MTPA With Pseudo‐FOC Strategy–Based BLDC for Minimization of Copper Loss and Torque Ripple

In order to improve the performance of BLDC motor system , a brushless direct current (BLDC) motor FOC control system based on LPIDBP neural network is designed in this paper, which combining LPIDBP neural network with field orientation control (FOC) strategy. The control strategy and implementation method are put forward, and the system simulation model is established. The simulation results show the control performance of designed BLDC motor FOC control system is good, the torque ripple and speed ripple is small. STM32F103B is used as the main control chip to design the BLDC motor FOC control system test platform, and a BLDC motor monitoring system is designed by VB(Visual Basic). The contrast testing speed curves from monitoring system show the best performance of BLDC motor FOC control system based on LPIDBP neural network ,the system response is the fastest, the speed ripple is the smallest, and the operation is the stablest.

This paper gives a concise review on mathematical modeling of brushless direct current (BLDC) motor, the challenges on BLDC motor, torque ripple reduction techniques, condition for minimum commutation torque ripple, and different control strategies for torque ripple reduction in sensor and sensorless BLDC motor. This review also discusses the comparison between sensor and sensorless BLDC drives, merits of sensorless BLDC drive, and outcomes of different torque ripple reduction techniques. It also gives an idea to select better control strategy for specific BLDC drive applications. The best-suited control strategies have the advantages such as high efficiency, minimum torque ripple over the entire speed range, less switching loss, simple modulation scheme, improvement in DC voltage utilization, smooth and noiseless operation, and regulation in the speed of BLDC motor. The MATLAB simulation tool is used to verify the results of few topologies.KeywordsSensor BLDCSensorless BLDCTorque rippleCuk converterLine–line flux linkage

In this article, a high-performance maximum torque per Ampere (MTPA) control strategy is proposed for surface-mounted brushless dc (BLDC) motor drive. Most of published works in the literature have not considered the effect of iron loss branch. As will be demonstrated analytically, underestimating the iron loss in the control system of BLDC motor has two undesirable effects. First, it causes torque errors. Second, the MTPA fails to track the true minimum current for a desired torque. Therefore, the control system should compensate the effect of iron loss. This compensation is proposed to achieve by a direct torque control scheme to prevent internal current loops and feedforward compensations. In addition, the Lagrange's theorem is employed to derive an MTPA criterion. It is proven that forcing the criterion to zero guarantees realization of MTPA strategy. In order to reach these control objectives, a nonlinear control method is designed with two new output, corresponding to electromagnetic torque and the MTPA criterion. Performance of the proposed controller in realization of MTPA and minimization of torque ripple is justified in real-time through simulations and experiments on a 200 W outer rotor prototype.

A novel direct torque control (DTC) method with copper loss minimization is proposed for the brushless dc motor (BLDCM) in electric vehicle (EV) application. In order to realize high efficiency and high torque control precision at the same time, a special stator flux linkage trajectory is designed based on pseudo-dq transformation for maximum torque per ampere (MTPA) control of BLDCM. The three-phase conduction voltage vectors switch table is used to realize the flux linkage tracking control for high dynamic performance of torque control. The torque ripple caused by the non-ideality of the back EMF and the commutation in traditional two-phase conduction voltage vector based DTC method can be eliminated, which improves the torque control precision. The validity and effectiveness of the proposed DTC scheme are verified through experimental results.

In Brushless DC (BLDC) motor minimized the torque ripple with the help of electronically based commutators. When torque ripple is minimizes then copper loss is also minimizes. In this paper, our main aspect to decrease the torque ripples & improved the back emf of brushless dc (BLDC) motor. This paper shows that the torque produced by the BLDC motors with trapezoidal Back EMF is constant under ideal condition. Due to freewheeling torque ripples are produced which is reduced. In this paper rotor position is determined by the Zero Crossing Detection (ZCD) of back emf. Unlike old methods of calculating Back emf of the BLDC by creating a virtual neutral point, a complimentary method is used. This method provides a wide range of speed. A pre conditioning circuit is proposed to rectify the back emf at very low speed. The rotor position can be determined even in stand still condition to minimize the torque ripple and designed to overcome the disadvantages from other torque ripple decrease methods.

Brushless dc (BLDC) motors are widely utilized in many applications. The classical maximum torque per ampere (MTPA) and maximum torque per voltage (MTPV) control strategies are commonly used with BLDC motors due to being straightforward and easy to implement. However, these classical control techniques have their own drawbacks. Specifically, the MTPA achieves high efficiency in steady-state but does not fully utilize the torque capability during transients. Meanwhile, the MTPV allows faster dynamic response but degrades the efficiency in steady-state conditions. To fully exploit the advantages of both methods, this paper proposes a new combined control scheme which utilizes MTPA and/or MTPV methods based on the operating conditions. Specifically, during steady-state operation, the MTPA is adopted due to its high efficiency, while the controller smoothly converts to the MTPV in transients to fully exploit the torque capability and achieve faster dynamic response. The proposed hybrid control method is demonstrated on an example industrial BLDC motor and is shown to achieve high efficiency in steady-state (similar to MTPA) and fast dynamic response (similar to MTPV).

Brushless direct current (BLDC) motor are high power density motors with a wide scope for use in electric vehicles, home automation, and industry. But the motor performance degrades due to improper control actions. This is caused by uncontrolled BLDC motor torque currents. Field Oriented Control (FOC) method is a solution for controlling BLDC motor, because it has the advantaged of overcoming torque ripples at low speeds. This paper presents the implementation of FOC on BLDC motor using STM32F103C8T6, which is high speed and low cost microcontroller. STM32F103C8T6 has been applied to handle FOC algorithm calculation and data processing. In order to validate the FOC algorithm system and assess the performance of the STM32F103C8T6 microcontroller, a 350-watt BLDC motor on an electric bicycle was tested and compared with a Universal controller. The tests that have been conducted proven that the FOC controller makes power more efficient, rotates BLDC motor at low speeds, and reduces torque ripple.

This paper mainly proposes a direct torque control strategy to minimize torque ripple in brushless DC (BLDC) motor. BLDC motor has large current and torque ripple when one voltage vector applied in one cycle due to its low inductance. Hence, this paper proposed a hysteresis torque control with PWM mode to control the resultant torque. Moreover, when the direct torque control system is operating during the two-phase half-bridge <TEX>$120^{\circ}$</TEX> conduction mode, large torque ripple in commutation area appears every 120 electrical degree. Based on analyzing the root of torque ripple in detail, lookup tables of switching devices states for new half-bridge modulation mode in the positive and negative reference torque put forwarded. Finally, simulations by MATLAB software and experiment results from DSP are presented to verify the feasibility and effectiveness of the proposed strategy operating in four-quadrant operation.

To obtain the constant torque of brushless DC (BLDC) motor with ideal trapezoid back EMF, rectangular phase-current is required. However, due to the tolerance in manufacturing and inevitable trade-off in motor designs, the back EMF of BLDC motor is not ideal in general, thus the torque ripple occurs if phase-current maintains rectangular waveform. To suppress the torque ripple of the BLDC motor with non-ideal back EMF, an average torque control based on one-cycle control (ATC-OCC) method is proposed in this paper, which makes the output torque equal to the reference in each cycle. To observe the average torque, an indirect energy detection method is proposed, which detects the DC bus voltage and current to calculate average torque. Comparing with the present methods, this method has the following advantages: Firstly, back EMF information is not required, thus there is no offline measurement or online estimation, adaptive to BLDC motors with different back EMF. Secondly, accurate rotor position is not required, thus there is no additional measuring device or the complicated estimation algorithm, reducing the cost of the system and the requirement for the microcontroller. Thirdly, just one single current sensor is required. Simulation results have validated the feasibility of the proposed method and its effectiveness to suppress the torque ripple.

Brushless direct current (BLDC) motors are mostly preferred for dynamic applications such as automotive industries, pumping industries, and rolling industries. It is predicted that by 2030, BLDC motors will become mainstream of power transmission in industries replacing traditional induction motors. Though the BLDC motors are gaining interest in industrial and commercial applications, the future of BLDC motors faces indispensable concerns and open research challenges. Considering the case of reliability and durability, the BLDC motor fails to yield improved fault tolerance capability, reduced electromagnetic interference, reduced acoustic noise, reduced flux ripple, and reduced torque ripple. To address these issues, closed-loop vector control is a promising methodology for BLDC motors. In the literature survey of the past five years, limited surveys were conducted on BLDC motor controllers and designing. Moreover, vital problems such as comparison between existing vector control schemes, fault tolerance control improvement, reduction in electromagnetic interference in BLDC motor controller, and other issues are not addressed. This encourages the author in conducting this survey of addressing the critical challenges of BLDC motors. Furthermore, comprehensive study on various advanced controls of BLDC motors such as fault tolerance control, Electromagnetic interference reduction, field orientation control (FOC), direct torque control (DTC), current shaping, input voltage control, intelligent control, drive-inverter topology, and its principle of operation in reducing torque ripples are discussed in detail. This paper also discusses BLDC motor history, types of BLDC motor, BLDC motor structure, Mathematical modeling of BLDC and BLDC motor standards for various applications. Key Words: Brushless direct current, industries, direct torque control.

In the field of dynamic applications, specifically within automotive, pumping, and rolling sectors, there exists a noteworthy preference for the use of Brushless Direct Current (BLDC) motors. Projections show that, by the year 2030, BLDC motors are poised to supersede classic induction motors as the dominating force in industrial power transmission. This transformation, however, is accompanied by crucial issues and unresolved research challenges in the environment of BLDC motors.The core concern revolves around the dependability and endurance of BLDC motors. These motors presently encounter obstacles in achieving advanced fault tolerance, reduced electromagnetic interference, lowered acoustic noise, as well as mitigated flux and torque fluctuations. The path of closed-loop vector control emerges as a possible technique to address these challenges.In recent literature studies spanning the previous five years, a striking scarcity of exploration in the domain of BLDC motor controllers and design becomes clear. Furthermore, key areas such as the comparative study of existing vector control schemes, the increase of fault tolerance control, the attenuation of electromagnetic interference inside BLDC motor controllers, and other pivotal elements remain undiscovered. These research lacunae serve as a motivator for the undertaking of an intensive investigation to face the fundamental issues related with BLDC motors. BLDC motors have quickly become the motor of choice for electric vehicle (EV) applications due to the fact that they are reliable, simple, and energy efficient.This detailed survey goes deep into numerous sophisticated control strategies for BLDC motors. These encompass fault tolerance control, electromagnetic interference reduction, field orientation control (FOC), direct torque control (DTC), current shaping, input voltage control, intelligent control, drive-inverter topology, and the underlying operational principles aimed at the minimization of torque irregularities. Additionally, the study goes through the historical narrative of BLDC motors, the categorization of BLDC motor kinds, their structural complexity, mathematical modeling, and the standards that govern BLDC motor uses in varied industries.

Brushless direct current (BLDC) motors are mostly preferred for dynamic applications such as automotive industries, pumping industries, and rolling industries. It is predicted that by 2030, BLDC motors will become mainstream of power transmission in industries replacing traditional induction motors. Though the BLDC motors are gaining interest in industrial and commercial applications, the future of BLDC motors faces indispensable concerns and open research challenges. Considering the case of reliability and durability, the BLDC motor fails to yield improved fault tolerance capability, reduced electromagnetic interference, reduced acoustic noise, reduced flux ripple, and reduced torque ripple. To address these issues, closed-loop vector control is a promising methodology for BLDC motors. In the literature survey of the past five years, limited surveys were conducted on BLDC motor controllers and designing. Moreover, vital problems such as comparison between existing vector control schemes, fault tolerance control improvement, reduction in electromagnetic interference in BLDC motor controller, and other issues are not addressed. This encourages the author in conducting this survey of addressing the critical challenges of BLDC motors. Furthermore, comprehensive study on various advanced controls of BLDC motors such as fault tolerance control, Electromagnetic interference reduction, field orientation control (FOC), direct torque control (DTC), current shaping, input voltage control, intelligent control, drive-inverter topology, and its principle of operation in reducing torque ripples are discussed in detail. This paper also discusses BLDC motor history, types of BLDC motor, BLDC motor structure, Mathematical modeling of BLDC and BLDC motor standards for various applications.

Hall-sensor-controlled brushless dc (BLDC) motors are widely used in many electromechanical applications due to their simplicity and good torque-speed characteristics. The conventional commutation methods include the 120° and 180° switching logics that can be derived directly from the Hall sensor signals. The 120° switching method is the most common due to its natural approximation of the maximum torque per Ampere (MTPA) operation, while the 180° switching method offers a higher available phase voltage for the same dc voltage. Both methods are typically used with additional pulse-width modulation to control the motors from a fixed dc source. Recently, attention has been given to the operation of BLDC motors with conduction angles between 120° and 180° (e.g., 150°, 160°, etc.), where some benefits may be gained. This paper proposes a new methodology that continuously extends the operation from 120° to 180°, while maintaining the MTPA property. Simulations and experimental results based on a typical industrial BLDC motor demonstrate the proposed control methodology and its benefits over the conventional alternative methods.

The torque ripple of brushless dc (BLDC) motors at low rotation speeds is prominent, while in the majority of working time of the automotive electric power steering (EPS) system, the steering rate is low and the assistant motor runs at low rotation speeds. Therefore, to develop a high-performance EPS system with a BLDC motor, the problem of torque ripple at low rotation speeds must be solved. Otherwise, the steering feel will not be smooth. This paper proposed an algorithm based on BLDC motors’ essential torque formula combined with the back-EMF (Electromotive Force) waveform coefficient to modify the target current to suppress the torque pulsation effectively. Meanwhile, the commutation process of this type motor is very short. Therefore, the torque coefficient can be regarded as constant during the commutation intervals. A direct pulse-width modulation (PWM) control method considering phase resistances is analyzed with a unipolar PWM scheme to reduce the commutation torque ripple further. Finally, simulations and experiments are conducted to verify the effectiveness of this method.

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.