Elektriajamite 4. labor (0)

Tallinn University of Technology
Department of Electrical Engineering
Report on laboratory work 4 on General Course of Electrical Drive
INDUCTION MOTOR DRIVE ( LUCAS -NÜLLE)
Jüri Lina
666BMW
Group M16 Variant 2
Tallinn 2014
1. Functional Diagram
Nameplate data:
Loading Machine
SO3636-6V
VDE 0530
IP:54
Is.KL: F
U: 390V
I: 4,4 A
4Nm/1.7kW
cos:
4050 1/min
f: 140 Hz
Induction motor:
SE2663-1K
VDE 0530
IP: 20
Is.KL: F
Δ / Y
U: 230/ 400V
I: 1,7 / 1,0A
Mot.DS
0,30 kW
cos: 0.76
1400 1/min
f: 50Hz
4. Tables of observations
Task
Operation /Record
Observation
Task 1
Find the fundamental amplitude of the block switching pattern at 25 Hz supply with boosting
55%
Task 2
Find the fundamental amplitude of the block switching pattern at 25 Hz supply without boosting
50%
Task 3 for Variant 2 (25 Hz)
Quantity
Nominal
Maximal
Impact of boosting
From Nameplate and calculation
Without
boost
With
boost
Without
boost
With
boost
M [Nm]
0.45
0.55
1.2
1.45
Nominal torque increased by ~20%. Maximum torque increased by ~20%
2,05 Nm
I [A]
0.75
0.8
2.6
2.8
Current in both cases increased by ~10%
Δ 1,7 / Y 1,0A
U [V]
84
90
86
95
Voltage in both cases increased by ~10%
Δ 230V / Y 400V
P2 [W]
35
40
60
75
Power consumption increased in both cases ~10%
300 W
η [%]
0.55
0.55
0.27
0.28
No noticable change in efficency in both cases.
76%
5. Experimental traces
Graph 1
Mechanical power and Torque as a function of speed
Graph 2
Armature current power and armature voltage as a function of speed
Graph 3
Armature current and efficency as a function of Torque
6. U/f characteristic
With boosting Without boosting
7. Solutions of the problems
4.1 How much are the nominal and maximal currents of the drive? Explain the difference of nominal and experimental current data.
From nameplate, we get that the nominal currents are Δ 1,7 / Y 1,0A. From the experiment with Δ connection , we get that the nominal current is 0.75A without boosting and 0.8A with boosting and that the maximal current is 2.6A without boosting and 2.8 with boosting.
The differences in experimental data come from using a lower frequency of 25 Hz instead of the rated frequency of 50 Hz for which the motor was designed for. Also the experimental current characteristics are affected by the characteristics of the load machine.
4.2 On the timing diagram of the block and sinusoidal patterns at 25 Hz, find the number of sectors
and the number of pulses in a sector in both cases.
Number of sectors: 6
Number of pulses:
Block pattern – 12 pulses
Sine wave – 12 pulses
4.3 How much is the maximal torque and at what speed does it occur.
According to Graph 1 maximal torque is 1.45Nm and it occurs at 430 rpm (with boosting).
4.4 Which transistors are ON in Sector 2?
Transistors 2, 5 and 3.
4.5 Call the differences between torque diagrams at different frequencies.
At lower frequencies, the amount of input power P2 required to develop the same amount of torque is smaller.