# PMSM Torque Estimator

Estimate permanent magnet synchronous machine torque

**Library:**Simscape / Electrical / Control / PMSM Control

## Description

The PMSM Torque Estimator block implements a torque estimator for permanent magnet synchronous machines (PMSM).

Use this block to estimate the mechanical torque of a motor when it is not directly
measurable. The block estimates torque using known machine parameters and the measured
phase current vector in the *dq0* reference frame.

Use the Park Transform
block to convert the measured phase current vector in the *abc*
reference frame to the *dq0* reference frame.

### Equations

The block estimates the mechanical torque
*T _{e}* of the PMSM using the torque
equation in the

*d*-

*q*rotor reference frame:

${T}_{e}=\frac{3p}{2}\left({\psi}_{m}{i}_{q}+\left({L}_{d}-{L}_{q}\right){i}_{d}{i}_{q}\right),$

where

*p*is the number of pole pairs of the PMSM.*ψ*is the flux linkage of the permanent magnet._{m}*L*and_{d}*L*are the_{q}*d*- and*q*-axis inductances of the PMSM.*i*and_{d}*i*are the_{q}*d*- and*q*-axis currents of the PMSM.

In practice, the machine parameters are not constants and depend on some physical phenomena. You can choose to define these parameters simply as constants or, more realistically, as functions of currents by using lookup tables.

### Assumptions

The machine parameters are known.

## Ports

### Input

### Output

## Parameters

## Model Examples

## Extended Capabilities

## Version History

**Introduced in R2017b**