Summary for: NTGridDQ < NTGrid

Class summary

NTGridDQ Speed-torque grid from d-q grid data.

Initialization:

grid = NTGridDQ(raw_grid, key, val) with any of the following:

• ‘U_DC’ : DC-link voltage. Default [] –> determine from base point.

• ‘turns_ratio’ : multiplier to adjust the motor turn count with.

• ‘base_speed’ : Base speed, see below.

• ‘base_torque’ : Base torque. Not used if U_DC is given. If not, then U_DC = terminal voltage at base point.

• ‘speed_range’ : speed range to initialize the grid for.

Properties

.U_DC - DC bus voltage. Changing this recomputes this.interpolant

.base_speed - Base speed

.base_torque - Base torque

.NTGridDQ/grid is a property.

.NTGridDQ/interpolant is a property.

.NTGridDQ/speed_range is a property.

.stack_length_ratio Stack length ratio.

A multiplier to apply on the stack length of the original design. The effects are computed with .set_stack_length_ratio.

.turns_ratio - Multiplier for motor turns. Changing this recomputes this.interpolant.

Methods

Class methods are listed below. Inherited methods are not included.

.parsing defaults

Documentation for NTGridDQ/NTGridDQ doc NTGridDQ

.NTGridDQ/compute_detailed is a function.

data = compute_detailed(this, Icoil, n)

.NTGridDQ/get_efficiency_grid is a function.

[etagrid, torque_grid, speed_grid, electrical_power] = get_efficiency_grid(this, varargin)

.NTGridDQ/get_grid is a function.

[Qint, torque_grid, speed_grid] = get_grid(this, q_name, varargin)

.get_op Interpolate operating point data

[eta, data] = get_op(this, n, T) where

• n : speed (rpm)

• T : torque (Nm)

[eta, I, Pcu, Physt, Peddy] = get_op(this, n, T, ‘mode’, mode)

• mode : operating mode, ‘motor’ / ‘generator’

Keyword arguments:

• ‘compute_detailed’ : (EXPERIMENTAL) compute detailed loss breakdown? Default: false.

Outputs:

• eta : efficiency (%)

and data, a structure with fields:

• I : 2x1 vector, [id; iq]. Phase quantities (not coil)

• Pcu

• Physt

• Peddy

• Pexcess

• W : losses

.get_speed_and_torque_grid Meshgrids for calculation.

.init_listeners Add property listeners.

.maximum_torque_at_speed Get maximum torque at given speed.

.maximum_torque_envelope Maximum torque vs speed curve.

[Tmax, n] = maximum_torque_envelope(this, I) returns the maximum torque vs speed curve (n, Tmax), within the given maximum current I (can be inf to obtain the absolute maximum torque).

The following key-value pairs are supported:

• speed_range : a 1x2 array of minimum and maximum speeds
• torque_range : a 1x2 array of minimum and maximum torques

.NTGridDQ/plot_map is a function.

Qint = plot_map(this, contour_name, varargin)

.plot_phase_current_limit Plots phase current limit.

h = plot_phase_current_limit(this, I, varargin) Plots the phase current contour for the rms current I (total phase current, parallel paths considered).

Returns the handle h to the contour line.

All input arguments are passed on to this.get_speed_and_torque_grid.

Additionally, the following key-value pairs are passed on to plot for actually drawing the contour (default values shown):

• ‘color’ : ‘r’
• ‘linewidth’ : 1
• ‘linestyle’ : ‘-‘
• ‘marker’ : ‘none’

.setup Initialization function

.save_efficiency_grid Save efficiency data.

save_efficiency_grid(this, filename)

save_efficiency_grid(this, filename, key, val) with

• ‘format’, ‘grid’/’columns’ : Output format. Only ‘columns’ supported right now.

• ‘sheet’, sheet_name : Sheet to save into.

• ‘range’, rng : Sheet range to save into. Default ‘A1’.

NOTE The exported (Id, Iq) currents are defined for the ‘coil frame’ using peak-scaled space vectors. Thus, the terminal RMS current is sqrt(Id^2 +Id^2) / sqrt(2) * number_of_parallel_paths for star connection, and sqrt(3) times that for delta

.set_stack_length_ratio Set stack length ratio.

set_stack_length_ratio(this, v) sets the stack length ratio and adjusts the results in this.grid accordingly, by multiplying the (unchanged) results from this.original_grid.

** NOTE AND WARNING : AC loss components are scaled linearly with the stack length. This is not perfectly accurate for ExtrudedBlockCircuit and similar losses.

Results are then recomputed with this.recompute.