Sensorless Control Of Brushless DC Motor Research Articles

The Research controller system of Brushless DC Motor Based on DSP

Brushless DC motor (BLDCM) is a new type of motor which integrates power semiconductor and permanent magnet materials. In this paper, a sensorless brushless DC motor control system based on DSP and CPLD is proposed. The working principles of the control circuit, power inversion circuit and rotor position identification circuit with the core of TMS320F2812 and MAX7000 (EPM7032) are analyzed in detail.The test results show that the system has the characteristics of strong anti-interference, good robustness, fast starting and high efficiency.

A Sensorless and Low-Gain Brushless DC Motor Controller Using a Simplified Dynamic Force Compensator for Robot Arm Application.

Robot arms used for service applications require safe human–machine interactions; therefore, the control gain of such robot arms must be minimized to limit the force output during operation, which slows the response of the control system. To improve cost efficiency, low-resolution sensors can be used to reduce cost because the robot arms do not require high precision of position sensing. However, low-resolution sensors slow the response of closed-loop control systems, leading to low accuracy. Focusing on safety and cost reduction, this study proposed a low-gain, sensorless Brushless DC motor control architecture, which performed position and torque control using only Hall-effect sensors and a current sensor. Low-pass filters were added in servo controllers to solve the sensing problems of undersampling and noise. To improve the control system’s excessively slow response, we added a dynamic force compensator in the current controllers, simplified the system model, and conducted tuning experiments to expedite the calculation of dynamic force. These approaches achieved real-time current compensation, and accelerated control response and accuracy. Finally, a seven-axis robot arm was used in our experiments and analyses to verify the effectiveness of the simplified dynamic force compensators. Specifically, these experiments examined whether the sensorless drivers and compensators could achieve the required response and accuracy while reducing the control system’s cost.

Unbalanced ZCP Compensation Method for Position Sensorless BLDC Motor

This letter presents a position sensorless control method of brushless dc (BLDC) motors considering unbalanced zero-crossing detection of back electromotive force (back EMF). The zero-crossing point (ZCP) of back EMF voltage is detected by comparing the dc-link voltage with the back EMF voltage. The unbalanced ZCP detection is caused by the dc-link voltage drop, dc-link offset voltage, and a motor having asymmetric back EMFs. Because the sensorless BLDC motor control is based on unbalanced ZCP detection, issues with torque ripple and current ripple may be increased. Therefore, sensorless operation with unbalanced ZCP detection may be unstable. In this study, an improved sensorless control method based on a simple compensation algorithm using ZCP signals is proposed. Using the proposed control method, balanced commutation instants can be obtained and the benefits of high-performance operation of BLDC motors can be accomplished. Through application of the proposed method, the effectiveness of the proposed method was experimentally verified.

HIGH INTEGRATION BRUSHLESS DC MOTOR CONTROL SCHEME FOR NEW ENERGY VEHICLES

With the factory to power consumption, efficiency, noise, electromagnetic compatibility requirements gradually increasing, brushless dc motor will be more and more widely applied in the new energy electric cars. The paper propose the improvement of the freescale to provide a high level of integration solutions - S12ZVM mixed-signal MCU series and introduce the detail sensorless brushless dc motor control scheme implementation. Based on the freescale semiconductor MC9S12ZVML128 dedicated to auto motor control chip, combining with the FreeMASTER monitoring software user interface, build high integration brushless dc motor control experimental platform. The experimental results show the applicability and advantage of S12ZVM series control scheme on the new energy automobile motor control.

Bi-Directional Position and Speed Estimation Algorithm for Sensorless Control of BLDC Motor

Abstract The observer design for estimation of back EMF to control the Brushless DC (BLDC) motor is proposed in this paper. Rotor position of the BLDC motor is estimated using the sequence of estimated back EMF. During speed reversal of motor, the actual and estimated values of speed fail to track the reference speed and if corrective action is not taken by the observer, the motor goes into the unstable region. To overcome this problem, the speed estimation algorithm is proposed for BLDC motor control during its speed reversal operation. Infinite Impulse Response (IIR) Butterworth first order low-pass filters are used in the observer for smoothing the estimated back EMFs of the BLDC motor. A new controller scheme based on Modified Hybrid Fuzzy PI (MHFPI) controller is proposed to control the speed of the BLDC motor. The effectiveness of the proposed method has been validated through simulations for different disturbances such as step changes in the reference speed and load torque of the motor and results are compared with the existing methods.

Fuzzy with PID based Sensorless Brushless DC Motor Control

Fuzzy with PID based Sensorless Brushless DC Motor Control

New sensorless commutation method for BLDC motors based on the line‐to‐line flux linkage theory

Sensorless brushless DC (BLDC) motor control is one of today's industry's requirements. The quality of this control is strongly dependent on the exact identification of the rotor angle for switching. In this study, a new sensorless BLDC motor control is introduced that could determine the exact time of the commutation. This method is based on the line-to-line flux linkage. The unscented Kalman filter method is used to identify the parameters in the proposed method. In comparison with back electromotive force based methods, this approach has advantages such as reduction of torque ripple due to commutation operations and resistance to motor parameters’ changes. The correctness of the method and the performed comparison is proved by the computer simulation and practical results.

Sensorless Control of BLDCM Drive for a High-Speed Maglev Blower Using Low-Pass Filter

This paper develops the brushless dc motor sensorless control strategy for a high-speed maglev blower. The sensorless techniques are based on a phase voltage comparator and a nonlinear offline compensator. The nonlinear offline compensator is used to compensate for the phase delay of the back electromotive force due to a low-pass filter; the phase voltage comparator is used to compensate for variations of the phase due to changes in the load, calculation error, and unbalance of three-phase motor stator. The commutation mode based on the transition between “ $60 - \phi $ ,” “ $120 - \phi $ ,” and “ $180 - \phi $ ” by detecting the total delay angle, the process of start-up, and the antidisturbance capability is described in detail. Some experiments are implemented on a single-chip DSP controller to demonstrate the feasibility of the suggested sensorless and the good anti-interference property.

Hybrid Sliding Mode Control Technology of Electric Vehicle Based on Wireless Sensor

The purpose of this study is to solve defects of the existing control strategy long convergence time, sliding mode chattering and so on. For Sensorless Brushless DC motor control strategy, a modified extended Kalman state correction estimation scheme is proposed, and dual mode high-order non-singular terminal hybrid sliding mode control technology is put forward. TMS320F2812DSP core controller and CM200DY-12H inverter module and construction electric car core control module are established, and the program algorithm of the extended Kalman algorithm and hybrid sliding mode control is constructed. The results showed that the control system designed can suppress the system chattering, and the system has strong robustness, which has low requirement on the system model and can eliminate external disturbance input, showing outstanding performance in the convergence time and anti disturbance performance. In summary, a dual mode high-order non-singular terminal hybrid sliding mode control technology put forward is quite suitable for electric vehicle control system.

Sensorless Control of BLDC Motor Drive for an Automotive Fuel Pump Using a Hysteresis Comparator

This paper develops the brushless dc (BLDC) motor sensorless control system for an automotive fuel pump. The sensorless techniques that are based on a hysteresis comparator and a potential start-up method with a high starting torque are suggested. The hysteresis comparator is used to compensate for the phase delay of the back EMFs due to a low-pass filter (LPF) and also prevent multiple output transitions from noise or ripple in the terminal voltages. The rotor position is aligned at standstill for maximum starting torque without an additional sensor and any information of motor parameters. Also, the stator current can be easily adjusted by modulating the pulse width of the switching devices during alignment. Some experiments are implemented on a single chip DSP controller to demonstrate the feasibility of the suggested sensorless and start-up techniques.

Control System of Sensorless BLDCM Based on F28335

Brushless DC motor Sensorless control is the future development trend, Based on TI Companys DSP chip TMS320F28335 type of brushless dc motor without position sensor control system designed in this paper, Its basic structure and working principle are introduced. The position detector of the brushless DC motor use back EMF zero-crossing detection method. The test results show that the system has good dynamic and static characteristics, the reliability of the motor running.

Control System of Sensorless Brushless DC Motor Based on TMS320F240

A brushless DC(BLDC) motor with the characteristics of high speed and high power density has been more widely used in industrial area. The BLDC motor requires the position and speed sensors for control. However the position sensors are undesirable from standpoints of size, cost, maintenance and reliability. There are some different ways that can solve this problem, depending on the flux distribution. This paper describes a control system of sensorless BLDC motor. The back-EMF is adopted to detect the rotor position. The back-EMF is very small in the motor starting process, and it is difficult to obtain rotor position efficiently. A re-setting method of the rotor is proposed in the paper, and current closed loop is used for high-speed and safety in the motor starting process. A good speed and current double closed loops system is designed. The speed and current regulators are implemented by a digital signal processor(DSP). A simple algorithm is used to calculate motor speed indirectly by the software, which simplifies the system hardware structure. The hardware structure and software design of sensorless BLDC motor control system are described in details. The simulation and experimental results have shown the validity of the sensorless control system and the accuracy of the detective position signal obtained. Index Terms—sensorless, brushless DC motor, back-EMF, digital signal processor

A wide-angle wave control method of reducing torque ripple for brushless DC motor

In order to deal with torque pulsation problem caused by traditional control method for brushless DC (BLDC) motor and to achieve high precision and good stability, a novel control strategy is proposed. Compared with the traditional control scheme, by using phase voltage as a control objective and making waveform of phase current approximately quasi-sinusoidal, torque ripple of BLDC motor is reduced from the original 14% to 3.4%, while toque is increased by 3.8%. Furthermore, by detecting zero-crossings of back electromotive force (BEMF) with non-conducting phases, sensorless control is realized. The new control strategy is simple. It can minimize torque ripple, increase torque, and realize sensorless control for BLDC motor. Simulation and experiments show good performance of BLDC motor by using the new control method.

Performance comparison of PWM inverter and variable DC link inverter schemes for high-speed sensorless control of BLDC motor

A performance comparison of the pulse width modulation (PWM) inverter and variable DC link inverter schemes for a high-speed sensorless control of a brushless DC (BLDC) motor is presented. The practical implementation issues for a high-speed sensorless control are discussed and it is verified through comparative experiments that the variable DC link inverter scheme can give a more stable performance than the PWM method at high speed.

Influence of PWM modes on commutation torque ripples in sensorless brushless DC motor control system

This paper introduces four PWM modes used in the sensorless brushless DC motor control system, analyzes their different influences on the commutation torque ripple in detail, and selects the best PWM mode in four given types to reduce commutation torque ripple of Brushless OC(BLDC) motors. Simulation and experimental results show that the selection is correct and practical.