Advantages And Disadvantages Of Dc Drive System

The equivalent electrical circuit of a dc motor is shown in figure 5.2. It can be represented by a voltage source (Va) across the coil of the armature. The electrical equivalent of the armature coil can be described by an inductance (La) in series with a resistance (Ra) in series with an induced voltage (Vc) which

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.

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.

Abstract— The three-phase squirrel cage induction motor is the most widely used motor type in the industry because of its good self-starting capability, simple and rugged structure, low cost and reliability. In spite of this popularity, the induction motor has two basic limitations: (i) The standard motor is not a true constant-speed machine, its full-load slip varies from less than 1% (in high-horsepower motors) to more than 5% (in fractional-horsepower motors), and (ii) It is not inherently capable of providing variable-speed operation. The limitations of induction motor can be solved through the use of adjustable speed control method of induction machine. In this paper, various method of speed control of induction motor drive are presented.

Mankind has made many extraordinary innovations for the world most having their debut in the motor vehicle department. Inside the motor department is a race for the greatest motor to put in all cars. The motor needing both performance and economy in mind. People have disagreed often over which motor concept would be a better source to make the wheels spin. There are two motors in question; they are the hybrid and electric motor. Since they are both still fairly new, the idea of knowing which to improve and which to terminate is a difficult decision. However, this is a good time to look at both motors in their semi mass production stage. Before we invest too much money into the wrong one. We will see how the hybrid takes the lead and the

Much advancement have been made in the world electric powered cars. People think that electric cars are a new thing but they were very popular in the 1900s until there was a sudden rise in petrol engines accompanied by batteries killed electric cars by 1920. However with the recent improvements in battery technology and power electronics electric cars have made a strong comeback, in addition to that their price, practicality, and the promise of the vehicle not polluting the environment in the ways that the gas powered cars do have made them very popular among today’s youth.

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

Now a days, the switching power supply market is flourishing quickly. The trend is for DC-AC converters with low cost, higher efficiency, power saving that enable maximum features. In this project, a single-stage three-switch buck-boost inverter is designed, where stepping up, stepping down and inversion operation will takes place in single stage. This proposed inverter will overcome all the drawbacks of traditional one. Coupled inductor plays a very important role in energy transfer and eliminates the use of line frequency transformer. As the inverter having only three switches, the controlling of switches also easier than conventional one. And it has also advantages like compact design, reduced switching losses, component size, and cost.

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: 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

L. Hsiu et al. [34] at low output ripple and noise in voltage and current and for this design a model of coupled inductor and transformers on a common core is use that provide Zero-voltage– switched Dual–SEPIC converter with coupled inductor. H. F. Bilgin et al. [35] gave a design criteria, operating feature and characteristic of the buck type PWM rectifier employed in a unity PF dc motor drive. As per this paper single–stage UPF buck –type PWM uses For-low harmonic distortion in Ac supply current and nearly UPF over a wide operating shaft speed Range. And these output voltage and current in limit avoid any type of failure risk in current connection even for oldest motor design, aging in insulation, mechanical failure due to circulation

The brushless DC motors are becoming more popular in low and medium power applications due to the characteristics they have such as better speed versus torque characteristics, high dynamic response, high efficiency, noiseless operation and higher torque to weight ratio. They also have a long life span. With rapid development in power electronics, semiconductor and manufacturing technology for high performance magnetic materials, the brushless DC motors have been used for energy savings applications such as air conditioners, refrigerators, air pumps, kitchen appliances and electric vehicles.

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—This paper proposes direct torque control of induction motor simulation using conventional method and space vector pulse width modulation technique for ripple reduction. Direct Torque Control is a control technique used in AC drive systems to obtain high performance torque control and thereby controlling the speed of induction motor. The principle is based on simultaneous decoupling of stator flux and electromagnetic torque of AC drive system. DTC drives use hysteresis comparators and they suffer from high torque ripple and variable switching frequency problem. The proposed SVM based DTC reduces torque ripples. The basis of the SVM-DTC methodology is the calculation of the required voltage space vector to compensate the flux and torque errors and its generation using the SVM at each sample period. The performance of this method is demonstrated by simulation using MATLAB/Simulink software. Simulation results presented in this paper show the torque, flux linkage and stator current ripple decreases with the proposed SVM-DTC algorithm.

In the region of high voltage and power, a high quality inverter fed ac drive is more easily obtained by the use of multi-level and in the first turn of three-level - inverters. The neutral point clamped three-level inverter topology is presented in Figure.1. Several PWM methods for this inverter have