A Simulation For The Motor Of A Bldc Motor Drive With The Estimation Of Initial Rotor Position

In this thesis a 3 phases, 2 poles, Y connected trapezoidal back-EMF type BLDC motor is modelled. Due to mutual inductance between stator and rotor, back-EMF has trapezoidal shape. Therefore abc phase variable model is more applicable and reliable than d-q axis. With the intention of simplifying equations and overall model the following assumptions are made.

BLDC motors are a type of synchronous motor. This means the magnetic field generated by the stator and the magnetic field generated by the rotor rotate at the same frequency. BLDC motors do not experience the “slip” that is normally seen in induction motors. BLDC motors come in single-phase, 2-phase and 3-phase configurations. Corresponding to its type, the stator has the same number of windings. Out of these, 3-phase motors are the most popular and widely used. Brushless Direct Current (BLDC) motors are one of the motor types rapidly gaining popularity. BLDC motors are used in industries such as Appliances, Automotive, Aerospace, Consumer, Medical, Industrial Automation Equipment and Instrumentation. As the name implies, BLDC motors do not use brushes for commutation; instead, they are electronically commutated.

Abstract: Nowadays an Inverter is most commonly used device in almost every field. An inverter gives ac square wave output. The objective of this paper is to obtain a three-phase ac voltage output of 3-phase inverter in Simulation. An inverter receives dc supply as input and generates an ac output. The dc input of 3-phase inverter is obtained by constant dc source. The inverter circuit consists of six IGBTs which are used for conversion of dc to ac supply. Simulation of 3-phase inverter is done in MATLAB software.

The objective of the proposed internship can be divided into the following sub-objectives – 1) develop a control strategy with variable operating switching frequency to dynamically control current ripple and reduce system losses, and 2) develop a current control strategy to improve dynamic response for the two level inverter fed PMSM drive; while taking into account the effect of different operating regions and drive design parameters. More specifically the following tasks will be accomplished for each sub-objective:

3) Sketch the distribution of magnetic flux density at t = 0.0, 0.05, 0.1, 0.15, 0.20 and 0.25

Nowadays, because of the fast evolution of electronic device, The recent developments in permanent magnet materials, solid state devices and microelectronic have led to the appearance of a new energy efficient drives using permanent magnet brushless direct current motors (PMBLDCM).

It is only after the revolution in electronics-computing and power electronics that the field of variable speed drive by AC machines has grown tremendously. Especially since digital processors, such as Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), which specialize in driving electrical machines, have facilitated experimental implantation. It is not by chance that the work on the IM is the subject of intense research in several fields, be it for the synthesis of control laws, for the calculation and optimization of yield or for the development of a strategy of diagnosis and detection of failures. This is confirmed since

Accordingly, the output signal can directly affect the ignition timing, fuel injection timing, and the precision of VVT control, thus affecting the engine’s power, fuel economy and emission cleanness. For maintenance technical staffs, mastering the sensor’s structure, working principle, and signal output characteristics will be of great importance for automobile fault diagnosis [3].

Speed sensorless control for PMSM drive has become popular in research topics in literatures [4-15]. It can be categorized into unmodel-based approach and model-based approach. The former approach, such as the High-Frequency Signal Injection (HFSI) [4-7], is suitable for low-speed running or standstill condition of PMSM. The latter approach has Back Electromotive Force (BEMF), Sliding Mode Observer (SMO) [8-9] and Extended Kalman Filter (EKF) [10-12] which are suitable for medium or high-speed running condition of PMSM. The EKF is basically a full-order stochastic observer for the recursive optimum state estimation of a nonlinear dynamic system in real time by using signals that are in noisy environment. Comparing with SMO, EKF can directly estimate the angular speed and it has high convergence rate which can give more rapid

Brushless DC (BLDC) motors are used for many low and medium power drives applications due to their high efficiency, high flux density per unit volume, low maintenance requirement, low EMI problems, high ruggedness and a range of speed control. The commutation in PMBLDCM is accomplished by solid state switches of a three phase voltage source inverter (VSI). There is a necessity of an improved power quality (PQ) as per the

This paper is organized as follows: Section II describes the three phase BLDC motor and mathematical modeling of BLDC. Section III describes the four quadrant operation of the three phase BLDC motor and its features. The controller PI and its features are explained in Section IV. In section V, the simulation results are presented. Section VI concludes the proposed work.

Power electronic converters, especially DC/AC inverters have been extending their range of use in industrial application because they provide better system efficiency, reduced energy consumption and improved quality of power. The output voltage of inverter could be fixed or variable at a fixed or variable frequency and output waveforms are therefore made up of discrete values, producing fast transition

To control commutation timing, rotor position is sensed and used for timing the switching of the output transistors to control the motor in the motor windings. The Brushless DC motor is a rotating electric motor consisting of stator armature winding and rotor permanent magnets. . They have three phase windings that are wound in star or delta connection and need a three phase inverter bridge for electric commutation. It has permanent magnet which makes it have a high ratio between torque and motor size and also suitable for applications where space and weight are critical for example, in satellite applications.

Hence the scheme proves itself superior to the DC machine. The problem faced by FOC scheme is complexity in its implementation due to dependence of machine parameters, reference frame transformation. Later DTC was introduced. Direct torque control (DTC) method is used to control the torque (finally speed) in variable frequency drives of three-phase AC electric motors. From the measured voltage and current of the motor an estimate of the motor 's magnetic flux and torque is calculated. Integrating the stator voltages, stator flux linkage is estimated. Cross product of measured motor current vector and estimated stator flux linkage vector results in estimated torque. The estimated flux magnitude and torque are then compared with their reference values. If either the estimated flux or torque deviates from the reference more than allowed limits, the transistors of the variable frequency drive are turned OFF and ON in such a way that the flux and torque errors will return in their tolerant bands as fast as possible. Thus direct torque control is one form of the hysteresis control. The method requires only the stator resistance to estimate the stator flux and torque.

Abstract— Multilevel inverter used in variable speed drive system is attracting more attention, due to various advantages that they offer when compared to standard 3-phase two level drives. For proper functioning of such systems pulse width modulation (PWM) strategy is of crucial importance. Control complexity of multilevel inverters increases rapidly with an increase in number of phases and the number of levels. The inherent low switching frequency in medium voltage industrial drive presents various challenges. Multilevel inverter topologies are increasingly being used in medium and high power applications due to their many advantages such as low power dissipation on power switches, low harmonic contents and low electromagnetic interference