PMSG radial

This is a Permanent Magnet Synchronous Generator. This generator is currently used in the NTNU class TEP4175

Stator (armature)

Resistance scheme

Choose how the electrical resistance in the wire is found.

Options:

User defined (default):

You set the resistance explicitly.

From diameter:

You set the diameter of the (copper) wire. The resistance is then calculated using the default copper properties.

Diameter

The diameter of the copper wire.


  • Default value: 0.0015
  • Unit: $\text{m}$
  • Range: 0.0001 — 1

Resistance in wire

The resistance of the wire used in the coils.


  • Default value: 0.0112
  • Unit: ${Ω} \over {\text{m}}$
  • Range: 0 — 100

Number of turns per coil

The number of times the wire(s) is (are) wound for each coil (assumed the same for all coils.)


  • Default value: 28
  • Unit:
  • Range: 0 — 1000

Number of threads (wires)

The number of threads (wires) in parallel that are used in the stator coils.


  • Default value: 1
  • Unit:
  • Range: 0 — 10

Active length of coil side

For radial flux generator this corresponds to the length of coil that is overlapping with the magnet. Typically this is the length of the magnets, i.e. the length of the rotor.


  • Default value: 0.12
  • Unit: $\text{m}$
  • Range: 0 — 10

Winding factor

Factor that takes into account the fact that the coil width does not cover the pole width perfectly.


  • Default value: 1
  • Unit:
  • Range: 0.1 — 1

Corr. factor for terminal conn.

Correction factor to account for additional total resistance due to terminal connections. Used to calculate total resistance.


  • Default value: 1.14
  • Unit:
  • Range: 1 — 2

Corr. factor for increased temp.

Correction factor to account for additional total resistance due to temperature increase in coils. Used to calculate total resistance.


  • Default value: 1.08
  • Unit:
  • Range: 1 — 2

Flux density scheme

Choose how the flux density of the generator is set.

Options:

From magnets:

The flux density is caculated from magnet properties (this is only appplicable for an radial flux generator).

User defined (default):

The flux density must be specified by you in the Flux density input field.

Radial geometry

Dist. from axle to magnet surface

The distance from the center of the axle to the magnet surface on the rotor.


  • Default value: 0.039
  • Unit: $\text{m}$
  • Range: 0 — 100

Distance from pole surface

The (average) distance from pole surface (magnet on rotor) to the middle of the stator coils in radial direction.


  • Default value: 0.015
  • Unit: $\text{m}$
  • Range: 0 — 10

Number of phases

The radial PMSG generator can have 1 or 3 phases.

Options:

1:

1 phase

3 (default):

3 phases

Length factor

Correction of length to account for coil extension in the end-turn region of the coil.


  • Default value: 1.05
  • Unit:
  • Range: 0 — 10

Rotor and flux

Poles

The number of magnetic poles in the induction field. This is also the number of magnets.


Options:

2:

2 poles

4 (default):

4 poles

6:

6 poles

8:

8 poles

Flux density

The flux density in the middle of the stator coils.

  • Default value: 0.2
  • Unit: $\text{T}$
  • Range: 0 — 1e+09

Load and reference values

Load resistance per phase

This is the load resistance connected to the generator terminals. I.e. it is NOT a part of the generator itself.

  • Default value: 5
  • Unit: $Ω$
  • Range: 1 — 1e+12

Ref. number of turns per coil

Reference number of turns per coil. Used to calculate inductance.


  • Default value: 30
  • Unit:
  • Range: 1 — 1000

Ref. stator coils inductance per phase

Reference stator coils inductance per phase. Used to calculate inductance. The unit is Henry.


  • Default value: 0.0016
  • Unit: $\text{H}$
  • Range: 0 — 0.01

Ref. RPM for loss

Reference RPM for the friction and ventilation loss reference value. The loss is then calculated as proportional with RPM.

  • Default value: 1000
  • Unit: $\text{rpm}$
  • Range: 0 — 1e+06

Ref. friction and vent. loss

Reference friction and ventilation loss, i.e. extra loss taken into account. The value is the loss at the reference RPM. The loss is calculated as proportional with RPM.

  • Default value: 30
  • Unit: $\text{W}$
  • Range: 0 — 1e+06

Rating and efficiency

Rated power scheme

Decides how the rated electrical power of the generator is found.


Options:

From rotor area:

The rated electrical power is calculated based on the rotor area and the target (rated) wind speed.

User defined (default):

The rated electrical power is set by you.

Rated electrical power

The rated electrical power of the generator (i.e. power 'delivered to the grid'). The corresponding rated mechanical power is higher than this because the generator's efficiency is less than 100%.


  • Default value: 5e+06
  • Unit: $\text{W}$
  • Range: 0 — 1e+08

Target wind speed

The target wind speed to be used to calculate the target (or rated) mechanical and electrical power of the generator.

This parameter is only visible (and relevant) if Rated power scheme is set to From rotor area. In addition to this wind speed, the rotor area and the air density is used to calculate the target (rated) mechanical power

  • Default value: 12
  • Unit: ${\text{m}} \over {\text{s}}$
  • Range: 1 — 100

Rated RPM

The generator RPM when the rated power is reached. For higher RPM the blades will typically pitch to decrease the efficency and thus keep the power from exceeding the rated power.


  • Default value: 1173.7
  • Unit: $\text{rpm}$
  • Range: 0 — 1e+08

Efficiency factor

The efficiency of a generator is the ratio of input mechanical power to output electrical power. The efficiency factor is used to calculate the efficiency of the generator. The default behavior is that the efficiency is equal to the efficiency factor (and thus constant). However, some generators calculate an efficiency explicitly (e.g. the PMSG generators), and for these generators the calculated efficiency is reduced with the efficiency factor. If no such reduction is desired, the factor should be set to 1. The value of the efficiency factor ranges from 0.01 to 1.00 (1% to 100%).

  • Default value: 0.944
  • Unit:
  • Range: 0.01 — 1

Drivetrain efficiency factor

The drivetrain efficiency is the ratio of mechanical driving (aerodynamic) torque to braking (generator) torque. Thus mechanical loss in the drivetrain is: loss = 1 - efficiency factor. The generator torque is divided with the factor before it is applied (i.e. the generator torque is increased to model the mechanical losses). The value of the efficiency factor ranges from 0.01 to 1.00 (1% to 100%). A value of 1 means no losses.

  • Default value: 1
  • Unit:
  • Range: 0.01 — 1

Filtering

The rotational speed (RPM) of the generator can be filtered before use. Filtering is used to mitigate high-frequency excitation of the control systems, so filtering is recommended. The rotational speed is used to calculate the generator torque etc. and in the pitch control system to caclulate pitch.

Options:

None:

The real, physical RPM is used directly.

Recursive, single-pole (default):

Recursive, single-pole low-pass filter with exponential smoothing, see (Jonkman, 2009).

Corner frequency

The corner frequency. Used in a low pass-filter to calculate the filtered RPM. Suggested value is one-quarter of the blade's first edgewise natural frequency.

  • Default value: 0.25
  • Unit: $\text{Hz}$
  • Range: 0 — 1e+12