GK V96
The design, the construction and the analysis of the performances of electrical machines demand specialised and reliable tools for electromagnetic simulation.
Méditech owns a complete modelling system, which integrates industrial CAD software as well as proper development sofware. We use programs for 3D simulation, which use the latest numerical techniques (adaptive meshing, nodal and edge elements…).
The program GKV96, developed by Méditech, is a 2D simulation program for electromagnetic fields by the finite element method. It uses a magnetic vector potential and modified electrical scalar potential formulation. GK V96 was specially designed to respond to the demand in design of electrical machines.
Among the developed modules are:
|
|
We also developed a lot of other modules for different applications (Electrostatic, Thermodynamic).
Magnetic 2d static
The fields are time independent. For these problems the program finds a solution for the magnetic vector potential to the equation rot(H) =J.
2D Cartesian coordinate system
The fields only depend on x and y. The program calculates Az(x,y), the z component of the magnetic vector potential.
Finite elements
Triangles with 3 or 6 nodes (linear or quadratic
interpolation)
Quadrilaterals with 4 or 8 nodes (linear or
quadratic interpolation)
Materials
The materials can have magnetic and electric properties:
Magnetic linear (constant permeability)
conducting or non-conducting,
Magnetic non linear (B(H)) conducting or
non-conducting,
Permanent magnetic (reversible permeability,
coercive force),
Non-magnetic conducting (resistivity) or
insulating.
Current sources
Current densities Jz, supposed as constant in different zones.
Results
Magnetic vector potential Az at the nodes,
Mean flux density vector B in the element,
Mean current density vector in the element,
Stored magnetic energy in the element,
Losses density (resistive losses) in the
element,
Total current in groups of elements,
Total stored magnetic energy in groups of
elements,
Resistive losses in groups of elements.
Magnetic 2D dynamic with and without large motion
The fields are time dependent. A large motion between rotor and stator is possible. For these problems the program finds a solution for the magnetic vector potential to the equation rot(H(t)) =J(t).
2D Cartesian coordinate system
The fields depend on x, y and the time. A relative movement between different zones of the mesh is possible. The program calculates Az(x,y,t ), z component of the magnetic vector potential, and Y(t) (modified electric potential: time integrated electric scalar potential) for circuit elements.
Finite elements
Triangles with 3 or 6 nodes (linear or
quadratic interpolation)
Quadrilaterals with 4 or 8 nodes (linear or
quadratic interpolation)
Circuit elements
Materials
The materials can have magnetic and electric properties:
Magnetic linear (constant permeability)
conducting or non-conducting,
Magnetic non linear (B(H)) conducting or
non-conducting,
Permanent magnetic (reversible permeability,
coercive force),
Non-magnetic conducting (resistivity, number
of conductors) or insulating.
Current and voltage sources
Current densities Jz, constant in different zones.
The finite elements can be connected to circuit elements.
Electrical circuits:
Electrical circuits are composed of circuit elements, which are connected by nodes. These elements can be connected to zones of finite elements.
The circuit elements are:
Resistances,
Inductors,
Capacitors,
EMF.
EMF can have different functions:
Sinus,
Spectral decomposition,
Step functions,
Constant value.
Results
For every time step the program can calculate:
Magnetic vector potential Az and electrical
potential at the nodes,
Mean flux density vector B in the element,
Mean current density vector in the element,
Stored magnetic energy in the element,
Loss density (resistive losses) in the
element,
Total current in groups of elements,
Voltage drop across circuit elements and
groups of finite elements,
Electromagnetic torque,
Total stored magnetic energy in groups of elements,
Instantaneous power in circuit elements,
Resistive losses in groups of elements.
Large motion 2D
A concentric rotational movement between rotor and stator is possible when dynamic modelling.
Complex
All fields follow sinus functions (single frequency). No motion is possible. All unknowns are complexes.
The magnetic vector potential is Az.ejwt.
2D Cartesian coordinate system
The fields depend of x and y and have a common frequency.
The unknowns are identical to the dynamic module.
Finite elements
Identical to the dynamic module.
Materials
The materials can have magnetic and electric properties:
Magnetic linear (constant permeability)
conducting or non-conducting,
Magnetic non linear (B(H)) conducting or
non-conducting,
Non-magnetic conducting (resistivity, number
of conductors) or insulating.
Current and voltage sources
The current and voltage sources are identical to the dynamic module with the restriction to sinus functions of one frequency.
Results
The results are identical to the dynamic module, additionally in amplitude and phase.
Examples:
|
|
Synchronous motor
Calculation of the time dependant magneto dynamic forces acting at no load on the stator iron for vibration problem.
|
|
|
Top of the page Other examples
Permanent magnet motor
Determination of losses in the permanent magnet due to stator slots and harmonics in stator current up to 48000rpm.
|
|
|
|
Top of the page Other examples
Asynchronous Motor
Start-up (Iron saturation due to zig zag leakage flux) of a double Squirrel cage motor: verification of locked rotor current and torque.
|
|
|
Top of the page Other examples
|
|
|
|
