Inverter-fed Permanent Magnet Synchronous Motor Research Articles

Flatness-based control in successive loops for VSI-fed PM synchronous motors and induction motors

Electric traction systems consisting of inverter controlled three-phase motors are widely used in electric vehicles. In this article the control problem for the nonlinear dynamics of Voltage Source Inverter-fed synchronous and asynchronous motors is solved with the use of a flatness-based control approach which is implemented in successive loops. The state–space model of these systems is separated into a series of subsystems, which are connected between them in cascading loops. Each one of these subsystems can be viewed independently as a differentially flat system and control about it can be performed with inversion of its dynamics as in the case of input–output linearised flat systems. In this chain of i = 1 , 2 , … , N subsystems, the state variables of the subsequent (i + 1th) subsystem become virtual control inputs for the preceding (ith) subsystem, and so on. In turn, exogenous control inputs are applied to the last subsystem and are computed by tracing backwards the virtual control inputs of the preceding N−1 subsystems. The whole control method is implemented in successive loops and its global stability properties are also proven through Lyapunov stability analysis. The validity of the control method is confirmed in two case studies: (a) control of a Voltage Source Inverter-fed Permanent Magnet Synchronous Motor (VSI-fed PMSM), (ii) control of a Voltage Source Inverter-fed Induction Motor (VSI-fed IM).

A nonlinear optimal control approach for voltage source inverter-fed three-phase PMSMs

PurposeVoltage source inverter-fed permanent magnet synchronous motors (VSI-PMSMs) are widely used in industrial actuation and mechatronic systems in water pumping stations, as well as in the traction of transportation systems (such as electric vehicles and electric trains or ships with electric propulsion). The dynamic model of VSI-PMSMs is multivariable and exhibits complicated nonlinear dynamics. The inverters’ currents, which are generated through a pulsewidth modulation process, are used to control the stator currents of the PMSM, which in turn control the rotational speed of this electric machine. So far, several nonlinear control schemes for VSI-PMSMs have been developed, having as primary objectives the precise tracking of setpoints by the system’s state variables and robustness to parametric changes or external perturbations. However, little has been done for the solution of the associated nonlinear optimal control problem. The purpose of this study/paper is to provide a novel nonlinear optimal control method for VSI-fed three-phase PMSMs.Design/methodology/approachThe present article proposes a nonlinear optimal control approach for VSI-PMSMs. The nonlinear dynamic model of VSI-PMSMs undergoes approximate linearization around a temporary operating point, which is recomputed at each iteration of the control method. This temporary operating point is defined by the present value of the voltage source inverter-fed PMSM state vector and by the last sampled value of the motor’s control input vector. The linearization relies on Taylor series expansion and the calculation of the system’s Jacobian matrices. For the approximately linearized model of the voltage source inverter-fed PMSM, an H-infinity feedback controller is designed. For the computation of the controller’s feedback gains, an algebraic Riccati equation is iteratively solved at each time-step of the control method. The global asymptotic stability properties of the control method are proven through Lyapunov analysis. Finally, to implement state estimation-based control for this system, the H-infinity Kalman filter is proposed as a state observer. The proposed control method achieves fast and accurate tracking of the reference setpoints of the VSI-fed PMSM under moderate variations of the control inputs.FindingsThe proposed H-infinity controller provides the solution to the optimal control problem for the VSI-PMSM system under model uncertainty and external perturbations. Actually, this controller represents a min–max differential game taking place between the control inputs, which try to minimize a cost function that contains a quadratic term of the state vector’s tracking error, the model uncertainty, and exogenous disturbance terms, which try to maximize this cost function. To select the feedback gains of the stabilizing feedback controller, an algebraic Riccati equation is repetitively solved at each time-step of the control algorithm. To analyze the stability properties of the control scheme, the Lyapunov method is used. It is proven that the VSI-PMSM loop has the H-infinity tracking performance property, which signifies robustness against model uncertainty and disturbances. Moreover, under moderate conditions, the global asymptotic stability properties of this control scheme are proven. The proposed control method achieves fast tracking of reference setpoints by the VSI-PMSM state variables, while keeping also moderate the variations of the control inputs. The latter property indicates that energy consumption by the VSI-PMSM control loop can be minimized.Practical implicationsThe proposed nonlinear optimal control method for the VSI-PMSM system exhibits several advantages: Comparing to global linearization-based control methods, such as Lie algebra-based control or differential flatness theory-based control, the nonlinear optimal control scheme avoids complicated state variable transformations (diffeomorphisms). Besides, its control inputs are applied directly to the initial nonlinear model of the VSI-PMSM system, and thus inverse transformations and the related singularity problems are also avoided. Compared with backstepping control, the nonlinear optimal control scheme does not require the state-space description of the controlled system to be found in the triangular (backstepping integral) form. Compared with sliding-mode control, there is no need to define in an often intuitive manner the sliding surfaces of the controlled system. Finally, compared with local model-based control, the article’s nonlinear optimal control method avoids linearization around multiple operating points and does not need the solution of multiple Riccati equations or LMIs. As a result of this, the nonlinear optimal control method requires less computational effort.Social implicationsVoltage source inverter-fed permanent magnet synchronous motors (VSI-PMSMs) are widely used in industrial actuation and mechatronic systems in water pumping stations, as well as in the traction of transportation systems (such as electric vehicles and electric trains or ships with electric propulsion), The solution of the associated nonlinear control problem enables reliable and precise functioning of VSI-fd PMSMs. This in turn has a positive impact in all related industrial applications and in tasks of electric traction and propulsion where VSI-fed PMSMs are used. It is particularly important for electric transportation systems and for the wide use of electric vehicles as expected by green policies which aim at deploying electromotion and at achieving the Net Zero objective.Originality/valueUnlike past approaches, in the new nonlinear optimal control method, linearization is performed around a temporary operating point, which is defined by the present value of the system’s state vector and by the last sampled value of the control input vector and not at points that belong to the desirable trajectory (setpoints). Besides, the Riccati equation, which is used for computing the feedback gains of the controller, is new, as is the global stability proof for this control method. Comparing with nonlinear model predictive control, which is a popular approach for treating the optimal control problem in industry, the new nonlinear optimal (H-infinity) control scheme is of proven global stability, and the convergence of its iterative search for the optimum does not depend on initial conditions and trials with multiple sets of controller parameters. It is also noteworthy that the nonlinear optimal control method is applicable to a wider class of dynamical systems than approaches based on the solution of state-dependent Riccati equations (SDRE). The SDRE approaches can be applied only to dynamical systems that can be transformed to the linear parameter varying form. Besides, the nonlinear optimal control method performs better than nonlinear optimal control schemes which use approximation of the solution of the Hamilton–Jacobi–Bellman equation by Galerkin series expansions.

A Simplified Model Predictive Voltage Control for Three-Phase Four-Switch Inverter-Fed PMSM Drives With Capacitor Voltage Offset Suppression and Current Ripple Reduction

This article proposes a simplified model predictive voltage control (SMPVC) method without weighting factors for three-phase four-switch inverter-fed permanent magnet synchronous motor drives to suppress the capacitor voltage offset and reduce the current ripple. In this article, the control of electromagnetic torque and magnetic flux in the model predictive torque control is transformed into the control of the voltage vector, and the capacitor voltage offset is suppressed by injecting dc component obtained by an adaptive notch filter into the phase current. On the basis, the voltage vector is taken as the only control term in cost function without the weighting factors to suppress capacitor voltage offset, thus simplifying the calculation amount in cost function. Then the simplified voltage vector synthesis method is presented to synthesize the effective voltage vector to reduce the current ripple. Using the simple sector division, the switching sequence of the voltage vector can be determined quickly. The effectiveness of the proposed SMPVC method is validated by the simulation and experiment.

Analysis and Reduction of Current and Voltage Ripple in DC Link for Three-Level NPC Inverter-Fed Dual Three-Phase Motor Drives

In this article, switching strategies for dc-link current and voltage ripple reduction have been studied. The considered topology is a neutral-point clamped three-level (NPC-3L) inverter feeding a dual three-phase permanent-magnet synchronous motor (PMSM). The mechanisms of dc-link current and voltage ripple generation in an NPC-3L inverter-fed PMSM drive are analyzed in detail. Then, a two-step collaborative switching strategy is proposed, where the optimum switching sequences, including opposite small vectors, are applied in the two inverters collaboratively. Furthermore, the switching vectors of two inverters are rearranged in the sequence of their corresponding dc-link capacitor currents so that the overlapping of their peaks is avoided. Consequently, both the voltage ripple and current ripple in the dc-link capacitors are mitigated with the proposed two-step collaborative switching strategy. For the midpoint voltage of the NPC-3L inverter, the amplitude of fluctuation is reduced under low modulation index operation, while the high-frequency harmonic components are mitigated under high modulation index operation. The experimental results are given to verify the validity of the theoretical analysis and the proposed switching strategy.

Single-stage PV-powered boost inverter-fed permanent-magnet synchronous motor-driven water-pumping system

Abstract In this paper, a photovoltaic (PV) fed boost inverter-based permanent-magnet synchronous motor (PMSM)-driven water-pumping system for stand-alone applications is proposed. The proposed system comprises PV panel, six switches, three inductors (L), three capacitors (C) and a water pump. In this work, the boost inverter is designed with a gain of two and thereby the direct current input required to run the motor is considerably reduced. Hence, the size of the system is reduced. The voltage gain factor depends upon the placement of the L and C components and their values. The speed reference is generated using a perturb and observe maximum power point tracking algorithm. Vector control is employed to control a boost inverter-fed PMSM drive. The proposed system is simulated using a MATLAB®/Simulink® environment and experimental validation is performed on a PMSM laboratory prototype using a field programmable gate array controller. The simulation and experimental results demonstrate the effectiveness of the proposed system.

Direct torque control based on second order sliding mode controller for three-level inverter-fed permanent magnet synchronous motor: comparative study

Introduction. The permanent magnet synchronous motor (PMSM) has occupied a large area in the industry because of various benefits such as its simple structure, reduced moment of inertia, and quick dynamic response. Several control techniques have been introduced for the control of the PMSM. The direct torque control strategy associated to three-level clamped neutral point inverter has been proven its effectiveness to solve problems of ripples in both electromagnetic torque and stator flux with regard to its significant advantages in terms of fast torque response. Purpose. The use of a proportional integral speed controller in the direct torque control model results in a loss of decoupling with regard to parameter fluctuations (such as a change in stator resistance value induced by an increase in motor temperature), which is a significant drawback for this method at high running speeds. Methods. That is way a second order sliding mode controller based on the super twisting algorithm (STA) was implemented instead of PI controller to achieve a decoupled control with higher performance and to insure stability while dealing with parameter changes and external disturbances. Results. The simulation results carried out using MATLAB/Simulink software show that the model of direct torque control based on a three-level inverter-fed permanent magnet synchronous motor drive has better performance with second order sliding mode speed controller than the proportional integral controller. Through the response characteristics we see greater performance in terms of response time and reference tracking without overshoots. Decoupling, stability, and convergence toward equilibrium are all guaranteed.

Real-Time Detection of Incipient Inter-Turn Short Circuit and Sensor Faults in Permanent Magnet Synchronous Motor Drives Based on Generalized Likelihood Ratio Test and Structural Analysis.

This paper presents a robust model-based technique to detect multiple faults in permanent magnet synchronous motors (PMSMs), namely inter-turn short circuit (ITSC) and encoder faults. The proposed model is based on a structural analysis, which uses the dynamic mathematical model of a PMSM in an frame to evaluate the system’s structural model in matrix form. The just-determined and over-determined parts of the system are separated by a Dulmage–Mendelsohn decomposition tool. Subsequently, the analytical redundant relations obtained using the over-determined part of the system are used to form smaller redundant testable sub-models based on the number of defined fault terms. Furthermore, four structured residuals are designed based on the acquired redundant sub-models to detect measurement faults in the encoder and ITSC faults, which are applied in different levels of each phase winding. The effectiveness of the proposed detection method is validated by an in-house test setup of an inverter-fed PMSM, where ITSC and encoder faults are applied to the system in different time intervals using controllable relays. Finally, a statistical detector, namely a generalized likelihood ratio test algorithm, is implemented in the decision-making diagnostic system resulting in the ability to detect ITSC faults as small as one single short-circuited turn out of 102, i.e., when less than 1% of the PMSM phase winding is short-circuited.

Optimal Design of an Inverter-Fed PMSM for a Brake System Considering Variation in Motor Control Parameters and Input Voltage

This study proposes an optimal design approach for an inverter-fed permanent magnet synchronous motor (PMSM) considering the variation in motor control parameters and input voltage (inverter output voltage), which vary with respect to the temperature and loading conditions, in an integrated brake system. In an integrated brake system, a quick response to load changes is crucial. Therefore, in this study, to consider the fluctuation in control variables and input voltage, the motor control parameters and input voltage were first calculated according to the operating temperature and loading condition. Subsequently, based on the calculated conditions and the approximated motor input voltage and control parameters, the objective functions corresponding to motor characteristics in transient and steady states were formulated using design-of-experiment (DOE), the moving least square method (MLSM), and the finite element method (FEM). Finally, the optimal design was performed using the genetic algorithm (GA). The validity of the proposed optimal design approach was verified by comparing its optimization results with the FEM analysis results. Thus, it was confirmed that a motor can be designed for an integrated brake system by considering the motor control parameters and motor input voltage, which vary with the driving conditions.

A Reference Voltage Self-Correction Method for Capacitor Voltage Offset Suppression of Three-Phase Four-Switch Inverter-Fed PMSM Drives

This paper proposes a capacitor voltage offset suppression method based on reference voltage self-correction for a three-phase four-switch (TPFS) inverter-fed permanent magnet synchronous motor (PMSM) drive system to improve the motor control performance. Firstly, the αβ-axis reference voltage deviation caused by capacitor voltage offset is analyzed, and the relationship between the voltage to be compensated and the offset is obtained. Then, the capacitor voltage offset is calculated according to the motor speed, rotor position, current vector amplitude, and capacitance on the capacitor bridge arm of the TPFS inverter. Finally, the reference voltage is corrected according to the voltage to be compensated and the capacitor voltage offset. This method is simple and easy to implement, and there is no need to add voltage sensors or filters in the system to extract the capacitor voltage offset, and there is no complex parameter adjustment. The effectiveness of the proposed method is verified by experiments on a 20 kW interior permanent magnet synchronous motor.

Performance Analysis of Multi-Level Inverter-Fed Position Sensorless PMSM Drive Using Modified MPTC

In this article, the performance of multilevel inverter-fed position sensorless permanent magnet synchronous motor (PMSM) drive is analyzed using modified model predictive torque control (MPTC) method using two-level and three-level inverters, respectively. The MPTC method helps to control electromagnetic torque directly, which is not possible in model predictive current control, whereas the conventional model predictive torque and flux control method requires weighing factors that are similar to PI controllers used in field-oriented control or direct torque and flux control method. To simplify the control structure, most of the researchers are looking forward to weighing factorless predictive control strategies. The multilevel inverters required complex control algorithms such as space vector modulation. However, the model predictive control methods made it simple by using an embedded control structure. Furthermore, position sensorless control strategies are much needed because speed sensors are much prone to failures. Therefore, in this article, a model reference adaptive system (MRAS)–based speed sensorless approach is used to eliminate the requirement of a position sensor. The proposed multilevel inverter-fed position sensorless PMSM drive using modified MPTC is simulated in MATLAB/SIMULINK environment under different operating conditions such as under no-load, load, and change in speed. The simulation results are validated with the experimental results.

Surrogate Models for Design and Optimization of Inverter-Fed Synchronous Motor Drives

Design and optimization problems typically require running thousands of motor simulations which can take several hours, if not days. To overcome this bottleneck, surrogate models are often used in engineering design to expedite the process. When inverter-fed motor drives are involved, the cost of generating a finite element (FE) database from a pulsewidth modulated (PWM) current simulations to fit such models can be prohibitive. This article compares an ensemble of surrogate models of synchronous motors generated with sinusoidal and PWM stator excitations, in terms of computational burden and performance. The main contribution resides in showing whether computational resources can be saved with sinusoidal excitation models without compromising the optimization results of a real inverter-fed permanent magnet synchronous motor design.

Current-Based Open-Circuit Fault Diagnosis for PMSM Drives With Model Predictive Control

Fault diagnosis is currently considered a crucial method to enhance the reliability of permanent magnet synchronous motor (PMSM) drives. In this article, an open-circuit fault (OCF) diagnosis method of a voltage source inverter-fed PMSM with model predictive control is proposed. The developed approach mainly consists of fault detection and localization. Besides, the normalized cost function variation is designed as a fault detection indicator according to the impact of OCFs on current signatures. It can not only monitor drive system conditions, but also discriminate fault categories. Afterward, the polarities of normalized αβ-current average values and phase angles of residual current vectors are utilized to locate the exact faulty switch in each fault type. Consequently, a total of 21 possible combinations of faulty switches can be correctly detected and located. Finally, the effectiveness in fault diagnoses and the robustness against operating point variations are verified by the experimental results.

Optimal Vector Sequences for Simultaneous Reduction of the Switching Loss, Zero-Sequence Circulating Current, and Torque Ripple in Two Parallel Interleaved Inverter-Fed PMSM Drives

The two-parallel interleaved converters system is essentially a multilevel converter and introduces more vector redundancies than a single converter, leaving a large space for vector sequences optimization for the simultaneous optimization of crucial indicators. However, the vector redundancies have not been fully explored by previous studies to achieve multiple crucial indicators optimization. This article aims to obtain high efficiency and low torque ripples for the two-parallel interleaved converters-fed permanent-magnet synchronous motor (PMSM), which are dominantly affected by the switching loss, zero-sequence circulating current (ZSCC), and torque ripples. First, given the vector redundancies, this article explores the available vector sequences according to switching times, the minimal torque ripple, and ZSCC with a priority of the switching times. The resultant vector sequences split each 60° sector into eight subsectors, but each subsector has redundant vector sequences. Then, this article further quantitatively analyzes the torque ripple and ZSCC of the redundant vector sequences in the subsectors, based on which each subsector applies an optimal vector sequence. Despite the complexity of the divisions of the subsectors, this article proposes a simple carrier-based modulation scheme and the implementation of the proposed optimal vector sequences amounts to corresponding common-mode voltage (CMV) injections into the references, which only require a simple logic judgment. The theoretical analysis confirms that the proposed method yields smaller torque ripples, ZSCCs, and switching losses than existing pulsewidth modulation (PWM) schemes over the whole modulation indices. Finally, the experimental results further verify the theoretical analysis and the effectiveness of the proposed strategy.

Model predictive control with fixed weighting factor for three‐phase four‐switch inverter‐fed PMSM drives considering capacitor voltage offset suppression

This study proposes a model predictive control (MPC) method with a fixed weighting factor for three-phase four-switch inverter-fed permanent magnet synchronous motor drives to suppress the capacitor voltage offset. The prediction model of the capacitor voltage difference is obtained based on the relationship between capacitor voltage and phase current. Then by analysing the relationship between basic voltage vector, electromagnetic torque and flux amplitude, the control of electromagnetic torque and flux in the model predictive torque control is transformed into the control of the voltage vector. The dimension of the capacitor voltage difference is the same as that of the voltage vector, hence the cost function with the fixed weighting factor is defined with the consideration of the capacitor voltage offset suppression. The effectiveness of the proposed MPC method is validated by the simulation and experiment.

Modified LUT-based DTC of NPC 3-Level Inverter fed Sensorless IPMSM Drive with DC Link Voltage Balance

In the proposed work, a modified look-up table-based direct torque control (DTC) scheme is reported for a neutral point-clamped three-level inverter-fed interior permanent magnet synchronous motor drive. In the classical DTC scheme, there are significant torque and flux ripples in the drive due to low number of available switching states. To reduce the oscillations in torque and flux, a three-level inverter-operated IPMSM drive is discussed. In a three-level inverter, the increased count of active voltage vectors is results in more sinusoidal output waveforms. Moreover, stator flux plane has 12 sectors in the proposed work unlike classical DTC. Besides, the higher level of flux and torque hysteresis comparators is implemented. DC link capacitor voltage balancing scheme is also instigated to minimize voltage stress on semiconductor devices, improve stator current THD and increased capacitor life. Based on the sector information, flux and torque hysteresis output and capacitor voltage balance logic, an improved LUT is established and explained for a three-level DTC scheme. Consequently, improved stator current (THD) and decrement in torque and flux ripples are observed. To make the system robust, model reference adaptive control (MRAC) based sensorless speed estimation algorithm is realized. The proposed DTC scheme is compared with a two-level inverter-fed and a three-level-inverter-fed DTC scheme without DC link voltage balance strategy. To carry out the analysis, MATLAB/Simulink environment is utilized. Moreover, to validate the simulation results, experimental analysis of the proposed technique is carried out using dSPACE1104.

Two-Stage Model Predictive Control of Neutral-Point-Clamped Inverter-Fed Permanent-Magnet Synchronous Motor Drives Under Balanced and Unbalanced DC Links

Controlling a three-level neutral-point-clamped (3L-NPC) inverter-fed permanent-magnet synchro-nous machine (PMSM) drive is a challenging task, especially when the dc-link voltage is unbalanced. The unbalanced dc-link voltages, which are with some of the voltage vectors varying in magnitude and phase, lead to highly distorted stator current. In this article, a two-stage model predictive control (MPC) is proposed for the 3L-NPC inverter-fed PMSM drive. In the proposed MPC method, control of the 3L-NPC inverter is decoupled into two stages. In the first stage, three switching states are determined by small hexagon selection using finite control set MPC. The rest switching states are controlled using the multiple vector MPC in the second stage. In the two-stage MPC, the number of switching state evaluations can be significantly reduced, and the nonlinearity caused by the unbalanced dc links can be included in the duty cycle optimization process, leading to improved output current quality under unbalanced dc links and reduced computational burden. Moreover, the output switching frequency is fixed due to the employment of the multiple vector MPC. A thorough experimental evaluation of the proposed MPC method with the deadbeat control with the pulsewidth modulation strategy has been conducted to validate the superiority of the proposed method.

MPTC of NP‐clamped three‐level inverter‐fed permanent‐magnet synchronous motor system for NP potential imbalance suppression

For neutral point (NP)-clamped three-level inverter-fed permanent-magnet synchronous motor system, the tuning process of weighting factors in the cost function of conventional model-predictive torque control (MPTC) is complex. Also, large imbalance of NP potential can cause the deteriorated performance of flux and torque. To solve these problems, an improved MPTC is proposed. This algorithm first uses the deadbeat principle to unify the dimension of torque and flux. Then, the NP potential term in the conventional cost function can be eliminated by introducing the partition control of NP potential imbalance, which also eliminates the whole process of tuning weighting factors. After that, under the large NP potential imbalance, sectors are dynamically divided by modifying the magnitude and phase angle of medium and small vectors to improve the performance of torque and flux linkage. The experimental results show that compared with conventional MPTC, the improved MPTC can achieve fast suppression of NP potential imbalance with reducing the fluctuation of torque, flux linkage and current when NP potential imbalance is large.

Sensorless control of PMSM using an adaptively tuned SCKF

This study reports the application of an adaptively tuned square-root Cubature Kalman filter (SCKF) for the speed and position estimation of a permanent magnet synchronous motor (PMSM) drive. The proposed estimator is observed to exhibit improved noise rejection characteristics as compared to the hitherto widely applied extended Kalman filter (EKF) observer. A third degree spherical–radial cubature rule is used in the Cubature Kalman filter (CKF) to numerically compute the multivariate moment integrals of the general Bayesian estimation equation. CKF is a non-linear filter which avoids linearisation and the associated errors. The realisation of CKF using the square-root algorithm results in numerical stability, as with the realisation of EKF using the square-root algorithm. Simulation results are presented for a three-phase inverter-fed PMSM, along with the experimental results. The estimator and the control algorithms are realised on the MATLAB real-time environment, interfaced with the hardware using the National Instruments data acquisition system NI PCI-6221.

Dual-Vector Predictive Torque Control of Permanent Magnet Synchronous Motors Based on a Candidate Vector Table

In order to reduce the torque ripple of permanent magnet synchronous motors (PMSMs), this paper proposes a dual-vector predictive torque control strategy based on a candidate vector table. The main feature of this strategy is that two vectors are acted in a control period to form a vector combination, and the vector combination can be either an effective-zero combination or an effective-effective combination. In the process of establishing the vector combinations, the switching frequency is also taken into account, therefore avoiding a high switching frequency, while effectively reducing the motor torque ripple. The candidate vector table is constructed offline, and three sets of candidate vectors and their duty cycles can be determined by looking up the table. Then the cost function is used to screen the action vectors from the three sets candidate vectors, so the two vectors acted in one control period and their duty cycles can be obtained simultaneously. Finally, the feasibility and effectiveness of the proposed method are verified on a 5.2 kW two-level inverter-fed PMSM drive system.

Design and Simulation of the Control System for Inverter-fed Permanent Magnet Synchronous Motor Drive

<p>Development in the field of power electronics, cost effective DSP’s and microprocessors have opened a new era in the design and implement modern control strategies for variable speed drives.<strong> </strong>This paper presents the design of a control system which includes a non-linear controller and observer for inverter fed Permanent Magnet Synchronous Motor (PMSM) Drive. The entire design is carried out by designing of Speed Controller, Non-linear controller (NLC), State feedback controller (SFC), H<sub>∞</sub> controller as well as Non-linear full order observer (NFO). The proposed control scheme is extensively simulated under various conditions using MATLAB/Simulink, which shows better performance under all operating conditions for variable speed PMSM drive.</p>