# How to calculate e-NVH maps (torque/speed plane vibroacoustics)?

### Objectives

This article shows how to use MANATEE software for the simulation-driven NVH design of e-motors over the full operating range (torque/speed plane). MANATEE optimized models (e.g. subdomain model) and algorithms (e.g. Load Extrapolation and Electromagnetic Vibration Synthesis) can be used to synthesize in less than one minute acoustic noise and vibrations due to magnetic forces in the four quadrant operation of electric drives.

Noise map of a 48s8p IPMSM traction machine

### Principle

The operating points of the electric motor can be specified using three different templates of Excel sheets in MANATEE/IOFunctions folder:

• InputNoiseMapTemplate1: torque / speed plane is described by torque and current angle as a function of speed and current level with two sheets, T0=f(N0,I0) phi0=f(N0,I0)
• InputNoiseMapTemplate2: torque / speed plane is described by current vector as a function of torque and speed in two sheets, Id0=f(T0,N0) Iq0=f(T0,N0)
• InputNoiseMapTemplate3: torque / speed plane is described at several torque levels in three sheets for torque, current and load angle T0=f(N0,x) I0=f(N0,x) Gamma0=f(N0,x)

To quickly calculate electromagnetic excitations at all the operating points, the load extrapolation algorithm of MANATEE is advised.

TBC

### Scripting implementation

To activate NVH calculation over full operating points one must choose how the torque speed plane is described with

`Input.Simu.type_noise_map = 1;`

The name of the Excel sheet where torque / speed plane input parameters are defined is specified with

`Input.Simu.pathname_noise_map = 'InputNoiseMapTemplate.xls'`

The position of the Excel sheet data matrices can be further specificed with

`Input.Simu.range_noise_map = 'B2:AP122'`

For plots the maximum torque / speed curve characteristics (current level, speed, torque) in traction phase can be specified with

`Input.Simu.I_noise_map = [];`
`Input.Simu.N_noise_map = [];`
`Input.Simu.T_noise_map = [];`

The NVH map is generated by default using magnetic load extrapolation:

`Input.Simu.type_load_extrapolation_map = 1;`

The NVH map is resampled in torque/speed plane using the following discretization:

`Input.Simu.NS_map = 20;             % number of speed values along torque/speed curves for noise maps `
` Input.Simu.NT_map = 10;             % number of torque values along torque/speed <code> curves for noise maps `

### Plot commands

The following plot commands allow to post process NVH results in torque/speed plane: