Brushless DC motor control with unknown and variable torque load

Electric Power Components and Systems, 2020

CONTENTS 1. Introduction 2. Hybrid Electric Vehicle 3. Control Scheme 4. Simulations 5. Conclusions Note References Abstract-The design of an Active Disturbance Rejection Controller for the Brushless DC motor (BLDC) that compensates load torque variations in the rotor shaft without the measurement of the rotor shaft speed is presented. The reconstruction of the unknown load and motor speed is accomplished by the combination of a generalized Proportional Integral Control (PI) and a Luenberger observer, while the stator current regulation is designed around a passivity based controller. Using parameters of a commercial motor designed for a small electric vehicle under different driving conditions, numerical simulation results are included that validate the effectiveness of the proposed scheme both in terms of transient response to changes in set points and in tracking variable speed references.

IEEE/ASME Transactions on Mechatronics, 2000

In this paper, the position-sensorless direct torque and indirect flux control of brushless dc (BLDC) motor with nonsinusoidal back electromotive force (EMF) has been extensively investigated. In the literature, several methods have been proposed for BLDC motor drives to obtain optimum current and torque control with minimum torque pulsations. Most methods are complicated and do not consider the stator flux linkage control, therefore, possible high-speed operations are not feasible. In this study, a novel and simple approach to achieve a low-frequency torque ripple-free direct torque control (DTC) with maximum efficiency based on dq reference frame is presented. The proposed sensorless method closely resembles the conventional DTC scheme used for sinusoidal ac motors such that it controls the torque directly and stator flux amplitude indirectly using d-axis current. This method does not require pulsewidth modulation and proportional plus integral regulators and also permits the regulation of varying signals. Furthermore, to eliminate the low-frequency torque oscillations, two actual and easily available line-to-line back EMF constants (k ba and k ca ) according to electrical rotor position are obtained offline and converted to the dq frame equivalents using the new line-to-line park transformation. Then, they are set up in the look-up table for torque estimation. The validity and practical applications of the proposed sensorless three-phase conduction DTC of BLDC motor drive scheme are verified through simulations and experimental results.

IEEE Transactions on Power Electronics, 2021

An enhanced linear active disturbance rejection controller (ELADRC) based rotor position sensorless field oriented control (FOC) scheme for permanent magnet synchronous motor (PMSM) drivers is proposed in this paper. The ELADRC consists of two linear extended state observers (LESOs) and a proportional current controller. One LESO is designed to estimate the back electromotive force (EMF), which is treated as the external disturbance. Then, the rotor position and speed are obtained from the estimated back EMF without any phase delay or chattering problem. The other LESO is designed to estimate the internal disturbances such as parameter and current regulation quality variations. The estimated total disturbance is used as a feedforward compensation term in the current control loop to improve the current regulation quality of the plant, which further improves the rotor position estimation performance. The plant combined with the two LESOs is equivalent to an integrator with a unity gain, which is controlled by a simple proportional current controller to generate the desired voltage vector for the pulse-width modulation (PWM) operation. Finally, the stability of the closed-loop PMSM drive system with the ELADRC-based scheme is analyzed. Based on the analysis, the parameters of the ELADRC are designed. The proposed scheme is validated by experimental results for a 275-W salient-pole PMSM drive in which the PMSM is similar to the traction motor used in Toyota Prius hybrid electric vehicles at a reduced scale.

2017 North American Power Symposium (NAPS), 2017

This paper proposes a method for direct torque control of Brushless DC (BLDC) motors. Evaluating the trapezium of back-EMF is needed, and is done via a sliding mode observer employing just one measurement of stator current. The effect of the proposed estimation algorithm is reducing the impact of switching noise and consequently eliminating the required filter. Furthermore, to overcome the uncertainties related to BLDC motors, Recursive Least Square (RLS) is regarded as a real-time estimator of inertia and viscous damping coefficients of the BLDC motor. By substituting the estimated load torque in mechanical dynamic equations, the rotor speed can be calculated. Also, to increase the robustness and decrease the rise time of the system, Modified Model Reference Adaptive System (MMRAS) is applied in order to design a new speed controller. Simulation results confirm the validity of this recommended method.

IEEE Transactions on Power Electronics, 2019

An enhanced linear active disturbance rejection controller (ELADRC) based rotor position sensorless field oriented control (FOC) scheme for permanent magnet synchronous motor (PMSM) drivers is proposed in this paper. The ELADRC consists of two linear extended state observers (LESOs) and a proportional current controller. One LESO is designed to estimate the back electromotive force (EMF), which is treated as the external disturbance. Then, the rotor position and speed are obtained from the estimated back EMF without any phase delay or chattering problem. The other LESO is designed to estimate the internal disturbances such as parameter and current regulation quality variations. The estimated total disturbance is used as a feedforward compensation term in the current control loop to improve the current regulation quality of the plant, which further improves the rotor position estimation performance. The plant combined with the two LESOs is equivalent to an integrator with a unity gain, which is controlled by a simple proportional current controller to generate the desired voltage vector for the pulse-width modulation (PWM) operation. Finally, the stability of the closed-loop PMSM drive system with the ELADRC-based scheme is analyzed. Based on the analysis, the parameters of the ELADRC are designed. The proposed scheme is validated by experimental results for a 275-W salient-pole PMSM drive in which the PMSM is similar to the traction motor used in Toyota Prius hybrid electric vehicles at a reduced scale.

The faults The Brushless direct current (BLDC) motor is very popular compared with conventional dc motor. The BLDC motor uses an electronic commutator instead of mechanical commutator hence BLDC is more reliable than the conventional dc motor. A BLDC motor has same torque-speed characteristic as a conventional dc motor but the principle of operation is more complex. BLDC motors are commonly used in high goods such as refrigerator, washing machine, dish washer, high end pump applications which require higher reliability and efficiency, due to sensor less operation in large scale production industries such as the automotive, aviation parts manufacturing and processing industries etc., In this paper focusses on the implementation of direct torque control (DTC) to control the operation of BLDC Motor drives. Here, the direct torque control of BLDC motor is derived for open looped system and closed loop system using novel DTC. The speed control through variable applied voltage in open loop system and by using proportional integral (PI) in closed loop system for permanent magnet BLDC is simulated using MATLAB software. As compared with the most recent and highly performed DTC strategy, this one proposed strategy offers improved reliability due to the balancing of switching frequency of the inverter upper and lower insulated-gate bipolar transistors, and the reduction in the average value of the motor common mode voltage (CMV), and torque ripple is reduces during sector-to-sector commutations using three-level hysteresis torque controller. And the representation of the inverter voltage space vector. Simulated results are presented and it is shown that compared with conventional current control, DTC result is reduced torque ripple and a faster dynamic response for improving drives reliability of the motor.

International Journal of Computer Applications, 2012

In this work an Exponential reaching law based Sliding mode controller (SMC) controller has been proposed for the outer loop speed control of the 3-Phase Brushless DC(BLDC) motor drive. The robust hysteresis controller is employed to control the inner loop current performance of the drive. The developed SMC control scheme is simulated on MATLAB/SIMULINK platform under varying load torque disturbances up to the rated torque capability and the variable speed performance of the drive is tested. A sliding mode based load torque observer has also been designed for implementation of the scheme on real time basis. The efficient load torque rejection capabilities of the developed control scheme using the sliding mode load torque observer is then compared with a Proportional Integral (PI) based controller.

IEEE Transactions on Industry Applications, 2005

The application of direct torque control (DTC) to brushless ac drives has been investigated extensively. This paper describes its application to brushless dc drives, and highlights the essential differences in its implementation, as regards torque estimation and the representation of the inverter voltage space vectors. Simulated and experimental results are presented, and it is shown that, compared with conventional current control, DTC results in reduced torque ripple and a faster dynamic response. Index Terms-Brushless dc (BLDC) drives, direct torque control (DTC), permanent-magnet motor.

International Journal of Mechanical Engineering and Robotics Research

This work addresses the problems inherent in the disturbances affected to the operation of electrical motor drives, a modified direct torque control which is among the excellent method of torque control of an induction motor that provide a decoupled control of flux and torque is implemented with a novel controller of active disturbance rejection controller to cancel the drawbacks of flux ripples, high torque at start-up and also variable switching frequency associated in the classical DTC. In the other side, an advanced estimator for rotor speed is used in order to rectify the problem of sensors. The proposed control strategy, implementation data, and simulations with MDTC are presented and discussed. It is concluded that MDTC-SVM proposed control topology offers high performance in steady-state operation despite the existence of the internal and external disturbances. 

This paper deals with modelling of three phases brushless dc motor with MATLAB/SIMULINK software BLDC motor have advantages according to brushless dc motor and induction motor's. They have improve speed torque charactistics, high efficiency high transient response and small size. It approaches for reducing the torque ripples of BLDC motor using DTC, by using control technique's ,but present work mainly concentrate on advanced method. The whole drive system is simulated based on the system devices, BLDC motor source inverter, space vector modulation.