Experiment 1 - No Load Test of a 3-Phase Induction motor
LEARNING OUTCOMES
Control of three-phase A.C. wound-rotor induction motors.
EQUIPMENT:
A slip ring three-phase asynchronous motor (DL 1022).
1.1kW Unilab power supply (DL 1013M1).
3x 1kW resistive load (DL 1017).
3x digital multimeter (Fluke 117).
Matrix terminal.
A digital tachometer (non-contact, Extech 461700).
PROCEDURE:
- Connect the machines and equipment as shown in Figure 1.
- Record the ratings of the asynchronous machine shown at the name plate in Table 1.
- Ensure that the SAFETY key, circuit breakers and switches are activated; "START" push button switched off (inactive).
- Turn on the voltmeter and ammeters and adjust the dial of the resistor to a maximum value.
- Set the variable AC voltage control knob on the power supply to minimum (zero).
- Standby for instructor's approval to commence the experiment.
Table 1. Asynchronous motor specifications.
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| Parameter | Value |
|---|---|
| Voltage (V) | |
| Current (I) | |
| Speed (rpm) |
EXPERIMENT 1A: Measurement of no-load characteristic curves
Table 2. Measurements at different values of R
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| Rmax | R2 | R3 | R4 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Voltage (V) | Current (A) | Speed (rpm) | Voltage (V) | Current (A) | Speed (rpm) | Voltage (V) | Current (A) | Speed (rpm) | Voltage (V) | Current (A) | Speed (rpm) |
EXPERIMENT 1B: Short-circuit test
Table 3. Short-circuit test measurements at values of R0
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| V₀ (V) | I₀ (A) | I (A) | N (rpm) |
|---|---|---|---|
EXPERIMENT 1C: Open-circuit test
Table 4. Open-circuit test measurements without any values of R
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| V₀ (V) | I₀ (A) | I (A) | N (rpm) |
|---|---|---|---|
Experiment 2 - 3-Phase Alternator Operation
Table 1. Synchronous Machine specifications.
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| Parameter | Value |
|---|---|
| Voltage (V) | |
| Current (I) | |
| Speed (rpm) |
EXPERIMENT 2A & 2B: Loaded condition measurements
Table 2. Data of several parameters at different operational settings.
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| Below rated speed | At rated speed | ||||||
|---|---|---|---|---|---|---|---|
| VL (V) | IL (A) | IDC (A) | N (rpm) | VL (V) | IL (A) | IDC (A) | N (rpm) |
Experiment 3 - Flux and Armature Control Operation of a DC Motor
Table 1. DC Motor Nameplate
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| Parameter | Value | Parameter | Value |
|---|---|---|---|
| Power | Speed | ||
| Armature (V) | Armature (I) | ||
| Excitation (V) | Excitation (I) |
EXPERIMENT 3A: Flux Control Method
Table 2. Flux Control Method Data Parameters.
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| RESISTANCE (Ω) | Shunt Field Current, Ish (A) | Speed (N) |
|---|---|---|
| R7 | ||
| R6 | ||
| R5 | ||
| R4 | ||
| R3 | ||
| R2 | ||
| R1 |
EXPERIMENT 3B: Armature Control Method
Table 3. Armature Control Method Data Parameters.
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| RESISTANCE (Ω) | Armature Voltage, VRa (V) | Speed (N) |
|---|---|---|
| R7 | ||
| R6 | ||
| R5 | ||
| R4 | ||
| R3 | ||
| R2 | ||
| R1 |