Do not touch the field rheostat control for the remainder of the experiment 0 7.
Adjust the field rheostat for a no-load current =0 A) output voltage E, of 240 V dc. Vary the field rheostat and notice of the armature voltage E. Measure the open circuit armature voltage E- Voc If not, turn off the power supply and interchange any two of the stator connection leads on the synchronous motor e. The synchronous motor should start running b. Place the resistance switches for no-load (all switches open). Make sure the brushes are in their neutral position e.
LVSIM EMS GENERATOR
Turn the DC generator field rheostat control knob full ow for minimum resistance d. Couple the synchronous motor and the DC generator with the timing belt c.
LVSIM EMS SERIES
connect the circuit shown in Figure 9-2 RMATURE SERIES FIELD RHEOSTAT ♡ free FETTO V de SHUNT b. a Using your DC Motor Generator, DC Voltmeter Ammeter and Resistive Load. Set the rheostat control knob to its proper position for normal excitation (Experiment 1. Terminals 8 and N on the power supply provide fixed DC power for the rotor winding. Terminals 1.2 and 3 on the power supply provide fixed three-phase power for the three stator windings (Three-phase power will be covered in later Experiments). 415 V 3 PHASE lo hannoo 240 V dc Figure 9.1. Using your Power Supply, AC Ammeter and Three-Phase Synchronous Motor Generator, connect the circuit shown in Figure 9-1. Because of its constant running speed, the synchronous motor will be used to mechanically drive the DC generator. PROCEDURE WARNING High voltages are present in this experiment! Do not make any connections with the power onl The power should be turned off after completing each individual measurement! 0 1. CAUTION The switch in the excitation circuit of the synchronous motor should be closed (U) only when the motor is running. The DC Compound Generator EQUIPMENT REQUIRED Refer to the Equipment Utilization Chart, in Appendix A of this manual, to obtain the list of equipment required to perform this exercise. It is the purpose of this experiment to show these major points.
This type of generator has poor regulation, but is useful in applications such as welding and arc lights where maintaining a constant output current is more important than a constant output voltage. The combined magnetic field strength remains almost unchanged and little change in output voltage will take place as the load goes from no-load to full-load If the series field is connected so that the armature current flows in such a direction as to oppose the shunt field, we obtain a differential compound generator. With the proper number of turns in the series winding, the increase in magnetic strength will compensate for the decrease caused by the shunt winding. But if the same increase in load current is made to flow through the series field winding, it will increase the strength of the magnetic field. Thus, when the load current increases the current through the shunt field winding decreases, reducing the strength of the magnetic field. (This is particularly true of internal combustion engines and induction motors) The two field windings (shunt and series) on the compound generator are connected so that their magnetic fields aid each other. c) The running speed of the driving motor may change with load. b) The armature voltage drop (fx R losses) from no-load to full-load. Their poor voltage regulation is due to three factors: a) The magnetic field strength drops as the armature voltage drops, which further reduces the magnetic field strength, which in turn reduces the armature voltage, etc. To obtain the armature voltage vs armature current load curves for both generators DISCUSSION Self-excited shunt generators have the disadvantage in that changes in their load current from no-load cause their output voltage to change also.
LVSIM EMS HOW TO
To learn how to connect both the compound and the differential compound generators.To study the properties of compound DC generators under no-load and full-load conditions.Transcribed image text: Experiment 9 The DC Compound Generator OBJECTIVE
0 kommentar(er)
