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vb. 1 to ascertain (the worth, capability, or endurance) of (a person or thing) by subjection to certain examinations; try.
What is meant by slip test?
From this test the values of Xd and Xq are determined by applying a balance reduced external voltage (say, V volts, around 25% of rated value) to the armature. The field winding remains unexcited.
Why we do slip test?
Why should you slip test? All organisations have a duty of care to their employees or customers to provide a safe environment in which to work or take leisure. Risk assessments for Slips, Trips and Falls are therefore of paramount importance. This includes taking steps to control slip and trip risks.”
On which of the motor the slip test is performed?
Answer : A no-load test is performed on a transformer to determine magnetizing current and loss. Answer : Short circuit test on transformers is conducted to determine copper losses.
What is payment slip meaning?
: a piece of paper that a person gives with a bank deposit to show how much money he or she is putting in an account.
What do you mean by synchronous speed?
: a definite speed for an alternating-current machine that is dependent on the frequency of the supply circuit because the rotating member passes one pair of poles for each alternation of the alternating current.
What does slip mean in pottery?
Slip (noun) is a liquefied suspension of clay particles in water. It differs from its very close relative, slurry, in that it is generally thinner. Slip has more clay content than its other close relative, engobe. Slip is usually the consistency of heavy cream.
What is damper winding?
: a short-circuited squirrel-cage winding placed in the pole faces and around the pole shoes of synchronous machines, the currents induced in the winding by the periodic variations in synchronous speed having the effect of a damper.
What is direct and quadrature axis?
The axis along the axis of the rotor is called the direct or the d axis. The axis perpendicular to the d axis is known as the quadrature or q axis. The direct axis flux path involves two small air gaps and is the path of the minimum reluctance.
What does XD and XQ mean?
Xd- Direct-axis Synchronous Reactance the ratio of fundamental A.C. armature Voltage to A.C. armature current produced by the direct-axis flux. Xq- Quadrature-axis Synchronous Reactance the ratio of fundamental A.C. armature Voltage to A.C. armature current produced by the quadrature-axis flux.
What is Q and D axis?
The d axis, also known as the direct axis, is the axis by which flux is produced by the field winding. The q axis, or the quadrature axis is the axis on which torque is produced.
What is SCR in generator?
Short circuit ratio or SCR is a measure of the stability of an electromechanical generator. It is the ratio of field current required to produce rated armature voltage at open circuit to the field current required to produce the rated armature current at short circuit.
What is direct axis current?
A direct axis quantity is one whose magnetic effect is along the field pole axis. Field pole axis is also known as direct axis. Based on this fact, a direct axis synchronous reactance is defined as the reactance offered to the armature flux when the peak of armature mmf is directed along the direct axis.
What does have a slip mean?
3a : a mistake in judgment, policy, or procedure. b : an unintentional and trivial mistake or fault : lapse a slip of the tongue. 4 : a leash so made that it can be quickly slipped. 5a : the act or an instance of slipping down or out of a place a slip on the ice also : a sudden mishap.
What is salient and non salient pole?
Non-Salient pole generators will have smaller diameter and longer axial length. They are used for High speed operation (typically speed will be 1500 and 3000 rpm) Better in dynamic balancing because of absence of salient poles.
What is meant by synchronous machine?
: a dynamoelectric machine (such as a generator or motor) that has a constant magnetic field and an armature which receives or delivers alternating current in synchronism with the motion of the machine and at a frequency equal to the product of the number of pairs of poles and the speed of the machine in revolutions
What is Subtransient period?
What’s its origin? First, “subtransient” refers to the fact that this quantity operates extremely fast—faster than even “transient.” In technical terms, the subtransient time period lasts from about one to three cycles, which is from 16.7 milliseconds to 50 milliseconds (assuming a power frequency of 60 Hz).
What does the power factor of an alternator depend on?
The power factor of the alternator depends upon the type of load. In case if it is an infinite bus, then the power factor of the alternator depends upon the excitation of the alternator. According to load, the alternator provides both reactive (kVAR) and real power (kW).
Why synchronous motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
What is a woman’s slip?
A slip is a woman’s undergarment worn beneath a dress or skirt. A full slip hangs from the shoulders, usually by means of narrow straps, and extends from the breast to the fashionable skirt length. A half slip (or waist slip) hangs from the waist. The word “petticoat” may also be used for half slips.
How do you calculate XD and XQ?
The method used to determine Xq and Xd, the direct and quadrature axis reactance is called slip test. Current induced in the damper winding of alternator will produce an appreciable error. Induced voltage in the open circuit field may reach dangerous values.
What are the normal values of XQ XD?
To determine the direct axis reactance (Xd) and quadrature axis reactance (Xq) of synchronous machine. Ammeter: 0 – 15A; 0 – 2.5A. Voltmeter: 0 – 40V; 0 – 250V. Wattmeter: 0 -1400 W.
What is direct axis Subtransient reactance?
The reactance during these first two or three cycle is least and the short circuit current is high. This reactance is called subtransient reactance and is denoted by X”. Since the short circuit current of the alternator lags behind the voltage by 90 degree, the reactance involved are direct axis reactance.
