Upload
svoicum
View
221
Download
0
Embed Size (px)
Citation preview
7/29/2019 2005 EPE (Gerling - Hildebrand - Hofmann - Jungnickel - Lange - Pyc)
1/5
Test-Bench for Ultra High-Speed Electrical Drives
Dieter Gerling, Rainer Hildebrand, Harald Hofmann,Kathrin Jungnickel, Benno Lange, Marcin Pyc
Institute for Electrical DrivesUniversity of Federal Defense, Munich
Werner-Heisenberg-Weg 39D-85577 Neubiberg, Germany
phone: +49 89 6004 3708, fax: +49 89 6004 3718
e-mail: [email protected]
Keywords:
Electrical Machine, High-Speed Drive, Measurement, Test Bench
Abstract
In this paper, a test-bench for electrical drives with ultra high-speeds is described. The components of this
test-bench are explained and the respective characteristics are given. The entire system shows a capability of1
max140000 minn
= ,max
30NmT = andmax
39kWP = .
1. Introduction
There is a technical trend for electrical drives towards ever increasing speeds. This holds true for industrial
drives (e.g. servo drives or industrial pumps) as well as for other applications (e.g. vacuum cleaner). The
main reason is to reduce volume and weight at constant power level (or to increase the power level at
constant volume and weight). In addition, there are many applications, which intrinsically need a very high
speed, e.g. an electrical turbo-charger for the automotive industry. For such applications a test-bench has
been designed and realized that features extremely high rotational speed.
A special challenge for ultra high-speed drives is the direct torque measurement. In [1] it is mentioned that
spindle drives may reach 180000 min-1, but the described test set-up is just capable to reach 50000 min-1. In
addition the torque is measured by an eddy current brake. This means that the test-bench intrinsically is
passive.
Acceleration measurements on a 170kW, 76000min-1
drive are described in [2]. Even with this set-up no
direct torque measurement is possible.
In [3] the authors describe the testing of a 16kW, 15000min-1
drive. The test set-up is composed of d.c. load
machine, gear box and torque transducer. With this set-up, principally motor and generator operation can be
tested. The major drawback of this test-bench is the quite low maximum speed.
A back-to-back test of a high-speed generator (110kW, 70000min-1
) is described in [4]. As the load motor is
identical to the test motor, testing the power limits is very critical. In addition, in this paper the losses are
measured calorimetrically which means a very complex set-up.
It was our aim to design and realize a test-bench for medium power (30kW and above) and ultra high-speed
(well above 100000min-1) with the possibility of direct torque (and speed) measurement in motor and
generator (i.e. 4-quadrant) operation. With such a set-up, the drawbacks of known test-benches (passivebrakes, speed below 50000min-1, back-to-back test or calorimetric measurement) can be avoided.
Test-Bench for Ultra High-Speed Electrical Drives HILDEBRAND Rainer
EPE 2005 - Dresden ISBN : 90-75815-08-5 P.1
7/29/2019 2005 EPE (Gerling - Hildebrand - Hofmann - Jungnickel - Lange - Pyc)
2/5
2. Principle design of the test-bench
The design of the test-bench is composed of a high-speed inverter-driven induction motor as a load, a gear-
set to reach an ultra high-speed and a torquemeter specially designed for this speed level. In addition, a
controlled cooling system is applied to guarantee certain operating points during the measurements. Theprinciple set-up is shown in the block diagram below (figure 1).
Fig. 1: Principle set-up of the test-bench.
3. Components of the test-bench
3.1 Load
The load of this test-bench is composed of a 4-quadrant power electronics supplying the high-speed
induction motor. The inverter is operated with a switching frequency of 16kHzsf = and a power rating of
max52kVAS = . The induction motor has a maximum speed of
1
max25000minn
= , with a field weakening
range of 2:1. The maximum torque ismax
30NmT = .
GetriebeAntrieb/Last(drive/load)
1:1/1:3/1:9
Khlmittel
Prfling(temperature)
Temperatur
(temperature)
Messwelle Temperatur
0 0 00 0 0 0 0
0 - 260 V45 - 5000 Hz
I I I
0 0 0 0
Oszilloskop(oscilloscope)
Elektronisches Wattmeter
(test object)
Drehzahl (speed)
Drehmoment (torque)
(electronic powermeter)
(gear set)
Temperatur und Durchfluss geregelt(controlled temperature and flow)
(cooling fluid)
I I I
B6
UU I
B6
UU
I
50 Hz400 V
B6
I I
Test-Bench for Ultra High-Speed Electrical Drives HILDEBRAND Rainer
EPE 2005 - Dresden ISBN : 90-75815-08-5 P.2
7/29/2019 2005 EPE (Gerling - Hildebrand - Hofmann - Jungnickel - Lange - Pyc)
3/5
The induction motor itself is supplied by a frequency inverter and control unit. As a consequence the motor
may be operated with field oriented control (FOC) or just by using a voltage-frequency-characteristic. The
closed-loop control region (torque or speed control can be selected) is limited to a maximum speed of
16000min-1. In the region between 16000min-1 and 25000min-1 just open-loop control is possible. The
reference value input may be realized by setting the system parameters (via Combivis), by analogue input
(e.g. potentiometer) , or by digital input (e.g. keyboard or bus). The bus used in our set-up is the CAN-bus.
3.2. Gear-set
The gear set, which was especially designed and built for this test-bench, offers different, selectable ratios:
1:1, 1:3, and 1:9. In addition, the maximum speed of this gear-set is limited to1
max180000 minn
= . This
limitation comes from the fact that the high-speed bearing at the output of the gear-set is not capable to reach
higher speeds. Moreover, this high-speed bearing requires an oil-pressure supply.
3.3 Torquemeter
Measuring torques at that high speed is a very delicate business. In this test-bench a measuring unit for
torque and speed has been introduced, that is capable of a maximum speed of1
max140000 minn
= . In
addition to this limitation, which limits the maximum speed of the entire test-bench, even the bearings of this
component have to be supplied by an external oil-reservoir. This oil-supply is a different one to that used for
the high-speed bearing of the gear-set. The software driver to read out the torque values has been realized
with the software package LabView.
The torque-speed-characteristics of the different parts of the entire test-bench (load motor, gear-set,
torquemeter) are shown in the following figure 2:
Fig. 2: Torque-speed-characteristics of load motor, gear-set and torquemeter.
0
5
10
15
20
25
30
35
0 25 50 75 100 125 150 175 200
Drehzahl (speed) in 1000/min
Drehmom
ent(torque)inNm Belastungsmotor (load motor)
1. Getriebestufe (1st gear)
2. Getriebestufe (2nd gear)
1. Messwelle (1st torque meter)
2. Messwelle (2nd torque meter)
P = 10 kW, 25 kW, 40 kW
0
5
10
15
20
25
30
35
0 25 50 75
0
5
10
15
20
25
30
35
0 25 50 75 100 125 150 175 200
Drehzahl (speed) in 1000/min
Drehmom
ent(torque)inNm Belastungsmotor (load motor)
1. Getriebestufe (1st gear)
2. Getriebestufe (2nd gear)
1. Messwelle (1st torque meter)
2. Messwelle (2nd torque meter)
P = 10 kW, 25 kW, 40 kW
Test-Bench for Ultra High-Speed Electrical Drives HILDEBRAND Rainer
EPE 2005 - Dresden ISBN : 90-75815-08-5 P.3
7/29/2019 2005 EPE (Gerling - Hildebrand - Hofmann - Jungnickel - Lange - Pyc)
4/5
3.4 Safety means
Testing electrical motors at ultra high-speed means that in the rotating masses an extremely high energy is
stored. Even in the case of a malfunction, the use of the test-bench must be safe for the people operating this
set-up. To guarantee this, a box has been built covering all rotating parts. This box is made of a sandwich
structure with hard and soft material. The soft material is used for energy absorbing means, the hard material
guarantees that no particles will get out of this box.
3.5 Controlled cooling
The thermal behaviour of electrical drives critically determines the performance characteristics. Therefore,
the knowledge of the thermal state of the drive is an essential prerequisite for a detailed analysis (e.g.
efficiency measurements). This test-bench is equipped with a means for controlled liquid cooling of the test
objects. The parameters are: Maximum cooling powermax
13kWP = , controlled flow up to 60 l min and
controlled temperature of the cooling liquid in the region of 10C 90C +K .
3.6 Linear amplifier
The entire test-bench is completed by a linear amplifier of maximum powermax
5.25kVAS = in the
frequency region of 45Hz 5kHzK . This linear amplifier is used to drive the test motors in addition to an
inverter supply. From a comparison the influence of the inverter supply on the test drive can be measured.Such a comparison is of special interest in the ultra high-speed region (e.g. because of possible additionaliron losses as a consequence of the inverter supply). The following figure 3 shows a photograph of therealized test-bench with the most important components (the safety means, controlled cooling, and inverterfor supplying the load motor are not shown).
Fig. 3: Photograph of the realized test-bench.
Drehstromversorgung (3 Phase-AC Power Source)5,25 kVA 45 Hz-5 kHz Sinus
Asynchron-Antrieb/Last (4 Quadranten)
(4Q-IM-drive/load)
Getriebe (gear set)
Drehmomentmess-
welle (torquemeter)
Prfling
(test object)
Drehstromversorgung (3 Phase-AC Power Source)5,25 kVA 45 Hz-5 kHz Sinus
Asynchron-Antrieb/Last (4 Quadranten)
(4Q-IM-drive/load)
Getriebe (gear set)
Drehmomentmess-
welle (torquemeter)
Prfling
(test object)
Drehstromversorgung (3 Phase-AC Power Source)5,25 kVA 45 Hz-5 kHz Sinus
Asynchron-Antrieb/Last (4 Quadranten)
(4Q-IM-drive/load)
Getriebe (gear set)
Drehmomentmess-
welle (torquemeter)
Prfling
(test object)
Drehstromversorgung (3 Phase-AC Power Source)5,25 kVA 45 Hz-5 kHz Sinus
Asynchron-Antrieb/Last (4 Quadranten)
(4Q-IM-drive/load)
Getriebe (gear set)
Drehmomentmess-
welle (torquemeter)
Prfling
(test object)
Test-Bench for Ultra High-Speed Electrical Drives HILDEBRAND Rainer
EPE 2005 - Dresden ISBN : 90-75815-08-5 P.4
7/29/2019 2005 EPE (Gerling - Hildebrand - Hofmann - Jungnickel - Lange - Pyc)
5/5
3.7 Data acquisition
A very sophisticated data acquisition system is required for such a complex test-bench. To have a singlesystem for operating the test-bench as well as for data acquisition, the software package LabView is used.Measuring devices like a Yokogawa Precision Power Meter or the Torquemeter (see section 3.3) areincluded into the set-up. The user interface realized with LabView is as simple as possible to guarantee highconcentration of the people operating the test-bench: just the values of speed, torque and power aredisplayed, together with the temperatures at some critical spots. The measured data can be stored directly toan excel-file. The user interface is shown in the following figure 4.
Fig. 4: Screenshot of the user interface realized with LabView.
4. Summary
In this paper a test-bench for electrical drives with ultra high-speeds is described, making use of direct torqueand speed measurement on the high-speed shaft. The main system is composed of inverter-suppliedinduction motor, gear-set and torquemeter. The outstanding features are: maximum speed of
1
max140000 minn
= , maximum torque ofmax
30NmT = and maximum power ofmax
39kWP = .
In addition, a high performance means for controlled liquid cooling of the test objects (13kW , 60 l min ,
10C 90C +K ) is applied to this test-bench. Moreover, dedicated safety means, a linear amplifier and a
sophisticated data acquisition system accomplish the entire measurement set-up.
References
[1] A. Boglietti, P. Ferraris, M. Lazzari, F. Profumo: Test Procedure for Very High Speed Spindle Motors, IEEEIAS Annual Meeting, 1990, vol. 1, pages 102 108
[2] A. Castagnini, I. Leone: Test Results of a Very High Speed PM Brushless Motor, International Conferenceon Electrical Machines (ICEM), 2002, Brugge, Belgium
[3] B.C. Mecrow, A.G. Jack, D.J. Atkinson, S. Green, G.J. Atkinson: Design and Testing of a 4 Phase FaultTolerant Permanent Magnet Machine for an Engine Fuel Pump, International Electric Machines and Drives
Conference (IEMDC), 2003, Madison, WI, USA[4] O. Aglen: Back-to-Back Tests of a High Speed Generator, International Electric Machines and Drives
Conference (IEMDC), 2003, Madison, WI, USA
Test-Bench for Ultra High-Speed Electrical Drives HILDEBRAND Rainer
EPE 2005 - Dresden ISBN : 90-75815-08-5 P.5