in PMSM is proposed. The simulation and experimental results justify the precision of the proposed search coil which shows the maximum error of back EMF to be 4.1%. It also shows the ability of the method to locate demagnetized PMs when the demagnetization severity (the ratio of the change in coercive force of PM to the normal coercive force) is 10%. This study provides a new method for diagnosing demagnetization fault, as well as provides a significant reference for fault post-processing and fault-tolerant control of PMSM.

Hybrid flux predictor‐based predictive flux control of permanent magnet synchronous motor drives

In the field of a model predictive control of a permanent magnet synchronous motor (PMSM), the predictive flux control (PFC) has received great attention, which only takes the stator flux vector as the control variable instead of the electromagnetic torque and the stator flux amplitude. Because PFC does not involve the cumbersome setting of weight factors, it is a promising control algorithm. However, the prediction of the stator flux vector depends on motor parameters, which inevitably reduces the robustness of the control system. In order to solve this problem, this paper proposes a hybrid flux predictor-based predictive flux control of PMSM drives. The proposed stator flux predictor combines the voltage prediction model and the current prediction model, and the proportional–integral regulator is utilised to control the switching between the two prediction models. Experimental results show that the proposed algorithm has better dynamic, steady-state and robust performances than the traditional predictive flux control.

Novel tilt integral sliding mode controller and observer design for sensorless speed control of a permanent magnet synchronous motor

PurposeThis study aims to design and implement a novel tilt integral sliding mode controller and observer for sensorless speed control of a permanent magnet synchronous motor (PMSM).Design/methodology/approachA control strategy combining the tilt integral derivative (TID) with sliding mode control (SMC) is proposed to determine the tilt integral sliding mode manifold. Using this manifold, tilt integral sliding mode controller (TISMC) and observer (TISMO) are designed. The stabilities are verified by using Lyapunov method. To prove the effectiveness and robustness of proposed methods, sensorless speed control of PMSM is performed for various operating conditions such as constant and variable speed references, load disturbance injection, parameter perturbation, whereas sensor noises are not taken into account. The performance of proposed method is compared with TID controller, proportional integral derivative controller and conventional SMO.FindingsSimulation results demonstrate that TISMC and TISMO have better performance in all operating conditions. They are robust against parameter uncertainties and disturbances. TISM based sensorless control of PMSM is well guaranteed with superior performance.Originality/valueThe proposed method has not been tackled in the literature. By combining TID and SMC, novel tilt integral sliding manifold is presented and used in designing of the controller and observer. It is proven by Lyapunov method that errors converge to zero.