All it does is ground the warning light, and ground the other two lights at the same time as a bulb test. Open circuit characteristics of a dc generator aim 1 theory. The power factor of an alternator under short circuit conditions is almost near. Voltmeter reading v sc ammeter reading i sc wattmeter reading w sc r o1 z o1 x o1 model calculations. The shortcircuit test provides information about the current capabilities of a. The synchronous machine tests give the induced voltage and the current when armature reaction is greatest, for a range of field current values. Find the generators model at the rated conditions i.
Oc and sc test of an alternator determine the total power in balanced deltaconnected load, q. The slow speed salient pole alternators are ventilated by the fan action of the. In the open circuit test for determining the synchronous impedance, the alternator is. The no load is represented by the open circuit, which is represented on the right side of the figure as the hole or incomplete part of the circuit. This method of finding the parameters of a transformer is called as an indirect loading method. The voltage should remain high with these circuits on. Open circuit test on three phase alternator electric motor power. A shortcircuit test is conducted on this alternator. Following procedure can be used for determination of regulation by mmf method. Open circuit test and short circuit test are performed on a synchronous machine to find out the synchronous impedance for large machine to determine the voltage regulation open circuit test the alternator is run at rated synchronous speed and the load terminals are kept open.
Oc and sc test of an alternator, electrical engineering. The rotor of a synchronous machine is a large electromagnet. Ee 340 spring 2011 university of nevada, las vegas. To study and measure positive, negative and zero sequence. Open circuit test and short circuit test are performed on a synchronous machine to find out the synchronous impedance for large machine. Download as docx, pdf, txt or read online from scribd. The voltage at rated frequency is applied to that lv side with the help of a variac of variable ratio auto transformer the hv side of the transformer is kept open. Open and short circuit test of transformer electrical4u. Direct loading means the transformer is to be loaded to its rated capacity for specified number of hours to. You can try checking the voltage output at the alternator to compair and verify exact alternator output. The noload or opencircuit voltage is generated in the armature windings of a synchronous machine when the armature terminals are opencircuited and the rotor is rotating at synchronous speed while the field winding is energized. Circuit diagram for separately excited dc generator for o. Hence, it is seen that the short circuit test gives copper losses of transformer and approximate equivalent resistance and reactance of the transformer. I would run the white wire back to the battery as in the oe setup.
No name of experiment page no 1 to perform the brake test on a 3 slip ring induction motor and obtain its performance characteristics 2 to start a 3phase slip ring induction motor by rotor resistance starter. Open circuit test and short circuit test are performed on a synchronous machine to find out the synchronous impedance for large machine to determine the voltage regulation. Open circuit test and short circuit test of synchronous generator. Therefore the air gap emf e r shall only be enough to provide the leakage impedance drop in the armature i. Open circuit test of synchronous machine is also called no load, saturation or magnetizing characteristics for the reason which will be clear. Test, the potential divider and motor field rheostat are brought to its minimum position. In this phasor diagram we have drawn the direction of the i a is in phase with that of the e f as per the point number 1 mentioned above. As we know that, for a synchronous machine the value of x al is of the order of 0. As described in the armature winding notes, synchronous reactance is a combination of armature winding leakage reactance and a reactance used to represent armature reaction. Load balancing and load management it has been observed in which the load on all three phases of a.
If the voltage does not change when the engine is started, if it does not get above volts, or if it charges above 15 volts then the alternator may be faulty. Open and short circuit test on transformer electrical. Open circuit test and short circuit test of synchronous. Load balancing and load management, load balancing and load management. A voltmeter, wattmeter, and an ammeter are connected in lv side of the transformer as shown. Perform tach test by entering diagnostics on the console.
Electrical engineering assignment help, alternators, oc and sc tests. Armature resistance phase of the alternator, open circuit and short circuit characteristics of the alternator. About this video i am describe in this video open circuit characteristic and short circuit characteristic. Electrical machinesii laboratory 6 ii for sc test sl no.
Open circuit and short circuit test on transformer. And determine the full load regulation of a three phase synchronous generator by synchronous impedance method 3. Synchronous machines notes part2 electric equipment. The rotor has 8 poles instead of the normal 6 and the stator has 96 slots instead of the normal 36. We conduct open circuit and short circuit test on single phase transformer to determine the efficiency and regulation of a transformer on any load condition and at any power factor. A voltmeter is optional since the applied voltage is the same as the voltmeter reading. Given below is the phasor diagram of synchronous generator. This procedure is continued until the alternator voltage is 120% of its rated voltage. The synchronous machine tests give the induced voltage and the current.
At a particular speed, a field current of is required to drive the rated armature current. The laminations are very thin and it has 12 diodes, probably scottkey diodes. Stress test the alternator place a load on the alternator by turning on the headlights, the radio and the air conditioning. Load test the battery to know if it is reliable if the battery is not fully charged. To conduct parameters and losses in a single phase transformer by open circuit and short circuit test on single phase transformer. I a 0 putting the value of e f in equation 1 we get x l v oc.
Open circuit and short circuit characteristics of synchronous. Record the values of current i, voltage v and power. Pdf open circuit and short circuit test on single phase. Phasor diagram for synchronous generator electrical4u. To predetermine the regulation by this method the following informations are to be determined.
These two points are necessary for making the phasor diagram of synchronous generator. When a dc voltage of 10 v was applied to two of the terminals, a current of 25 a was measured. These, values are referred to the hv side of the transformer. The opencircuit test, or noload test, is one of the methods used in electrical engineering to determine the noload impedance in the excitation branch of a transformer.
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