The Advantages And Disadvantages Of Field Oriented Control

Starting and pull-in torque’s vary with the square of the applied voltage, and the starting current is proportional to the applied voltage, exactly as on induction motors. [7]

TM4, the industrial partner, is a leading manufacturer and supplier of traction motors and drives for electric vehicle industry in Canada. As a drive manufacturer, they always aim to provide solution which is energy efficient with small footprint. In order to achieve this, they always look for alternative software and hardware solutions. Software modifications, which may improve the system performance in comparison to their existing drive control strategy without increasing the size of the system, are always sought after for continuous improvement of their system. In this regards, the internship is relevant to them for exploring alternative control strategies.

Fig. 5.12. Control of the dc–dc converter with FLC to produce less power under voltage sag: grid voltages, related grid currents, related dc-link

Switching power converters offer an easy way to regulate both the frequency and magnitude of the voltage and current applied to a motor shown in fig(1). As a result much higher efficiency and performance can be achieved by these motor drives with less generated noises[3].

In this control method, the error voltage is integrated twice and to generate the reference signal for current tracking, this signal referred to as the nonlinear carrier signal. In the current shaping, instead of the sensed switch current for comparison, the sensed current is integrated to obtain an average value before being compared with the nonlinear carrier signal. This approach reduces the input current distortion and the noise immunity. Its physical realization is more complicated than the OCC control

Recent developments in microprocessors, magnetic materials and semiconductors technologies have offered an excellent opportunity to use ac motor in high performance

There are two primary synchronous machines, the synchronous generator and the synchronous motor. Both machines are very useful depending on the application necessary for their use. Depending on the external conditions, it is required to have an understanding of how the synchronous machine should be modeled for each use. The synchronous machine is commonly found in industrial settings, clocks, and power plants. The common factor between these fields is the requirement of running at a constant speed. The synchronous generators used in power plants are common because it is economically efficient to keep the generator running at a constant frequency. Depending on the application, the synchronous machines can be modeled proportionally between the mechanical frequency based on the number of poles and the frequency of current (see theory). Consequentially, the electrical radian frequency is determined be the electrical frequency. Modeling a synchronous machine is a simple task, provided the necessary parameters are known.

The main aim if this report is the investigation of a permanent magnet AC generator. It is required to construct the generator in COMSOL Multiphysics and understand the generator’s working. The report will also give an understanding of the working of a permanent magnet rotor that generates an induced EMF in stator winding and how it generates voltage during rotation.

Permanent magnet (PM) DC brushed and brushless motors incorporate a combination of PM and electromagnetic fields to produce torque (or force) resulting in motion. This is done in the DC motor by a PM stator and a wound armature or rotor. Current in the DC motor is automatically switched to different windings by means of a commutator and brushes to create continuous motion. In a brushless motor, the rotor incorporates the magnets, and the stator contains the windings. As the name suggests brushes are absent and hence in this case, commutation is implemented electronically with a drive amplifier that uses semiconductor switches to change current in the windings based on rotor position feedback. In this respect, the BLDC motor is equivalent to a reversed DC commutator motor, in which the magnet rotates while the conductors remain stationary. Therefore, BLDC motors often incorporate either internal or external position sensors to sense the actual rotor.

Advantages of the Brushless DC motor are their long life, better efficiency, and high RPM with no maintenance required.

Based on the modelling of SRM magnetic circuit, three models of SRM are found in literature: linear model, nonlinear model without mutual inductances, and nonlinear model with mutual inductances. Linear models in [6,7] are designed and simulated readily. On contrast nonlinear models are obtained after a large set of experimental tests to obtain the magnetic characteristics [8-15], or from a finite element method (FEM) analysis [16-18], which takes into consideration the saturation of rotor and stator materials. The nonlinear model is preferable when accurate precision is wanted. The converter used with SRM requires at least one switch per phase due to unidirectional phase current. This is a big advantage when compared to the converters for AC motor drives. Some configurations of converters used in SRM drives are presented in [19-22]. The half-bridge asymmetric converter is the most widely used for SRM drive applications, because of its high

This paper investigates adjustable speed induction motor drive using 2-level and 3-level PWM.The result obtained is verified using Matlab simulation.This result compares the hamonic contect in between 2-level and 3-level by FFT analysis tool.To analyse the resulta a carrier based pwm was taken using 2- level and 3- level topology and a threephase bridge convetor with internally generated capability SPWM/SVPWM was intrduced. Carrier freqency18*60Hz, modulation index 0.9, output voltage freqency 60 Hz and ouput voltage phase 0 degre Was fixed. So corresponing to above values,the motor speed was 1800 rpm. Or 188.5 radian/sec, hence torque is 11.87Nm. A two pole squirrel cage motor was taken subjected to 400V dc source with modulation index0.9 prduces 220v rms.when motor starts, at 0.5s it reaches its steady speed 181 radian/sec or 1728 rpm. Now by discretizing the FFT tool displays the frequency spectrum of voltage and current waveforms. These signals are stored in workspace in the ASM structure with time variable generated by the Scope block. As my model is discretized, the signal saved in this structure is sampled at a fixed step and consequently satisfies the FFT tool requirements.It was observed that value of total harmonic distortion(THD) was 65.77 percent in 2-level and 35.11 percent in 3- level for SPWM invertor and 56.77 percent for SVPWM invertor.

This thesis deals with the configuration and investigation of control framework structures for electric drives furnished with changeless magnet synchronous machines (PMSM) in car application. With the expanding prominence of multi-level inverters, the opportunity to get better of the execution of voltage source inverters has persistently been tried for different applications. The fast improvement of high exchanging recurrence power gadgets in the previous decade leads towards more extensive use of voltage source inverters in AC power era. In this way, this prompts the requirement for a regulation method with less aggregate symphonious bending, less exchanging misfortunes, and more extensive direct balance range. The present theory highlights the examination of the customary two-level inverter and the three-level diode cinched inverters for the application in car industry.

During the last decade, permanent magnet synchronous motors have been used widely in the industry to replace DC motors and induction machines. The main characteristics of these motors are the low inertia, the high efficiency, power density and reliability. Due these

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.