A New Sensorless Commutation Drive for Brushless DC Motors and Alternators

This paper presents the design, analysis, and implementation of a high performance and cost effective sensorless control scheme for the extensively used brushless DC motors (BLDCMs). Taking into consideration cost and ease of implementation, the commutation signals are obtained without the motor neutral voltage, multistage analog filters, A/D converter, and the complex digital phase shift (delay) circuit which are indispensable in the conventional sensorless control algorithms. Instead of detecting the zero crossing point of the non-excited phase back EMF to the neutral voltage, the commutation signals are extracted directly from the specific average terminal voltages with simple RC circuits and comparators in this study. Since the neutral voltage is not needed, the extracted commutation signal is insensitive to the common mode noise, hence the low speed performance is superior to the conventional methods. Moreover, the complex phase shift circuit has been eliminated. As a result, the control algorithm can be easily interfaced with the cost effective commercial Hall effect sensor based commutation ICs. Because of the inherent low cost property, the proposed algorithm is particularly suitable for cost sensitive products such as air purifiers, air blowers, cooling fans, and related home appliances. Theoretical analysis and experimental results show that the proposed control algorithm exhibits superior performance over a wide operation range when compared with the conventional solutions

This paper presents the analysis, design, and implementation of a high performance and cost effective sensorless control scheme for the extensively used brushless dc motors. In an effort to decrease cost and increase ease of implementation, the commutation signals are obtained without the motor neutral voltage, multistage analog filters, A/D converters, or the complex digital phase shift (delay) circuits which are indispensable in the conventional sensorless control algorithms. In the proposed method, instead of detecting the zero crossing point of the nonexcited motor back electromagnetic force (EMF) or the average motor terminal to neutral voltage, the commutation signals are extracted directly from the specific average line to line voltages with simple RC circuits and comparators. In contrast to conventional methods, the neutral voltage is not needed; therefore, the commutation signals are insensitive to the common mode noise. Moreover, the complex phase shift circuit can be eliminated. As a result, the proposed control algorithm can be easily interfaced with the cost effective commercial Hall effect sensor based commutation integrated circuits. Due to its inherent low cost, the proposed control algorithm is particularly suitable for cost sensitive products such as air purifiers, air blowers, cooling fans, and related home appliances. Theoretical analysis and experiments are conducted over a wide operating speed range and different back EMF waveforms to justify the effectiveness of the proposed method

Environmental and Economic Prospects of Low-Carbon Vehicles in Support of European Commission 2030 City Logistics Fleet Goals

Hybrid Electric Vehicles(HEVs) have seriously come into prevalence recently as car manufacturers and consumers have become more aware of the environmental and economic problems of conventional vehicles. For the alternative power-train and battery cooling systems in HEVs, an effective thermal management system is required, and many automakers are interested in using Brushless DC(BLDC) motors for cooling fans for the overall traction unit's performance and energy saving capability. This paper presents the development status of BLDC motors as major parts of the power-train, i.e. the engine cooling and battery cooling fans of HEVs. A design that uses BLDC motors for the power-train and each battery cooling fan, is successfully implemented through using electro-magnetic analysis, and prototype BLDC motors are examined. As experimental results, the BLDC motors achieved an efficiency of 85% as engine cooling fans and 72% as a battery thermal management fan motor. The electric cogging noise is significantly reduced by changing the skew of the slot pitch angle and optimizing the magnetic shape.

Motor Brushless Direct Current (BLDC) has become the preferred choice in various engineering applications. However, BLDC motor control involves high complexity, and motor performance depends on the control algorithms used. This research discusses the use of sensorless control methods, specifically the Sliding Mode Observer (SMO) for rotor position and speed estimation in BLDC motors within the context of Field-Oriented Control (FOC), validated through simulations using Matlab/Simulink. Simulation results indicate that SMO provides rapid dynamic response to current changes, albeit with slight delays at high speeds. Rotor position estimation with SMO is also reasonably accurate in both steady-state and transient conditions, affirming the iveness of SMO in sensorless control for BLDC motors. SMO can be experimentally implemented to enhance sensorless control in BLDC motors by reducing the cost of installing Hall sensors while maintaining comparable performance.

Background:Use of electric bikes (EBs) and electric scooters (ESs) has increased dramatically, and so are EB-related and ES-related orthopaedic injuries. There is limited research regarding the severity of EB injuries and whether they more closely resemble ES, motorcycle (MC), or pedal bicycle (PB) related injuries. The aim of this study was to characterize injury patterns associated with EB accidents and compare injury severity and details with those of PB, ES, and MC accidents.Methods:This was a retrospective review of trauma patients presenting to an academic, level one trauma center between 2019 and 2022 to compare EB, ES, PB, and MC trauma patients. Descriptive statistics were obtained to characterize demographic data. Two-sided Fisher exact tests were used to compare categorical data, and ANOVA was used to compare continuous variables between groups.Results:EB trauma patients were significantly more likely to experience traumatic brain injury (TBI), intracranial hemorrhage (ICH), or fractures of the head/face compared with MC (54.0% vs. 19.3%, P < 0.0001) and PB (54.0% vs. 33.5%, P = 0.0001) cohorts. EB trauma patients were more likely to lose consciousness than MC or PB trauma patients. Spine fractures (11.0%) were the most prevalent in the EB study population, followed by fractures of the acetabulum (6.0%) and clavicle/scapula/radius (5.0%). EB trauma patients were significantly more likely to be admitted to the intensive care unit (ICU) than MC trauma patients (25.0% vs. 16.0%, P = 0.0256) and were significantly more likely to present as critical trauma activations than PB trauma patients (14.0% vs. 6.0%, P = 0.0106).Conclusions:While the overall injury severity scores are similar to the modes of transport, there are differences in injury severity and patterns. EB accidents have a higher prevalence of TBIs, ICH, and facial fractures. EB trauma patients can result in high utilization of resources because many are critical trauma activations and have a higher rate of ICU stays. These data can help providers better understand injury patterns of EB accidents.

This paper presents a simple method for detection of commutation instants of the extensively used low power brushless DC motors. In the proposed method the commutation signals are obtained without any phase shift circuit which is required in the conventional sensorless control methods. So the overall cost is decreased and the sensorless control is easy to be implemented. In the proposed method, instead of detecting the zero crossing points of the unexcited motor back electromotive force, which has inherently 30° phase shift with respect to the ideal commutation point, the commutation signals are extracted directly from the motor terminal voltages differences. Simulation and experimental results are presented to justify the effectiveness of the proposed method. These results show that this method, despite of its simplicity, has acceptable stability against switching noises.

This paper focus on a novel operation of a brushless dc (BLDC) motor fed by a proportional integral (PI) controlled buck--boost converter supplemented with a battery to provide the required power to drive the BLDC motor. The operational characteristics of the proposed BLDC motor drive system for constant as well as step changes in dc link voltage of a front end converter controlled by a Xilinx System Generator (XSG) based PI controller for two quadrant operations are derived. Thus a field programmable gate array (FPGA) based PI controller manages the energy flow through the battery and the front end converter. Moreover, speed to voltage conversion logic, made to control the BLDC motor through the PI controller, improves the performance and gives optimum control under the unstable driving situation or varying load condition when the complete system becomes a subject of application to electric vehicles (EVs) and hybrid electric vehicles (HEVs). The dual closed loop control implemented for end to end speed control of the proposed drive system facilitates the system with high accuracy integrated with excellent dynamic and steady state performance. In this paper, the proposed controller was designed for a 5 kW/480 V BLDC motor drive system. The feasibility of the proposed dual loop control topology for the BLDC motor drive system is validated and verified with extensive dynamic simulation in MATLAB/SIMULINK and XSG environment.

In contrast to hybrid electric cars (HECs), the issues concerning cost, volume, and reliability are even more rigorous when developing hybrid electric scooters (HESs). Therefore, the drive topology and control strategy used in HEC cannot be applied to HES directly. This paper presents a single-stage bidirectional dc/ac converter based on a general full-bridge inverter. The converter is designed for a low-voltage brushless dc motor/alternator (BLDCM/A) used in HESs, in which the additional bulky inductor and power switches are eliminated in the proposed design. In order to increase the reliability of the commutation process, a cost-effective sensorless control scheme for the motor and alternator commutation is developed. The commutation signals are extracted directly from the average terminal voltages, in which the motor neutral voltage, multistage analog Alters, analog-to-digital converters, and the complex digital phase-shift (delay) circuits are eliminated. In addition, instead of using the complex flux- weakening control technique, the winding-changeover technique is exploited to extend the range of the operating speed. With attractive features, such as low cost and ease of implementation, the proposed approach is particularly suitable for electric bikes, electric scooters, HESs, etc. Theoretical analysis and several experiments are conducted to justify the effectiveness of the proposed method.

Sustainable development means taking care of the environment, which also means promoting green transport, which involves the systematic development of personal transport in its broadest sense. The positive aspects associated with cheap and convenient electric transport are intertwined with the problem of collisions and accidents. While developing road infrastructure for electric vehicles such as scooters, bicycles, and others, research should be conducted in parallel to ensure the highest possible level of safety for users. There is also an increase in the number of people using bicycles and electric scooters, which develop significant speeds. The problem of accidents among users of classic and electric bicycles and scooters is evident, and post-accident injuries pose a serious challenge to medical practitioners. The literature is rich in statistical analyses of accidents among users of scooters and bicycles, but there are no studies where the behaviour of users of bicycles, scooters, etc. is analysed. The authors of this study set out to develop a measurement system to assess the traffic safety of people using bicycles and scooters. The device uses LIDAR to record the speed of the vehicle and a camera, the images of which are processed by an algorithm in order to classify the user as being on a bicycle or scooter and using or not using head protection with a helmet. It is also possible to analyse the behaviour of the vehicle users under study. The article describes the built measurement device and presents the results of the initial measurements made by the device.

Brushless direct current (BLDC) motors are frequently used in dynamic applications. A Brushless DC Motor is similar to a Brushed DC Motor, except that as the names indicate, they are electronically commutated rather than using brushes for commutation. Brushes are utilized in conventional brushed direct current motors to transmit power to the rotor while they rotate in a fixed magnetic field. Small Brushless DC Motors have flourished as a result of current power electronics and microprocessor technology, both in terms of price and performance. This paper will discuss the history of BLDC motors, their different types, construction, operating principles, and several control mechanisms for driving BLDC motors in various industrial applications. Keywords: BLDC Motor, Pulse Width Modulation (PWM), Hall Effect Sensors, Sensorless control, Rotor, Stator, Back Emf, Trapezoidal Control, Sinusoidal Control, Field Oriented Control

Brushless DC (BLDC) Motor is widely used in home appliance, robot, and vehicle industry due to the merits of high power density, low noise, and simple controllability. A demands for the motor, especially slim-type BLDC motor, is expected to increase continuously since the minimizing trend of the actuators is getting attention from various applications. Because a phase inductance of the slim-type BLDC motor is large, it causes a lagging of current compared with back-electromotive force (EMF) in wide range of speed. As a result, there is a problem that reduces the motor efficiency and increases the phase current. Particularly the problem is more serious in high speed range and heavy load condition. This paper proposed control scheme for high efficiency of slim type BLDC motor which can resolve the problems as mentioned above. To synchronize the phase between the current and back-EMF of BLDC motor, it proposed lead angle control method by using current dynamics characteristic. Also, it represented the accurate calculating method of lead angle by using only the maximum value of phase current and information of DC-link voltage. For the verification of the proposed control scheme, various simulations and experiments are employed. As a result, the efficiency improvement of slim type BLDC motor is confirmed.

In many applications, brushless direct current (BLDC) motor drives use fuzzy logic controllers for speed control owing to their advantages like auto-tuning of parameters, wide operational range, low computational requirements and low cost. However, the effect of different rulesets on the transient and steady-state speed Behaviour of BLDC motors has not been widely covered in the literature. The contribution of this paper includes speed characteristics of the triangular membership function (trimf) based fuzzy proportional-integral (FPI) controller is evaluated. Rulesets of 3 × 3, 5 × 5 and 7 × 7 formed using 3, 5 and 7 trimfs are compared for their Behaviour and time required for performing computations for speed benchmark of the BLDC motor used in comprehensive electric vehicle (EV) applications. The fuzzy logic control algorithm is implemented by means of Mathworks’ Fuzzy Logic Tool-set. The results are substantiated using MATLAB/Simulink. It is thereby concluded that increasing the number of membership functions improves the dynamic and steady-state behaviour of the BLDC motor.

A sensorless control strategy of a high-speed 315 kW brushless dc (BLDC) motor based on a speed-independent flux linkage function is proposed in this paper. It addresses the two key challenges on the sensorless control of high-speed BLDC motor: proposing a speed-independent flux linkage function to ensure reliable operation in the low-speed range, and presenting correction strategy to provide accurate commutation points in the high-speed range. First, the sensorless detection circuit model of a 315 kW BLDC motor is discussed. The analysis shows that the speed-independent flux linkage function is really suitable for BLDC motor sensorless control strategy in the low-speed range. Then, an improved closed-loop system based on the change of current in the full speed range is proposed. The experimental results show that the proposed control strategy can provide a highly accurate and robust sensorless operation from near zero to 20 000 r/min.

Injuries among children resulting from the use of personal electric mobility devices are common and contribute to a range of adverse societal outcomes, including increased financial strain on healthcare systems, instances of disability, pediatric mortality, and other related consequences. Consequently, investigating the characteristics of pediatric injuries associated with this type of trauma is of paramount importance, as the findings may serve as a foundation for the development and implementation of preventive strategies. Objective. To delineate the structure of pediatric trauma and injury mechanisms associated with personal electric mobility devices across different age groups; to compare injury patterns resulting from electric scooters, hoverboards, and electric bicycles; and to examine the correlation between the use of basic protective equipment and the manifestation of trauma. Materials and Methods. The study utilized forensic medical data, including radiographic and computed tomography (CT) imaging, sourced from inpatient records at the Ivano-Frankivsk Regional Children's Clinical Hospital and forensic medical examinations conducted at the Ivano-Frankivsk Regional Bureau of Forensic Medicine. The sample comprised 50 children aged 4–18 years who sustained injuries while using personal electric mobility devices. Results. Traumatic brain injuries accounted for 72% of cases involving electric scooters, 24% for hoverboards, and 3% for electric bicycles. Neck trauma was observed in 75% of electric scooter cases, 25% for hoverboards, and none for electric bicycles. Upper limb injuries were reported in 45% of electric scooter cases, 48% for hoverboards, and 6% for electric bicycles. Lower limb injuries were documented in 56% of electric scooter cases, 37% for hoverboards, and 5% for electric bicycles. Chest trauma was most prevalent in electric bicycle cases (75%), followed by hoverboards (20%) and electric scooters (5%). The absence of basic protective equipment was found to significantly influence the frequency of injuries among children. Conclusions. The study elucidated the structure of pediatric trauma associated with the use of personal electric mobility devices. The findings demonstrated that the lack of basic protective equipment significantly impacts the incidence of injuries among children across various age groups.