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Summary

PolyphaseWindingSpec Winding specification class.

Instantiation:

this = PolyphaseWindingSpec()

this = PolyphaseWindingSpec(dimensions)

Loads the number of slots from dimensions.Qs and pole-pair count from dimensions.p

Responsibilities:

  • contains winding-specifying parameters (turns, layers, etc)

  • assembles winding loop matrix for finite-element analysis

  • calculates total (half-)turn length and winding overhang

  • handles end-winding indcutance calculation

NOTE: End-winding inductance calculation only works for radial-flux machines for now.

PROPERTIES

  • FE_filling_factor Conductor filling factor for finite-element analysis.

Equal to 1 for solid-conductor models. Equal to this.filling_factor for stranded models.

  • N_layers - number of winding layers

  • N_series - number of turns per coil (slot and layer)

  • a - number of parallel paths

  • circuit - the CircuitBase object associated with this

  • PolyphaseWindingSpec/conductor_material is a property.

  • connection - connection

  • extra_phase_inductance - extra per-phase inductance

  • filling_factor Conductor area PER meshed conductor area.

Computed automatically from layout_spec.conductor_area if layout_spec.conductor area returns a real value. If it returns nan, fill factor has to be specified.

Note: for solid winding models, filling_factor will be ~equal to 1.

  • geometry - GeoBase object that this.circuit belongs to.

  • gross_filling_factor Gross filling factor

Gross conductor area (conductor + insulation) divided by the uninsulated winding area (winding window area - liners and layer insulations) .

  • half_of_turn_length - half of turn length

  • layout_matrix - winding layout matrix. See this.set_layout_matrix

  • layout_spec A WindingLayoutBase object specifying slot conductor layout.

Default: UniformLayout.

See RectangularLayout and RoundWireLayout for common alternatives.

Note that some Layouts only support stranded winding models, while others also enable solid models with each conductor modelled.

  • lew_given - given end-winding inductance per turn and per slot-segment

  • PolyphaseWindingSpec/number_of_dq_components is a property.

  • number_of_meshed_conductors_per_layer As the name suggests.

  • p - number of pole-pairs

  • phases - number of phases

  • property_warning_given - set to true to disable warnings about default properties used

  • series_conductor_length_per_phase - series-conductor length per-phase

  • series_turns_per_phase - number of series-turns per phase

  • slot_filling_factor Conductor area to winding area.

  • span - coil span

  • PolyphaseWindingSpec/strand_transposition_type is a property.

  • winding_model_type - modelling style, solid or stranded

  • wires_in_hand - number of wires in hand. Must be 1 for infinite stranded windings.

Methods

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

* PolyphaseWindingSpec Winding specification class.

Instantiation:

this = PolyphaseWindingSpec()

this = PolyphaseWindingSpec(dimensions)

Loads the number of slots from dimensions.Qs and pole-pair count from dimensions.p

Responsibilities:

  • contains winding-specifying parameters (turns, layers, etc)

  • assembles winding loop matrix for finite-element analysis

  • calculates total (half-)turn length and winding overhang

  • handles end-winding indcutance calculation

NOTE: End-winding inductance calculation only works for radial-flux machines for now.

* PolyphaseWindingSpec/average_phase_quantity_matrix is a function.

L = average_phase_quantity_matrix(this)

* bias_angle Bias angle for winding.

a = bias_angle(this)

Returns a rotation angle for the direct-quadrature transformation so that injecting d-axis current into the winding generates flux on the rotor d-axis.

* bind_to_model Bind to CircuitBase object.

* create_slot_geometry Create slot geometry.

Access method to WindingLayoutBase.create_slot_geometry

* dq Transformation to dq frame

y = dq(this, xy, angles)

* end_winding_inductance_matrix Compute EW inductance matrix.

Only works for radial flux machines.

* end_winding_loop_matrix End-winding loop matrix, slot-segment.

L = end_winding_loop_matrix(this)

Returns a number_of_slots x phases matrix, representing how many times each phase traverses each ‘slot segment’ = end-winding piece between two successive slots.

Only computed for one end of a radial-flux machine.

* end_winding_segment_inductance Inductance of one end-winding segment.

Calculation somewhat follows the approach given by Lipo, T.A. (*) for a random-wound winding. Iron modelled as perfect conductor, to accound for eddy damping.

(*) Introduction to AC Machine Design

Only works for radial-flux machines.

* independent_current_loop_matrix Current loop matrix for

independent coil currents.

* PolyphaseWindingSpec/line_current_matrix is a function.

M = line_current_matrix(this)

* PolyphaseWindingSpec/line_to_line_voltage_matrix is a function.

M = line_to_line_voltage_matrix(this)

* loop_matrix Loop matrix associated with this.

L = loop_matrix(this)

Returns a number_of_meshed_conductors_in_model x number_of_current_loops matrix, with the entries:

  • L(i, k) = +n : Loop k traverses conductor i to positive direction

  • L(i, k) = -n : Loop k traverses conductor i to positive direction

where:

  • number_of_meshed_conductors : Number of would-be meshed conductors per entire model. Equal to this.number_of_layers x this.number_of_meshed_conductors_per_layer x this.number_of_slots

  • number_of_current_loops : Number of current loops in winding; this.phases x this.wires_in_hand

  • n : number of stranded turns per meshed conductor. 1 for solid-conductor models, typically equal to this.N_series for stranded models.

* property_modified Adds the modified property to the list of modified

properties.

* save_to_excel Export winding specs.

save_to_excel(this, filename, varargin)

* set_layout_matrix Initialize winding layout matrix.

A layout matrix is a number_of_layers x number_of_slots matrix of integers, with values in range -phases…phases.

The entries of the layout matrix W are:

  • W(i, j) = +k : phase k goes through layer i, slot j, to positive direction:

  • W(i, j) = -k : phase k goes through layer i, slot j, to negative direction:

* show_unset_properties Show warning about unset properties (default

values).

* PolyphaseWindingSpec/symmetry_period is a function.

n = symmetry_period(this)

* PolyphaseWindingSpec/total_phase_quantity_matrix is a function.

L = total_phase_quantity_matrix(this)

* winding_angle Compute winding angle.

a = winding_angle(this)

Compute the stator winding angle i.e. rotation angle for the direct-quadrature space vector transformation (without considering the rotor bias angle) so that injecting d-axis current into the stator winding generates a cosinusoidal airgap flux density waveform (first peak of fundamental at y = 0, assuming non-salient rotor).

* xy Transform to phase quantities

y = xy(this, dq, angles), where

  • angles : (rotor) angles in electrical degrees.

y = xy(this, dq)