Vega technical specification

vega
Vibration Electrical Generator for Acyclism
Technical Documentation
S Y S T E M S E N G I N E E R I N G & T E S T S R I G S

of 8
Pôle d’activités Yvon MORANDAT - 1480 avenue d’Arménie - 13120 Gardanne - FRANCE
tel. : +33(0)4 42 24 52 00 contact@nerys.biz www.nerys.biz
The torsional vibrations generated by internal combustion engines  ACYCLISM
The operation of alternative internal combustion
engines involves alternance between compression
and combustion steps.
This means an alternance between positive torque
steps (the engine produces a mechanical work,
provided by the combustion) and negative torque
steps (the engine consumes a mechanical work, used
for the compression).
The engine torque used to run the vehicle is the
average value of these positive and negative
torques.
This alternance of torque involves an acyclism. The consequence is a non-uniform rotational
speed that is composed of two components:
 An average and uniform speed component
 A pulsed component
THE ISSUE OF ACYCLISM
Although filtered by the flywheel, the acyclism propagates to the kinematic chain (clutch,
gearbox, transmission), as well as the engine accessories (alternator, AC compressor, vaccum
pump, belts, etc.). This generates harmful vibro-acoustic phenomena both for the comfort of
the user and for the equipment subject to it (accelerated aging, loss of performance or
functional characteristics).
Today, due to increased performances and efficiency, optimized equipment and the growing
concern for reliability, manufacturers integrate increasingly consideration of the acyclism in
the technical requests both for the design of equipment and for carrying out the tests.
Including acyclisme in their tests enables manufacturers to:
 Caracterize the equipment performances
 Check the equipment reliability and qualify the lifetime with endurance tests
Uniform mean speed Pulsed speed
Acyclic speed

of 8
HOW THE ACYCLISM IS GENERATED?
To simulate the engine acyclism on a test bench, tree methods can be applied:
METHOD Strengths Weak points
The mechanical generation of
acyclism: using a drive shaft
keyed so that the angle of the
cardan break generates a
sinusoidal speed on harmonic 2
between the two ends of the
shaft.
 Low cost  Only the harmonic 2
is generated
 Limited speed
 Encombrement
 The phase is
constant but not
tunable
The hydraulic generation of
acyclism: an hydraulic rotating
actuator is used to add an angular
oscillation to a constant speed
provided by an electrical engine.
 High level dynamic
torque
 Multi-harmonic
generation
possible
 Tunable phase
 High cost
 Technical
complexity
 Limitation due to
the hydraulic
passband
The electrical generation of
acyclism: An electric engine is
used. The generation of acyclism
is obtained by analog setpoint
signal applied to the inverter.
 Technical
simplicity
 Low cost
 Easy to use
 Multi-harmonic
generation
possible
 Tunable phase
 Level of acyclism
limited by the ratio
torque/inertia of the
engine

of 8
NERYS STANDARD SOLUTION:
VEGA, the Acyclism generator designed by NERYS, is intended for generate, measure and manage the
acyclism on an electrical engine. This allows to simulate, by the use of an electrical engine, the torsional
vibration naturally produced by combustion engines.
This is an easy and cost-efficiency way to simulate the acyclic environment of a real engine, and so to
test, validate and characterize the behaviour of equipments used on engines, as alternators, pumps,
transmission devices, etc.
SYSTEM LAYOUT
Fig. 1 General layout

of 8
Includes the following parts:
An electric cabinet, with :
 The protection and
switching devices
 The inverter
 The electric devices for the control
and safety
A control cabinet, with :
 A computer (PC)
 A data acquisition system
 A front panel with
buttons and light
indicators
A synchron brushless servomotor
An incremental encoder used for the acyclism process control
A dedicated software managing the acyclism generator

of 8
DETAILLED SPECIFICATIONS
Unit Version A Version B
Electrical engine :
Technology Synchrone brushless motor
Nominal power kW 41 60
Nominal torque Nm 132 226
Max speed * rpm 3500 4000
Rotor inertia Kg.m² 0.013 0.039
Cooling Forced air convection
Electric cabinet :
Power supply 400V 3-ph. - 48kVA 400V 3 ph. - 75kVA
Dimensions (L x P x H) mm 800 x 400 x 1900 ** 800 x 400 x 1900 **
Control cabinet :
Power supply 230V – 1kVA 230V – 1kVA
Dimensions (L x P x H) mm 600 x 600 x 900 600 x 600 x 900
Acquisition system Embedded Real-time controller
(National Instruments)
Features
Acyclism servo-control Level and phase
Generated acyclism order Fractionnary, from 1 to 5
Incremental encoder Imp/tr 640
Multi-order generation Optional, each order servo-controlled on
level and phase
Performances ***
Exemple 1
Total inertia (tested equipment + interfaces) Kg.m² 0.015 0.05
Generated order 2 2
Rotational speed rpm 1000 1000
Max possible acyclism level % 21.5 11.6
Exemple 2
Generated order 4 4
Exemple 3
Generated order 1.5 1.5

of 8
* Higher speeds are possible but request special bearings, deflux mode in the inverter, and liquid-
cooling for the motor and the inverter. These configurations can be proposed as specific
applications.
** +410 mm high with the brake resistance
*** The performances of the VEGA acyclism generator depend mainly on the inertia value of the
tested equipment and interfaces. The values mentioned in the above table are, in case of direct
driving of the tested device.
SOFTWARE FEATURES:
VEGA product includes the VASCO Acyclism software, that is the VASCO Suite software
package plus the Acyclism plugin with specific features for the control of acyclisme.
More detailed information on the standard VASCO Suite software package is available on the
following link: http://www.nerys.biz/index.php/lien-vers-vasco-suite.html.
VASCO Acyclism software can be implemented in two different situations:
Vasco Acyclism is used as a supervisor
The VEGA package is a subset of a global test rig controlled by a specific
supervisor. So, Vasco Acyclism acts as a « black box », and communicates with
the supervisor via DLL functions.
The Human Machine Interface presented below is the “VASCO Acyclism supervisor” and
allows the control of the speed and acyclism.

of 8
From this software interface, the user can operate the following features:
Control the mean speed value of the motor :
 Set manually speed value, or predefined speed profile
Control the acyclism :
 Set manually order and level values, or 3D-chart appliance for the level
control versus the mean speed (from editable file)
 Order sweep feature
 Graphical overview for the raw dynamic speed measured on the motor shaft
Overall and autonomous security control :
 Motor stop on specific thresholds available on all parameters
 Max level acyclism template versus speed, defined in editable file
 Software and hardware watchdog to secure the communication between the
computer and the real time embedded module
Time chart display of the mean speed and level of acyclism
All the standard features of the VASCO Suite package are available, and
particularly :
 Easy creation of new user interfaces, including graph charts, digital displays…
 Data logging, on frequency up to the acquisition frequency, with assistant for
configuration
In the case of an application without supervision, all the control functions are operated from
an exchange table managed by a DLL module delivered with the package. The corresponding
parameters will have to be managed in the main supervisor software of the test rig.

Vega technical specification

Recommended

Recommended

More Related Content

Similar to Vega technical specification

Similar to Vega technical specification (20)

More from NERYS

More from NERYS (8)

Recently uploaded

Recently uploaded (20)

Vega technical specification