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For a PMSM BLDCmachine configured to use the PMSM Variable Ld/Lq motor type, a JSON file is required to define the motor characteristics. The file must contain the following information:

Parameter (JSON key)

Value type

Unit

Description

Example

PolePairs

int

Number of pole pairs of the machine.

Code Block

language	json

"PolePairs": 2

DqTransformAngleOffset

double

degree

Angle offset applied to the DQ Transform, before Id and Iq are referenced to look up Ld, Lq, and Fm. A value of 0 indicates that the D axis is aligned with Phase A when the rotor angle θ=0. In other words, the active power reaches a maximum when Id is at a maximum. This is the default behavior.

For more information, see the DQ Transform description.

Code Block

language	json

"DqTransformAngleOffset": 0

Ra

double

Ohm

Phase A Resistance of the machine

Code Block
"Ra": 0.04

Rb

double

Ohm

Phase B Resistance of the machine

Code Block
"Rb": 0.04

Rc

double

Ohm

Phase C Resistance of the machine

Code Block
"Rc": 0.04

Id_axis

double[]

A

One dimensional array of the current values along the Direct axis of the stator.

This array must be the same size as Iq_axis, and its values must be arranged in ascending order.

Code Block
"Id_axis": [ -50.0, 0.0, 50.0 ],

Iq_axis

double[]

A

One dimensional array of the current values along the Quadratic axis of the stator.

This array must be the same size as Id_axis, and its values must be arranged in ascending order.

Code Block
"Iq_axis": [ -50.0, 0.0, 50.0 ],

Ld

double[][]

H

Two dimensional array of the Direct inductance values.

The size of this array must be n x n, where n is equal to the number of current values in Id_axis and Iq_axis.

Figure 1 below describes how the inductance values are mapped from the JSON file array to the Ld table.

Code Block

language	json

"Ld": [
  [
    0.0004,
    0.00042,
    0.00041
  ],
  [
    0.00041,
    0.00044,
    0.00043
  ],
  [
    0.0004,
    0.00042,
    0.000425
  ]
],

Lq

double[][]

H

Two dimensional array of the Quadratic inductance values.

The size of this array must be n x n, where n is equal to the number of current values in Id_axis and Iq_axis.

Figure 1 below describes how the inductance values are mapped from the JSON file array to the Lq table.

Code Block

language	json

"Lq": [
  [
    0.0004,
    0.00042,
    0.00041
  ],
  [
    0.00041,
    0.00044,
    0.00043
  ],
  [
    0.0004,
    0.00042,
    0.000425
  ]
],

Fm

double[][]

Wb

Two dimensional array of the Permanent Magnet Flux Linkage values.

The size of this array must be n x n, where n is equal to the number of current values in Id_axis and Iq_axis.

Figure 1 below describes how the inductance values are mapped from the JSON file array to the Permanent Magnet Flux Linkage table.

Code Block

language	json

"Fm": [
  [
    0.1,
    0.1,
    0.1
  ],
  [
    0.1,
    0.1,
    0.1
  ],
  [
    0.1,
    0.1,
    0.1
  ]
]

...

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Old Version 5

New Version 6

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