HIGH VOLTAGE TECHNIQUES electrostatic field analysis methods Assistant Professor Suna BOLAT Eastern Mediterranean University Department of Electric & Electronic Engineering
Jan 02, 2016
HIGH VOLTAGE TECHNIQUESelectrostatic field analysis methods
Assistant Professor Suna BOLAT
Eastern Mediterranean UniversityDepartment of Electric & Electronic Engineering
Electrostatic field analysis methods
1. Analytical calculations2. Analog methods3. Numerical methods
Analytical calculations
• Analytical solution of differential equations (Laplace, Poisson)• Conform transform• Schwarz – Christoffel transform• ...
Numerical methods
• Finite difference method• Finite element method• Boundary element method• Charge simulation method• Monte – Carlo method• Moment method
Experimental methods
• Electrolytic tank experiment• Semi-conductor paper method• Resistance simulation method• Grass seed method
Electrolytic tank experiment
Principle: static electric field has an analogy with current field. Application: • Create a scaled model of electrode system• Replace the dielectric with a conductive material • Determine the current field lines on conductive media• Draw the electric field lines perdendicular to them
Numerical methods
• Finite difference method
Principle: it leans on finite difference operations
All the derivatives are substituted by numerical representations.
Numerical methods
• Charge Simulation method
Principle: simulating the field between condutors by using simulation charges
Steps
• Place simulation charges outside of the region to be analyzed• Determine boundary points• Solve potential equation to calculate simulation charges for
boundary points• Control the value of charges• Calculate potential and electric field values for the desired
point using determined simulation charges
Accuracy of this method depends on
1. Type of the simulation charges2. Number of simulation charges3. Location of simulation charges4. Number of boundary points5. Location of boundary points
• After finding simulation charges, the value of the charges should be controlled
• Choose control points on known potentials&
Infinite line charge
For cylindrical systems
Pr0
𝜆=𝑄𝑙
l 𝑉 𝑃=𝜆2𝜋𝜀
ln𝑟0𝑟
r0: the distance between line charge and the point with 0 potentialr: the distance between charge and the point P
V = 0
Potential at my heart if I stand under a high voltage line
q
rHP
h
Conductor (line)
VL
Ground (earth)
Line simulation charge
V = 0
r
Suna