Industrial drives are causes as well as victims of power quality problem. This work deals with two commonly used industrial drives- [18] Field Orientation Control (FOC) induction motor drives and Direct Torque Control (DTC) induction motor drive. These induction motor drives are customarily used in concomitant industry as loads. Being non-linear in nature, these loads are responsible for the increased total harmonic distortion levels in voltages and currents, noises which ultimately affect the power quality. The mathematical models of the FOC and DTC industrial drives have been presented in the subsequent sub-sections. 3.2 FIELD ORIENTATION CONTROL The block diagram field oriented control FOC induction motor drive is shown in Figure-3.1. It is a technique which commonly used in ac synchronous and induction motor applications. The FOC appears to be analogous to the dc machine over a wide range of speed and load conditions. It has the advantage of generating the full torque at zero speed and is capable of fast acceleration and deceleration. But the only drawback is that its performance depends critically on a very accurate coordinate transformations and flux angle estimation, which are complicated and depend on the variation of machine parameters. The concept of field oriented control was introduced by Blaschke in 1972. Since then, it has been the widely popular control method for induction motor drives. This technique has allowed independent control of the torque and flux of the dynamic machine. This could be done by direct or indirect flux orientation. In the direct field oriented control (DFOC), both the instantaneous magnitude and position of the rotor flux are supposed to be directly measured [19]. The condition for flux ... ... middle of paper ... ... The stator flux φ_s is calculated by integrating the stator voltage and torque T is calculated by the cross product of stator flux linkage vector and motor current. The error between the estimated stator flux magnitude φ_sand the reference stator flux magnitude φ_s∗is the input of a two level hysteresis comparator [19]. The alternative of the appropriate voltage vector is based on the switching table given in Table-3.1. The input quantities are the flux sector and the outputs of the two hysteresis comparators. Output of hysteresis comparator Sector 1 2 3 4 5 6 C_T=-1 V_2 V_3 V_4 V_5 V_6 V_1 C_(φ )= -1 C_T=0 V_7 V_0 V_7 V_0 V_7 V_0 C_T=+1 V_6 V_1 V_2 V_3 V_4 V_5 C_T=-1 V_3 V_4 V5 V_6 V_1 V_2 C_(φ )=+ 1 C_T=0 V_0 V_7 V_0 V_7 V_0 V_7 C_T=+1 V_5 V_6 V_1 V_2 V_3 V_4 Table-3.1 Switching Table [21] CHAPTER-4 MATLAB BASED SIMULATIONS
A maglev system is nonlinear and its open-loop response is unstable because of the nature of the magnetic forces used. PI controllers are based on a linearized model, so they do not compensate for certain variations. These variations can occur when a magnetic bearing experiences a working load change on the rotor during operation, ...
The PSS is an additional control system, which is often applied as a part of an excitation control system. The basic function of the PSS is to apply a signal to the excitation system, producing electrical torques to the rotor in phase with speed differences that damp out power oscillations. They perform within the generator’s excitation system to create a part of electrical torque, called damping torque, proportional to speed change. A CPSS can be modeled by a two stage (identical), lead-lag network which is represented by a gain K and two time constants T1 and T2. This network is connected with a washout circuit of a time constant Tw. The signal washout block acts as a high-pass filter with the time constant Tw that allows the signal associated with the oscillations in rotor speed to pass unchanged. Furthermore, it does not allow the steady state changes to modify the terminal voltages. The phase compensation blocks with time constants T1i – T4i supply the suitable phase-lead characteristics to compensate the phase lag between the input and the output signals. The commonly used structure of the PSS is shown in Fig
Anybody and everybody can become an industrial machinery mechanic; especially, those who are passionate about getting their hands plastered in motor oil, grease, and other mechanical lubricants. These people will more than likely be ecstatic about getting into industrial machinery mechanics. They need to be able to put in one hundred ten percent of their effort into becoming an industrial machinery mechanic. An industrial machinery mechanic’s overall objective on the job is to stop a mechanical error before it happens. An industrial machinery mechanics are often caught repairing, maintaining, and fabricating machinery. They will be required to have certain education and training as well as some on the job training or complete an apprenticeship program. They will receive many benefits for working in this particular field.
The ECU enters in an internal 3D table (that engineers have previously filled in with calculated values) with three variable values: spinning regime, percentage of actuated throttle pedal and engine temperature. With these parameters the ECU looks for a value in the table and extracts an estimation of the torque.
The most common style of drive train is that of the front wheel drive, abbreviated FWD. Front wheel drive was not, however, the first drive system. Front wheel drive first made its appearance in the automobile market in 1933 with the French Traction Avant, which literally means "pull from the front." At the time, the idea of having a car pulled by the front wheels was rather different, but this style of getting the power to the wheels worked rather well. What made the Traction Avant successful was that it was lighter and more fuel efficient than other car models made at the time. This increased efficiency was a result of not only eliminated weight, but also reduced power loss in moving the rotational energy to the back.
We have focused on only 10 HP oil-free reciprocating compressor, which is rotating at about 600 rpm. If unbalanced forces are rotating at such speed than obviously high vibration may occur. This compressor compresses air in two stages and both the cylinders are at the right angle. Hence, for the analysis we have primarily applied balancing of v-engines theory. By doing this we can find the mass of counter balance which is to be mounted on the crankshaft.
This involves relating the current supplied to the motor, motor shaft rotational speed, motor efficiency, and the power factor as a function of the load of the motor, similar to the figure on page 21 of the Lab Manual.
A direct current in a set of windings creates a polar magnetic field. A torque acts on the rotor due to its relation to the external magnetic field. Just as the magnetic field of the rotor becomes fully aligned with the external magnetic field, the direction of the current in the windings on the armature reverses, thereby reversing the polarity of the rotor's electromagnetic field. A torque is once again exerted on the rotor, and it continues spinning.
To understand how this motor works, we must understand the relationship between electricity, and magnetism, or simply put, electromagnetism. Direct electric current in a simple description: There are two requirements for current flow. The first is a source of electrical potential energy or EMF (electro motive force). The second is a conductor that provides a complete loop to carry the current. The reason a conductor will conduct is found at the atomic level.
Sometimes where a motor is mounted causes its output shaft to be at 90° to the machines input shaft. This requires the use of a gearbox that has an output that is 90° to its input. Gearboxes can have input shafts with output shaft...
In the field, most of the motors are induction motors. Now-a-days, industry has become more concerned about the performance of the motor. By improving the efficiency of motors we can save energy, reduce operating costs, and improve the End-User Profitability. In case of any failure, motors usually can be rewind, it is often worthy to replace a damaged motor with a new one to save energy and improve reliability.
This paper will discuss the technology of sequential gearboxes. Relatively new technology, the sequential gearbox has been applied mostly in ATV’s, motorcycles, and the automobile racing industry. Recently this technology has begun to reach passenger cars. There are three main points of discussion; the workings of a manual transmission, how a sequential gearbox works and the advantages of them, and the applications of it today. The sequential gearbox is extremely revolutionary and is only used in high-end passenger cars, but maybe one day it will be a luxury the majority of the population will be able to experience.
In Budapest at that time others around him were also seeking a solution to the DC inefficiency, and the possibility of an AC motor and the rotational effects associated with alternating currents had graced many scientists’ minds. But no one had succeeded in making a functional motor. In fact, it was thought of with the same speculation as building a perpetual motion machine; not even Tesla could hope to achieve such a feat. But, it was then in Budapest, 1882, that the elusive solution flashed through his mind. And while in Strassbourg in 1883, the first prototype of the induction motor was privately build and ran by Tesla successfully. But unable to interest anyone in Europe in promoting this radical device, Tesla accepted an offer to work for Thomas Edison in New York. Unfortunately, when Tesla described to Thomas Edison his vision for induction motors made to run smoothly and powerfully on alternating current, it was not well-accepted. The way Edison saw it, what Tesla was suggesting could potentially make a whole industry, and Edison’s own electric monopoly on power distribution, entirely obsolete. Edison still hired him to help develop DC power systems, and Tesla set about improving Edison's
Here in this review I am going to highlight the control techniques and advantages of the electric induction furnace used in steel melting.
Electrical motors function by converting electrical energy into mechanical energy by using the energy stored in the magnetic field (Sarma, 1981). The mechanical energy (torque) is produced when opposing magnetic fields try to lineup. Therefore, the center line of the north pole of a magnetic field is directly opposite to the centerline of the south pole from another magnetic field (Fitzgerald et al., 1981). The opposing magnetic fields in a motor are generated by two separate concentrically oriented components, the stator and a rotor (Figure 2-5).