Search

In this paper, the design of projection-based Adaptive Sliding Mode Controller (ASMC) is presented for position control of Permanent Magnet Linear Synchronous Motor (PMLSM) with unknown mover mass. The PMLSM model was first established and a vector control based on field orientation is used to decouple the cross-coupling in motor model. ASMC has been adopted to deal with the unknown mover mass and to give robust operation against external load thrust. Based on the Lyapunov method, the stability of adaptive sliding mode-controlled PMLSM has been proven and the adaptive law has been developed. Additionally, a continuous projection operator is applied to adaptive law such as to enforce the estimated mover mass within a pre-specified bound. The performance of ASMC based on continuous projection operator is investigated via simulation results within MATLAB environment. Also, a comparison study in ASMC performance is made due to the inclusion continuous and discontinuous projection operators. The simulated results showed that ASMC based on continuous projection gives better performance than that based on discontinuous one. [ABSTRACT FROM AUTHOR]

This paper proposes a sensorless control scheme for synchronous reluctance (SyR) motor drives based on the direct-flux vector control (DFVC) method. The control operates in stator-flux-oriented coordinates, using constant switching frequency. A hybrid position and speed observer is proposed, based on the combination of the active flux concept and high-frequency signal injection and demodulation. The two methods are fused together to form a unique position and speed estimate signals, with seamless transition between the two models based on reference speed. The proposed observer covers a wide speed range, from standstill operation at full load to flux weakening (FW). Furthermore, it is inherently immune from position estimation error caused by cross saturation, as proven mathematically and experimentally. The motor is operated according to the maximum torque per ampere (MTPA) law. Specific issues related to MTPA around zero torque are addressed in this paper. The proposed control technique extends the range of application of the DFVC to encoderless drives, and can be usefully adopted in those applications where both zero-speed and FW speed range operations are necessary, such as home appliances, or automotive and aerospace actuators and generators. A 2.2-kW SyR motor prototype was tested to verify the feasibility of the proposed method. Key tuning aspects are addressed in this paper. [ABSTRACT FROM PUBLISHER]

This paper presents an online maximum torque per ampere (MTPA) control strategy for interior permanent magnet synchronous motor (IPMSM) drives based on a space vector signal injection (SVSI) method. The key of the proposed method is that the high-frequency signal is injected into the space vector directly. Then, the MTPA operational point is analyzed by the variation in the stator flux linkage amplitude and stator current magnitude. Since the high-frequency signal is injected into the voltage space vector, there is no need to consider the bandwidth of the speed loop and current loop for the frequency selection of the injection signal. In addition, the SVSI method is easy to realize because the injected signal does not need to be modulated. This method can track the MTPA points accurately and it is parameters-independent. The effectiveness of the proposed method is verified by simulation and experimental results under various operation conditions. [ABSTRACT FROM AUTHOR]

Five-phase permanent magnet synchronous motors (PMSM) have special applications in which highly accurate speed and torque control of the motor are a strong requirement. Direct Torque Control (DTC) is a suitable method for the driver structure of these motors. If in this method, instead of using a common five-phase voltage source inverter, a three-phase to five-phase matrix converter is used, the low-frequency current harmonics and the high torque ripple are limited, and an improved input power factor is obtained. Because the input voltages of such converters are directly supplied by input three-phase supply voltages, an imbalance in the voltages will cause problems such as unbalanced stator currents and electromagnetic torque fluctuations. In this paper, a new method is introduced to remove speed and torque oscillator factors. For this purpose, motor torque equations were developed and the oscillation components created by the unbalanced source voltage, determined. Then, using the active and reactive power reference generator, the controller power reference was adjusted in such a way that the electromagnetic torque of the motor did not change. By this means, a number of features including speed, torque, and flux of the motor were improved in terms of the above-mentioned conditions. Simulations were analyzed using Matlab/Simulink software. [ABSTRACT FROM AUTHOR]

This paper aims to optimize real-time control for the degraded mode of a fault-tolerant power architecture but not the fault detection and isolation procedure itself. Such power architecture is dedicated to electric vehicles in which it performs the three following essential functions: traction, battery charging, and electric-grid assistance. For safety reasons, in the degraded mode, power control is limited to the traction mode. Thus, for a given torque, the proposed innovative strategy uses a novel current/voltage transform that leads to efficient real-time control of the torque. The key idea is to drive the current without a priori restrictions on its waveform, while minimizing Joule losses, i.e., the effective value of the current. It has been validated on a laboratory test bench. The studied system is based on a three-phase open-end-winding synchronous machine powered by an inverter with three full H-bridges. The last section of the paper analyzes the comparison between the classic sinusoidal current waveforms and the proposed sinusoidal current waveforms while operating on the two remaining motor phases. It results in a 14% increase of the torque produced by the permanent-magnet machine under test and a 14% decrease of the global system losses in traction mode. As a result, the new control strategy enhances traction performance in degraded mode and increases electric-vehicle autonomy in a postfailure condition. [ABSTRACT FROM PUBLISHER]

This paper proposes proportional-integral/proportional gain controller parameter tuning in a two-degrees-of-freedom (2DOF) control system using the fictitious reference iterative tuning (FRIT) method for permanent magnet synchronous motor (PMSM) speed control using a field-programmable gate array (FPGA) for a high-frequency SiC MOSFET (metal oxide semiconductor field-effect transistor) inverter. The PI-P (proportional-integral/proportional) controller parameters can be tuned using the FRIT method from one-shot experimental data without using a mathematical model of the plant. Particle swarm optimization is used for FRIT optimization. An inverter that uses a SiC MOSFET is presented to achieve high-frequency operation at up to100 kHz using a switching pulse-width modulation (PWM) technique. As a result, a high-responsivity and high-stability PMSM (permanent magnet synchronous motor) control system is achieved, where the speed response follows the ideal response characteristic for both the step response and the disturbance response. High-responsivity and optimal disturbance rejection can be achieved using the 2DOF control system. FPGA-based digital hardware control is used to maximize the switching frequency of the SiC MOSFET inverter. Finally, an experimental system is set up, and experimental results are presented to prove the viability of the proposed method. [ABSTRACT FROM AUTHOR]

To solve the startup problems of synchronous motor, we propose a technique based on overshoot startup-current and imperfect response speed controlled by traditional strategy. A self-adaptive PID algorithm based on expert feedback strategy is presented to form an application of artificial neural network to synchronous motor control. Owing to the adaptive ability to control various parameters of the start-up stage, the system can deal with errors automatically. Through self-learning of the expert system, the optimal control parameters can be selected. Simulation results show that compared to the traditional PID feedback control scheme, by applying the expert control, accuracy has been greatly improved with good system response speed. Despite a small overshoot the strategy can effectively solve the current overshoot when synchronous motor starts. Theoretical derivation and computer simulation have proved the feasibility and effectiveness of the technique. For the facilitation realization of digital control, the technology and methods adopted are practical and worthy of wider application. [ABSTRACT FROM AUTHOR]

It has been proved that chaos exists in the permanent-magnet synchronous motor (PMSM) system when its parameters satisfy some condition, and it would degrade the efficiency of the PMSM system dramatically. In this paper, an adaptive robust control method is proposed to eliminate or suppress the chaos in PMSM, based on the mathematical analysis of chaotic property of the PMSM system. It not only accounts for the parametric uncertainties (structured uncertainties) but also takes the external load torque disturbances (unstructured uncertainties) into account. Adaptive control item is designed to deal with the former while robust item is designed to deal with the latter and the parametric estimation error respectively and both of them are integrated together via a feedforward cancellation technique. Numerical simulation results show that this method is more reliable, more accurate, and thus more applicable, compared to the existing control methods. [ABSTRACT FROM AUTHOR]

The paper explains how to select the best PWM control frequency for specific Permanent Magnet Synchronous Motors (PMSM) to achieve its maximum efficiency. Examinations were carried out for a PMSM unit with the power of 1 kW, rated speed of 1000 rpm and rated torque of 6 Nm. The PWM frequency ranged from 4 kHz to 20 kHz with the increment of 1 kHz. Measurements were taken for each of the foregoing frequencies, for the load torques of 2 Nm, 4 Nm and 6 Nm and for the rotation speeds of 300 rpm, 500 rpm, 750 rpm, 1000 rpm and 1200 rpm to find out efficiency of the PMSM motor. The achieved results make it possible to properly adjust the PWM control frequency for each PMSM motor to operate the motor in the most efficient way and, in consequence, save energy consumed by that motor. [ABSTRACT FROM AUTHOR]

This article explores the speed regulation problem of permanent magnet synchronous motor (PMSM) systems subjected to unknown time-varying disturbances. A continuous sliding mode control (CSMC) technique is introduced for the speed loop to enhance the robustness of PMSM systems and eliminate the chattering phenomenon caused by high-frequency switch function in the conventional control law. However, the high control gain of the CSMC law in the presence of strong disturbances leads to large steady-state speed fluctuations for PMSM systems. In many application fields, PMSM systems are affected by time-varying disturbances instead of constant disturbances. For example, electric bicycles are usually affected by changing environmental disturbances, including wind speeds, road conditions, etc. These disturbances may be in the form of constant, ramp, and parabolic disturbances. Hence, a generalized proportional integral (GPI) observer is employed to estimate these types of disturbances. Then, the disturbance estimation method and the aforementioned CSMC method are combined to establish a composite sliding mode control method called the CSMC+GPI method for the speed loop of PMSM systems. Contrary to the conventional sliding mode control technique, the proposed method completely eliminates the chattering phenomenon caused by the switching function in the conventional control law. Moreover, a small control gain for the CSMC+GPI method is chosen by feed-forwarding estimated values to the speed controller. Hence, the steady-state speed fluctuations are small. The effectiveness of the proposed control scheme is verified by simulation and experimental result. [ABSTRACT FROM AUTHOR]

The article deals a mathematical model of an automatic control system on the basis of field oriented control method of a synchronous motor. The synchronous motor with electromagnet exitation as object control has been considered by a system of differential equations. The proposed the automatic control system consists of two closed current loop, closed torque loop and model of synchronous motor. Experimental results of the automatic control system are presented in this paper. [ABSTRACT FROM AUTHOR]

This paper deals with an innovative self-sensing control scheme based on test current instead of voltage injection. Using two-degree-of-freedom current control, one can overcome the bandwidth limitations that made test current injection unattractive during the last 20 years. The two-degree-of-freedom control scheme consists of a model-based dynamic feedforward control to set the reference response and model reference tracking controllers providing disturbance rejection and position error signals for self-sensing control. Since two-degree-of-freedom control is a model-based control scheme, the compensation for secondary saliencies is inherently included in the precontrol. It is analytically shown that, in the case of alternating test current instead of voltage injection, just the precise knowledge, in general, of the current- and position-dependent secondary diagonal element of the inductance matrix is needed in the case of inductance saliency-based self-sensing control. The effectiveness of the proposed method is proven by experimental results. [ABSTRACT FROM AUTHOR]

SUMMARY This paper proposes a new current control method for an interior permanent magnet synchronous motor (IPMSM). In the case of ac motor control, two-axis current feedback control is performed to control the voltage amplitude and phase. When the inverter voltage is saturated, current control is achieved by controlling the voltage phase. Conventional techniques require switching the mode of the control system from variable voltage mode to voltage saturation mode. However, in the conventional techniques, transient voltage saturation occurs due to switching the control system. The proposed method achieves current control in the variable voltage mode and voltage saturation mode without switching the control system. Moreover, the current response is not affected by the rotor speed. Numerical simulation results and experimental results confirm the effectiveness of the proposed current control method. [ABSTRACT FROM AUTHOR]

This paper presents the design, analysis, control, optimization and experimental evaluation of an Electrically Controlled Permanent Magnet Excited Synchronous Machine (ECPMSM) possessing field-control capability. In order to increase flux control range of the machine a three-dimensional finite element analysis (3-D FEA) and the GOT-It software optimization tool are used. The experimental results of no-load back electromotive force (back-EMF) waveform of the prototype machine and a comparison between the analysis and test results are also presented. [ABSTRACT FROM AUTHOR]

This study presents an optimized system-on-chip (SoC) based multi-axis control system for permanent magnet synchronous motor (PMSM). The multi-axis control system becomes considerably complex with increasing controlled axes and complicated control algorithms. This paper aims to provide a balanced design considering control performance, hardware constrains and feasibility. To cope with this problem, the system design is optimized by using pipeline and time division multiplexing technology. Due to the optimized architecture and the computation capability of SoC, the performance of the whole system can be preserved. To demonstrate this, a SoC implementation of the control system is presented and comprehensively analyzed. Herein, the vector control in the current loop is explained and an anti-windup proportional-integral (PI) controller is adopted in the speed loop. The sampling frequencies of the current loop and the speed loop are 16 KHz and 4 KHz respectively. Consequently, the execution time is several microseconds with reasonable consumed resources. Experimental results are shown to prove the efficiency of the proposed SoC-based solution. [ABSTRACT FROM AUTHOR]

A dual-mode synchronous rectification (SR) controller supporting both the continuous-conduction mode and discontinuous-conduction mode is developed to improve the power efficiency of a flyback converter. The dual-mode SR controller ensures nonoverlapped turning-on of the primary and secondary switches by monitoring the voltage level of the secondary switch. The dual-mode SR controller requiring four pins and only one external resistor has been implemented in a 0.35-μm BCDMOS process and applied to a 50-W flyback converter. The efficiency of the flyback converter is improved by upto 6.8% when the dual-mode SR controller is employed compared to the one employing the conventional SR controller. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of the nonlinear dynamic surface control (DSC) of chaos based on the minimum weights of RBF neural network for the permanent magnet synchronous motor system (PMSM) wherein the unknown parameters, disturbances, and chaos are presented. RBF neural network is used to approximate the nonlinearities and an adaptive law is employed to estimate unknown parameters. Then, a simple and effective controller is designed by introducing dynamic surface control technique on the basis of first-order filters. Asymptotically tracking stability in the sense of uniformly ultimate boundedness is achieved in a short time. Finally, the performance of the proposed controller is testified through simulation results. [ABSTRACT FROM AUTHOR]

This paper deals with modeling and control of three-phase permanent-magnet synchronous motors (PMSMs) under open-phase fault conditions. Suitable reference frame transformations are introduced in order to obtain a q–d axis model similar to that normally used for machines working in healthy conditions. Adoption of such a model also allows implementing vector control strategies for PMSM drives under open-phase fault conditions in a wide operating range. Simulations and experimental tests confirm the validity of the theoretical analysis. [ABSTRACT FROM AUTHOR]

Abstract: The controller of winding motor quasi-synchronous run is a new type of reactive power compensation equipment. By winding induction motor reactive power compensation principle and the principle of quasi-synchronous operation analysis, described in the main control circuit based on IGBT and DSP control system design process, and the corresponding software design. This quasi-synchronous operation controller can significantly improve the power factor, achieve energy saving [Copyright &y& Elsevier]

High-frequency signal injected methods are widely applied to the sensorless control of permanent magnet synchronous motor (PMSM) especially at standstill and low-speed range. Most of the methods are based on the tracking theory, which leads to an angle uncertain of p. The method proposed in this Letter is also based on the injection method and can calculate the rotor absolute position directly by introducing a virtual reference frame which rotates at a fixed frequency, which makes it possible to eliminate the angle uncertain of π with a simple deviation compensation method. Furthermore, all the PMSMs even with near-zero saliency can adopt the proposed method. Finally, the simulation results show that the proposed rotor position estimation method has a good performance even under load changes. [ABSTRACT FROM AUTHOR]