Analysis and Modification of a Particle Filter Algorithm for Sensorless Control of BLDC Machine

This paper investigates the performance of a newly developed particle filter (PF) algorithm for sensorless control of the Brushless DC (BLDC) machines. A number of modifications have also been incorporated to the proposed PF algorithm in order to improve its performance with respect to resampling process and robust operation when unpredicted disturbances are occurred. The disturbances investigated in this paper include the presence of unconventional Non-Gaussian noises, changes in machine’s parameters, and occurrence of inter-turn short circuit fault. In addition, the paper proposes several measures in order to improve the estimation accuracy of the filter and enhance the filter robustness against system uncertainties. In order to evaluate the performance of the PF algorithm, the sensorless control system of a 1.5 kW BLDC machine is simulated in MATLAB/Simulink environment. Simulation results show that the introduced techniques considerably improve the performance of the PF algorithm as state estimator

Critical Aspects of Electric Motor Drive Controllers and Mitigation of Torque Ripple - Review

Electric vehicles (EVs) are playing a vital role in sustainable transportation. It is estimated that by 2030, Battery EVs will become mainstream for passenger car transportation. Even though EVs are gaining interest in sustainable transportation, the future of EV power transmission is facing vital concerns and open research challenges. Considering the case of torque ripple mitigation and improved reliability control techniques in motors, many motor drive control algorithms fail to provide efficient control. To efficiently address this issue, control techniques such as Field Orientation Control (FOC), Direct Torque Control (DTC), Model Predictive Control (MPC), Sliding Mode Control (SMC), and Intelligent Control (IC) techniques are used in the motor drive control algorithms. This literature survey exclusively compares the various advanced control techniques for conventionally used EV motors such as Permanent Magnet Synchronous Motor (PMSM), Brushless Direct Current Motor (BLDC), Switched Reluctance Motor (SRM), and Induction Motors (IM). Furthermore, this paper discusses the EV-motors history, types of EVmotors, EV-motor drives powertrain mathematical modelling, and design procedure of EV-motors. The hardware results have also been compared with different control techniques for BLDC and SRM hub motors. Future direction towards the design of EV by critical selection of motors and their control techniques to minimize the torque ripple and other research opportunities to enhance the performance of EVs are also presented.publishedVersio

A solar fed BLDC motor drive for mixer grinder using a buck converter

In large and small scale applications, different kinds of variable speed driving systems can be found. For saving the energy consumption of these devices, eco-friendly electronics are used, which lead to the development of the Brushless DC motor (BLDC). Its higher power density, higher efficiency, higher torque at low speed, and low maintenance enhances the use of a BLDC motor. The existing mixer grinder consists of the universal motor, which operates in alternating current supply due to high starting torque characteristics and simple controlling of the speed. The absence of brushes and the reduction of noise in the BLDC extends its life and makes it ideal in a mixer grinder. A solar-powered BLDC motor drive for a mixer grinder is presented in this paper. A DC-DC buck converter is utilized to operate the PV (photovoltaic) array at its maximum power. The proposed hysteresis current control BLDC system has been developed in the MATLAB. The commercially available mixer grinder is presented along with the proposed simulated system for performance comparison. It can be concluded that at the no load condition, the efficiency of the experimental existing mixer grinder is 51.03% and simulated proposed system is 81.25% and at load condition, the efficiency of the experimental mixer grinder is 49.32% and simulated system is 79.85%

An optimized design modelling of PV integrated SEPIC-based four-switch inverter for sensorless PMBLDC motor control

The design of PV-based high gain SEPIC converter integrated with four-switch strategy, which has been used to achieve sensorless speed control of Permanent magnet Brushless DC motor (PMBLDC) is analysed in this work. Hence SEPIC converter coupled with Fuzzy Logic, MPPT Algorithm is employed to retain voltage. SEPIC converter is chosen as it has a continuous current operation with high gain; Fuzzy MPPT algorithm is used as it provides accurate results faster while the classical MPPT techniques provide the results with fluctuations in attaining the maximum power. Regarding the sensorless control of PMBLDC motor, the conventional six-switch strategy is replaced by four-switch strategy and the sensors are replaced by back EMF method. Four-switch strategy has the capability of reducing the losses, size, cost and complexity of control. For achieving the nominal speed, a closed-loop control is implemented with PI controller, which is tuned by GWO technique. The proposed methodology is more efficient as the motor speed remains unchanged even under the full load condition. The end result of traditional PI algorithm and PI algorithm, which have been tuned by GWO algorithm, is compared and simulated through MATLAB. This is also implemented and validated in hardware by FPGA Spartan 6E controller

Advances in Rotating Electric Machines

It is difficult to imagine a modern society without rotating electric machines. Their use has been increasing not only in the traditional fields of application but also in more contemporary fields, including renewable energy conversion systems, electric aircraft, aerospace, electric vehicles, unmanned propulsion systems, robotics, etc. This has contributed to advances in the materials, design methodologies, modeling tools, and manufacturing processes of current electric machines, which are characterized by high compactness, low weight, high power density, high torque density, and high reliability. On the other hand, the growing use of electric machines and drives in more critical applications has pushed forward the research in the area of condition monitoring and fault tolerance, leading to the development of more reliable diagnostic techniques and more fault-tolerant machines. This book presents and disseminates the most recent advances related to the theory, design, modeling, application, control, and condition monitoring of all types of rotating electric machines

Two-axis torque control of BLDC motors for electric vehicle applications.

M. Sc. Eng. University of KwaZulu-Natal, Durban 2014.This thesis begins with a literature review focusing on electric vehicle (EV) applications. Systems used for steering, braking and energy storage are investigated, with specific concentration on torque control in various DC and AC motors commonly used in EVs. A final solution for a low range personal transportation EV in the form of a wheelchair is proposed. The theme for this thesis is motion control, focusing on a two axis (or two wheel drive) brushless DC hub motor (BLDCHM) EV, with torque and direction control tracking a user reference. The operation principle for a BLDCHM is documented and the dynamic and electrical equations derived. Simulation results for motor response under different load and speed conditions are compared to practical measurements. Current and torque control loops are designed, implemented and tuned on a single-axis test-bed with an induction motor (IM) load coupled via a torque transducer. A Texas Instrument DSP development kit is used for the control algorithm bench testing. The final control algorithm is then duplicated and expanded in simulation to form a dynamic two axis system for an electric wheelchair. It incorporates both motor drive and regenerative capabilities. After demonstrating two axis controls for BLDCHMs, a control algorithm is designed simulated and compared to traditional systems. The final solution focuses specifically on an intuitive response to the driver input whilst maintaining direction tracking, even when there is a difference in smoothness of the individual terrains traversed by the left and right wheels. In addition the motor drives are equipped with controllers that ensure regenerative braking in order to recover as much energy as possible when the wheelchair is commanded to decelerate

Modelling, simulation and analysis of low-cost direct torque control of PMSM using hall-effect sensors

This thesis focuses on the development of a novel Direct Torque Control (DTC) scheme for permanent magnet (PM) synchronous motors (surface and interior types) in the constant torque region with the help of cost-effective hall-effect sensors. This method requires no DC-link sensing, which is a mandatory matter in the conventional DTC drives, therefore it reduces the cost of a conventional DTC of a permanent magnet (PM) synchronous motor and also removes common problems including; resistance change effect, low speed and integration drift. Conventional DTC drives require at least one DC-link voltage sensor (or two on the motor terminals) and two current sensors because of the necessary estimation of position, speed, torque, and stator flux in the stationary reference frame. Unlike the conventional DTC drive, the proposed method uses the rotor reference frame because the rotor position is provided by the three hall-effect sensors and does not require expensive voltage sensors. Moreover, the proposed algorithm takes the acceleration and deceleration of the motor and torque disturbances into account to improve the speed and torque responses. The basic theory of operation for the proposed topology is presented. A mathematical model for the proposed DTC of the PMSM topology is developed. A simulation program written in MATLAB/SIMULINKî is used to verify the basic operation (performance) of the proposed topology. The mathematical model is capable of simulating the steady-state, as well as dynamic response even under heavy load conditions (e.g. transient load torque at ramp up). It is believed that the proposed system offers a reliable and low-cost solution for the emerging market of DTC for PMSM drives. Finally the proposed drive, considering the constant torque region operation, is applied to the agitation part of a laundry washing machine (operating in constant torque region) for speed performance comparison with the current low-cost agitation cycle speed control technique used by washing machine companies around the world

Modular power electronics integration for improved performance in C-GEN generation systems

‘C-GEN’ machines derive the name from the rotor, which consists of steel ‘C’ core modules, which are built around a highly modular design and specifically designed for renewable energy generation. The C-GEN machine can be easily scaled in power, dismantled in parts for maintenance, and even carry on operation with defective modules. Such high degree of modularity on the machine side has yet to be matched with modular power electronics conversion and control on the electrical side. In this thesis, the modular power electronics topology is integrated in the C-GEN machine, which aims to improve the performance of the generation system in a wide range of rotational speed, especially at partial load operation. According to the mechanical structure and electrical specification of a 16kW C-GEN machine, simulation models which include the C-GEN machine model and modular power electronics model are built. On the basis of the C-GEN machine model, four modular power electronics options are proposed, and these options are mainly assessed in terms of power losses in rectifiers and fault tolerance. A novel circuit named ‘electric gear’ is proposed to adjust the modulation index of the rectifiers in the low speed region. The electric gear is able to transmit the rectifiers’ connection between parallel and series quickly, thus the DC voltage seen by the rectifier is changed, and the modulation index of the rectifier is therefore varied. Utilising the outcomes from the studies above, the modular power electronics technology is applied in a practical wave generation project. The simulation results of this project indicate that this modular power electronics topology can maintain the modulation index larger than 0.5 as long as the generator runs more than 15% of its rated speed and reduce the power loss in rectifiers by up to 70%. As a benefit brought by the improvement of the modulation index, the power quality is enhanced as well: the current THD is less than 5% in a wide rotational speed range of the generator. Finally, the functionality and operation of the modular power electronics technology and electric gear are demonstrated in the realistic system via the hardware experiment

Self-starting interior permanent magnet motor drive for electric submersible pumps

The interior permanent magnet (IPM) motor drive has evolved as the most energy efficient technology for modern motion control applications. Electric submersible pumps (ESPs) are electric motor driven fluid recovery systems. ESPs are widely used for producing oil and gas from deep downhole reservoirs. Standard ESPs are driven by classical squirrel cage induction motors (IMs) due to its self-starting capability from a balanced 3-phase ac excitation, ruggedness, simplicity, low cost and wide scale availability. Although there has been a tremendous growth in the design and development of highly efficient and reliable IPM motors for traction drive systems, application of the IPM motor technology in ESPs is still in its infancy due to challenges associated with the design and control of IPM motors. In this thesis, a new self-starting, efficient and reliable IPM motor drive technology is proposed for ESP systems to extend their efficiency, longevity and performance. This thesis investigates two different types of self-starting interior permanent magnet (IPM) motors: cage-equipped IPM motors known as line-start IPM motors and a new type of hybrid self-starting motors called hysteresis IPM motors. The limited synchronization capability of line-start IPM motors for high inertial loads is explained in this thesis. To overcome the starting and synchronization problems associated with line-start IPM motors, a new type of hybrid hysteresis IPM motor is proposed in this thesis. Equivalent circuit modeling and finite element analysis of hysteresis IPM motors are carried out in this thesis. A prototype 2.5 kW hysteresis IPM motor is constructed and experimentally tested in the laboratory. In order to limit the inrush current during starting, a stable soft starter has been designed, simulated and implemented for variable speed operations of the motor. The simulation and experimental results are presented and analyzed in this thesis. Self-starting IPM motors suffer from hunting induced torsional oscillations. Electric submersible pumps are vulnerable against sustained hunting and can experience premature failures. In this thesis, a novel stator current signature based diagnostic system for detection of torsional oscillations in IPM motor drives is proposed. The diagnostic system is non-intrusive, fast and suitable for remote condition monitoring of an ESP drive system. Finally, a position sensorless control technique is developed for an IPM motor drive operated from an offshore power supply. The proposed technique can reliably start and stabilize an IPM motor using a back-emf estimation based sensorless controller. The efficacy of the developed sensorless control technique is investigated for a prototype 3-phase, 6-pole, 480V, 10-HP submersible IPM motor drive. In summary, this thesis carried out modeling, analysis and control of different types of self-starting IPM motors to assess their viability for ESP drive systems. Different designs of self-starting IPM motors are presented in this thesis. In future, a fully scalable self-starting IPM motor drive will be designed and manufactured that can meet the industrial demands for high power, highly reliable and super-efficient ESP systems