Objective: To determine the equivalent circuit parameters of synchronous machine and hence to predetermine the percentage regulation at different power factors. Open Circuit Test:
The machine is run (as generator) at synchronous speed with armature terminals open. The plot of Vocl Vs If is the OCC (open circuit characteristic) which indeed is the magnetization characteristic of the machine. It exhibits the saturation effects. Short Circuit Test: The armature terminals are shorted. The machine is run at synchronous speed while If is gradually increased starting from zero value. The field current needed for ISCL = IFL (rated) is very small. The plot of ISCL Vs If is SCC (short circuit characteristic). The field current being very small this operates in linear region. So SCC is straight line, only one point on SCC corresponding to ISCL = IFL need be determined experimentally. Measurement of Armature Resistance
Using a dc source, voltmeter and ammeter take a few readings across two terminals of Stator by adjusting the series resistance Equipment Required: All the measuring instruments associated with each experiment are industrial grade. These instruments are housed in an elegant cabinet as a package. Range of instruments and accessories (standard format) 1. Three Phase 400V 3KVA 1500rpm synchronous alternator coupled with 5HP DC shunt motor 220V 1500rpm on a common base plate
2. 3/4point DC starter
3. synchronizing panel consisting of 2frequency meters, 2voltmeters, 1synchronscope, 1set of bulbs for dark and bright method, complete with ON / OFF switch and a knife switch for synchronizing
4. Suitable Digital Ammeter AC
5. Suitable Digital Wattmeter
6. Suitable Digital Voltmeter DC
7. Suitable Digital Ammeter DC
8. Suitable Loading rheostat 3?
9. Suitable Single tube rheostat
10. Suitable Double tube rheostat
11. Suitable DC Rectifier unit
12. Phase sequence indicator |
