Essay On Speed Control

The smart distribution transformer and its controllers were evaluated through simulations using PLECS simulation platform. The system specifications used to design the simulation model are given in Table 3.

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.

As flight systems advances, new power generation is necessary which should be able to provide high-quality power generation, and solution might be Variable Frequency electrical system. The Variable frequency is generated with the power of the perfect sine wave and no harmonic distortion. This type of “Variable Frequency is generated from a generator with a 3-stage brushless with the variable speed and generates the frequency from 360 – 800Hz with an output voltage of 200V.” (Fadil. R.A., Eid. A., & Salam. M. A.,2013)

Using Field Oriented Control, current control is largely unaffected by speed of rotation of the motor[6].In the scheme of filed oriented control motor currents and voltages obtained from the motor are transformed into d-q reference frame. Measured currents from three stator phases these currents which are now in the stator reference frame are converted into two phase using Clarke transformations which are further converted into the corresponding rotor reference frame using Park transformation. The resultant current obtained is dc which is easier for the PI controllers to operate.

Many other people continued the development and improvement of electric automobiles and for a time electric automobiles were the preferred type of Automobile because of their quiet ride, quick start-up, and lack of pollution. In fact electric automobiles held the land speed record well into the early 1900’s. However, they began to decline in the early 1900’s because of the increased prevalence and efficiency of the internal combustion engine.

This chapter deals with the classification and basic operation of electric variable speed drive system and scope, merits and demerits of DC and AC drives. Then AC induction motor drive is selected for complete description. Here AC drive system is presented with its components like inverters, position sensors and current controller.

D.C Motor is used for variable speed operation because in dc motor torque and flux that can be control independently and that is achieved by armature and field current control respectively. D.C motor has many advantages delivering high starting torque, ease of control and non linear performance. But due to certain disadvantage of dc machine such as mechanical commutator and brush holder required time to time maintenance [1] .So cost of the drive system is increases. But now D.C Motor is less used in industrial applications. Because of low cost, better performance and the requirement of maintenance is less as compared to D.C Motor it make the asynchronous motor advantageous in many industrial applications. SCIM are most widely used than all the rest of the electric motor as they have all the advantages of A.C Motors and are cheaper in cost as compared to slip ring induction motor. Because of absence of slip rings, brush maintenance duration and cost associated with the wear and tear of brush are minimized. Because of these advantages, the induction motor is used in element of most of the electrical drive system for all the conditions like starting, braking, change in speed and speed reversal. To achieve the maximum efficiency of the induction motor drive, so many techniques are developed in the last few years. Now a day’s high switching frequency converters are used for changing the frequency, phase and amplitude of the input to an A.C. Motor can be changed, hence the speed and motor torque can be controlled. With the help of power electronic it is possible to

In this chapter, an overview of the state of the art system of an induction motor is carried out. It looks at various induction motor control methodologies utilizing current and voltage control to control the flux and the torque of the dynamic system. Highlight of the current and future challenges of induction motor drives are presented. To do that, a general principle of induction motor drives is discussed first follow by phase controlled of induction motor drives, frequency controlled of induction motor, and vector controlled of induction motor.

This work presents a variable speed control techniques for single phase ac motor. A pulse-width-modulation (PWM) AC chopper changes the value of the supply voltage applied to a single-phase motor. The variable supply voltage gives better speed control of motor. Harmonics generated by unit of speed control are filtered by an input filter circuit. Experimental results would be in 230V and speed control of single-phase motor shows that PWM AC Chopper is simple and cost effective control method compared to better control method to other methods in terms of simplicity and input harmonic content. In this harmonics reduction techniques for designing a Pulse Width Modulation (PWM) AC voltage controller is required. So that Total current Harmonics Distortion (THDi), obtained for to be minimized. In the Main Circuit we have used Insulated Gate Bipolar Transistor (IGBTs) or MOSFET to obtain output waveform as we shown theory of AC voltage controller with PWM techniques. We will be used at the end of project with Microcontroller are presented. We obtained results by the analysis of the AC single phase motor and PWM AC chopper is derived and its behavior of the system is studied by simulation using MATLAB and PROTEUS. The Mains power factor, motor speed, and current are analyzed for different conditions as using many circuits via op-amp, IC 555, optocoupler and ARDUINO. Harmonics analysis of the motor voltage and current are given and compared with phase control techniques.

Electrical machines have gained a distinctive interest by experts because their advantages are indisputable because of their ability to adapt to any environment and their efficient efficiency, thus exceeding other non-electric actuators. The induction machine (IM) is currently the most widely used electrical machine in both domestic and industrial applications. Its main advantage lies in its simplicity of mechanical and electrical design (absence of rotor winding (cage machine) and collector, simple structure, robust and easy to build .....). However, these advantages are accompanied by a high degree of physical complexity, linked to the electromagnetic coupling between the magnitudes of the stator and those of the rotor. This is why, for a long time, IM was only used in constant speed drives.(El-kharashi and El-dessouki, 2014).

This thesis deals with the design and analysis of control system structures for electric drives equipped with permanent magnet synchronous machines (PMSM) in automotive application.With the increasing popularity of multi-level inverters, the room for improvement of the performance of voltage source inverters has continuously been tested for various applications. The rapid development of high switching frequency power electronics in the past decade leads towards wider application of voltage source inverters in AC power generation. Therefore, this prompts the need for a modulation technique with less total harmonic distortion, fewer switching losses, and wider linear modulation range.The present thesis highlights the comparison of the conventional two-level inverter and the three-level diode clamped inverters for the application in automotive industry.

This project is aim to study the principle of pwm, single-phase inverter, three-phase inverter which leading to design a three-phase inverter(DC-AC) by using the mbed to control switch. This inverter will be intended to drive an induction motor which may need to drive. The work will involve simulation study of PWM generators, induction motors and device selected from.

Index Terms— Double fed induction generator, diode clamped multilevel matrix converters, grid, matrix Converter, space vector pulse width modulation technique, wind turbine.

Abstract: This paper investigates the dynamic performance of three phase induction motor by vector control method. The vector control algorithm is calculated on Motorola DSP56F80X. The block diagram is shown in figure which describes the structure of implement vector control algorithm. The result obtained is verified using matlab simulation. Initially speed reference is set at120 radian/s and torque taken as 0 nm. Then motor is run, speed, torque and current wave form is taken. Now speed reference changes to 160 radian/s and torque changes to 200nm and correspondence wave form is shown. I observed that it run smoothly over the full speed range, generate full torque at zero speed, and have high dynamic performance including fast acceleration and deceleration. It was originally developed for high-performance motor application for industrial drives. However, it is becoming increasingly attractive for lower performance applications as well due to FOC 's motor size, cost and power consumption reduction superiority. .. In vector control method machine is control in a synchronously rotating frame where as in sinusoidal machine variables appears as D.C. quantities. In steady state current resolved in to two control inputs I. e. direct axis and quadrature axis component

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