NVGate EVHV
Introduction and overview
Objectives
The objective of the EVHV module is to characterize the electromagnetic forces which are responsible of the noise emission of an electric motor. In particular it will be achieved through 2 main steps:
- eFrequencies determination and displays: they represent the characteristic frequencies that one may expect to find in the spectra. They are based on the specificities of the motor and depend of the RPM. For this reason, they are defined as harmonics.
- Spatiograms analysis and displays. Spatiograms are calculated based on measurements of accelerometers data distributed around the surface of the motor stator as shown in the picture below.
Sensors positioned for Spatiograms analysis
Each spatiogram is representative of a spatial distribution of the Electromagnetic forces. The sum of the participation of each spatiogram lead to the global vibration response. Determining the spatiogram responsible of the vibration harmonic that should be decreased is one of the major objectives of the EVHV module.
Separation of the response in a sum of participating wavenumbers
Getting started tutorial
The following tutorial is based on a provided project called "EVHV App Z12p2". To follow the steps below, one should preliminary place this project in the NVGate projects directory. When starting NVGate the following window will display. One should open a project and select "EVHV App Z12p2". This chapter is meant to provide a first global approach so to go through the main steps.
Open the project and load setup
Open project
Load Setup, last saved in project
The setup contains 2 layouts: Spectra and Spatio
Display layout 1 called Spectra
Checking the eFrequencies
EV/HV ribbon
eMachine should be clicked to access to the following dialog. At this stage, one can select the main characteristics of the eMotor.
Machine definition
When the machine is configured, one can press Save. The user goes automatically to the following dialog which is the "eMarkers" one.
eMarkers table
When pressing "Apply" the eMarkers will be displayed on the graphs of the current layout.
Spectra with the eMarkers
The eMarkers dialog should be closed by clicking on the cross on the top right hand-side.
Change the Layout to reach layout2 (called Spatio). Changing layout can be achieved by clicking on
which is located in the "Measurement" tab. A keyboard shortcut also exists: [CTRL+SPACE]
Displaying spatiograms
Icons linked to the display of the spatiograms
By opening the
positions editor, one can check the positions that were saved in the setup
The next step is to select a measurement. In the provided project and its contained measurement, spatiograms are already calculated. One should press the icon "select measurement" as shown below. In the dialog that follows, one should type, in the filtering area: for example, Z12. This will allow to find easily the appropriate measurement.
Selecting a measurement
From that point, the spatiograms for all wavenumbers (one spatiogram for each wavenumber) will be loaded and displayed. If they are not already calculated (as it is the case of the provided project).
Loading the Spatiograms
Following that action, the spatiograms are automatically scaled and displayed as follows.
Spatiograms displays
- The spatiograms are displayed here using the 3*3 configuration.
- The left top window is a reference spectrogram, the others are spatiograms
- The spatiograms automatically scaled using by default the "scale on max display option". It takes the Max of all results and set it as the maximum value of the scale.
- We want now to find the participating wavenumbers to certain harmonic which are of interest: As an example, we want to know what are the participating wavenumbers to H12 (Index 3). We see that the wavenumber 0 is clearly the highest contributor to H12.
- Applying the eMarkers, confirms emarker3 placed on the spatiogram thanks to the eMarkers.
Applying eMarkers to the Spatiograms
When using the displays:
- The windows configuration can be changed using
- The scaling can be updated using the Scale on Max
or the scale on displayed 
- The reference spectrogram (after selecting it) can be changed by using
- The wavenumber for each spatiogram can be changed by using
eFrequencies: from eMachine setup to eMarkers display
There are 2 main steps in the determination of the eFrequencies: the machine description achieved through the eMachine tab 
and the eMarkers tab 
where the eFrequencies are calculated.
eMachine
By clicking on 
, one displays the following dialog. Two main type of machine are configurable: PMSM machines and SCIM machines.
One can this configuration in the workbook of the project by pressing SAVE. After the SAVE the eMarkers tab opens automatically.
One can load an eMachine by pressing Load. When opening a project with its associated workbook, the eMachine saved in the workbook of that project will be automatically loaded.
The configuration parameters depend on the type of machine: they can be seen from the above windows
eMarkers
The eMarkers associated to the eMachine can be displayed by clicking on the following icon 
. From the table one can apply the eMarkers to the relevant graphs (spectra, spectrograms, spatiograms).
One can select them to be displayed in the graphs or not by activating/inactivating the VIEW checkbox.
When displaying eMarkers for a SCIM machine, one should setup the SLIP as well (between 0 and 1).
The tooltip of each eMarker will provide more detail about the eMarker. To see it, the eFrequencies editor needs to be active and one needs to hold the mouse one second over the harmonic.
One should read the table using the following notations:
- H: Harmonics of the rotating speed
- f: frequency
- fs: electric stator frequency
- r: wavenumbers
Spatiograms: from acquisition to display
Spatiograms allow to evaluate the contribution of each wavenumber to the vibration response. This is done by comparing all the spatiograms to one reference spectrogram. Spatiograms are calculated offline based on Instant spectra waterfalls using the motor RPMs or time as z axis reference. If the spatiograms are not contained in the project, they are automatically calculated when selecting the measurement.
In the spatiograms ribbon area the following actions can be achieved:
 |
Sensors positions | Allows to specify the positions of the accelerometers used to measure and calculate the spatiograms |
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Select inputs | Allows to access the inputs configuration. This is used to setup the instrument to acquire the data required to calculate the spatiograms |
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Load | Allows to load a measurement setup. One can for example reload a measurement setup which was used for a previous measurement. |
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Post analyze | Allows to post analyze a signal that was recorded |
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Select measurement | Allows to select the measurement containing the results. If the measurement already contains the spatiograms, they will be displayed. Otherwise they will be recalculated. |
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Scale on Max | Allows to rescale all spatiograms with the same Max scale. This max scale is the Max value contained in all spatiograms. This icon is available when a spatiogram is active. It is greyed when a reference spectrogram is active. |
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Scale on Displayed | Allows to rescale all spatiograms with the same Max scale. This max scale is the Max value contained in all the displayed spatiograms. This icon is available when a spatiogram is active. It is greyed when a reference spectrogram is active. |
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Windows configuration | Allows to choose the windows configurations. It also allows to refresh the display |
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Reference spectrogram selection | Allows to select the reference spectrogram to be displayed. The associated node is also shown as "Ref: [input label]: node number". This icon is only active when the spectrogram window is active |
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Spatiogram selection | Allows to select the spatiogram to be displayed by selecting its associated wavenumber. This icon is only active when the spectrogram window is active |
Sensors positions
To allow for spatiograms display the sensors positions need to be defined. This is achieved through the "Sensors Positions Editor" 
as displayed below.
The node defined in this window need to be the same ones as the ones used in the input's configuration.
The sensors position setup can be saved in the project workbook using the save button. It can be reloaded using the load button. When loading the project and its associated setup it is loaded as well.
Displaying Spatiograms
Spatiograms are displayed by first selecting the measurement using [
] and selecting the desired wavenumbers using [
]. Spatiograms are all displayed with a blue background to distinguish them specifically from the Spectrograms.
A shortcut allows to easily change wavenumbers: one should select the spatiogram to be modified and use [CTRL]+ [up and down arrows].
In order to fully use the content of the Spatiograms, one should apply the markers on the spatiograms and open the section using the left bottom cross. If the spatiogram contain eMarkers the bottom left section will show the profiles of the eMarkers.
Showing all eMarkers contained in Spatiogram 0
Selecting all active eMarkers contained in Spatiogram 0
The order section cursor is also active and can be used to compare eMarkers section to other order sections
| One can grab the cursor in each of the section to position it at the right frequency or right RPM (or time). The spatiograms will follow the preferences setup for the colormaps (dB by default). It can also be displayed as a 3D graph if desired [Lin by default]. As described earlier, and as the EVHV module is integrated in NVGate, it will benefit of all NVGate standard functions. For more details the NVGate user's manual should be consulted.  |
Order profile cursor |
Links
The links group allows to add any additional dedicated module which would be optionally written as a macro or an external program. It should be placed in the LINKS directory of NVGate. If done so, it will appear in the list.
- Selection of an external application or macro to be started
- Execute the application
Help
The help section allows to access 2 main features.
This icon allows to start the EVHV module user's manual
This icon allows to display the "About …" information
The EVHV module has been developed thanks to a cooperation between OROS and EOMYS who is specialist in Electromagnetic Noise and Vibration. Credits to EOMYS are given in this About dialog.
The About section
Contact us
This user's manual aims at providing the most complete information to help user's obtaining the most efficient use of the product. However, if complementary information is required there are various ways to contact OROS.
- First, OROS relies on a worldwide network of authorized representatives. OROS products and services are marketed worldwide in more than 35 countries.
Your local reseller can be found at https://www.oros.com/find-us/.
- If further assistance is needed, the Customer Care Team can be contacted using the information provided on the following link : https://www.oros.com/services/support/
The OROS Customer Care team