
HIFREQ
Electromagnetic Fields Analysis
HIFREQ is a unique engineering tool that can solve any electromagnetic problem involving a network of arbitrarily oriented aboveground and buried conductors energized by any number of current and voltage sources. HIFREQ is a dream come true for those who have to tackle complex electromagnetic problems involving conductor networks, including bare and/or coated conductors, coaxial or multicore cables, transformers, lumped resistors, inductors and capacitors, etc. HIFREQ is certainly the only engineering software module that can provide accurate solutions to transient and steadystate problems in the frequency range of 0 to thousands of megahertz to analyze buried and above ground currentcarrying conductor networks. It computes electric and magnetic fields in the air and soil, as well as conductor and soil potentials, and the current distribution in the soil and in the the conductors.
Technical Highlights
HIFREQ calculates the scalar potential, and the electric and magnetic fields due to an energized conductor network, as well as the current distribution in the conductors. HIFREQ was designed to solve problems accurately, without ignoring soil characteristics, conductors in the soil, or nonenergized metallic structures in air or soil. With HIFREQ you can:
 Study transients (such as lightning, switching surges and any conceivable surge problem) and high frequency disturbances on power system networks, structures and grounding systems at frequencies ranging from a few hertz to hundreds of megahertz.
 Calculate current and potential distributions in all conductors, EMF values in air and soil and voltages along well defined paths due to buried or inair power system conductors and structures.
 Calculate electromagnetic interference to pipelines, communication lines, etc., in one single step. Inductive, capacitive and conductive effects are accounted for simultaneously!
 Analyze cathodic protection problems and optimize rectifier capacities and locations on protected structures extending up to hundreds of km.
 Use FFTSES, a fully integrated and automated Fourier Transform tool, to visualize electromagnetic fields in the time domain.
 Study reradiation interference or calculate current distributions in monopole, quarterwave, and other antenna structures excited at frequencies reaching hundreds of megahertz.
 Calculate induction between arbitrary circuits at low and high frequencies and during surge conditions. Determine self and mutual impedances as well as capacitances of these circuits regardless of whether they located above or below ground!
HIFREQ gives you the following powerful and flexible features.
 Choose to have the software calculate the current distribution in the conductors automatically based on a set of impressed currents or source voltages, or specify the currents in the conductors explicitly.
 Investigate the effects of different phenomena individually: you can choose, for example to ignore induction effects, or current leakage at the ends of conductors.
 Model horizontally layered soil structures.
 Select a combination of four network energization methods: current injections, voltage sources, GPR energizations (for which the voltage at a point is clamped at a specified value) and externally applied electric field.
 Model single phase transformers as well as various type of threephase transformers.
 Define coaxial or pipetype cables in the network.
 Model lumped parameters such as a resistor, inductor or capacitor within a conductor.
 Support bare and coated conductors.
Further details
Voltage Energization
A Voltage energization represents a simple model for an AC voltage generator. When a voltage energization is specified on a conductor, the voltage increases along this conductor by an amount specified by the user. By connecting one end of this generator to the ground, the other end can be kept at the desired potential.
Lumped Impedances
It is possible to define the impedance of a conductor by simply attaching a series combination of a resistance, an inductance and a capacitance to the conductor. The program then computes the resulting load impedance at the energization frequency.
Potential Energization
A Potential energization can be used to force the scalar potential at the surface of a conductor (GPR) to be at a user specified value. The current flowing in the conductor is automatically adjusted in order to achieve this potential.
The Voltage and Potential energizations are often used, together with lumped impedances, to establish appropriate current and voltage levels on transmission lines modeled in HIFREQ. Their usage is not limited to this particular application, however. In fact, it is possible to use these features in HIFREQ to do conventional circuit theory calculations!
Coating
All conductors in HIFREQ can be insulated from the surrounding medium by a physical (i.e. leaky) coating, i.e. a layer of a dielectric material of userdefined thickness, resistivity, permittivity, and permeability.
AppliedField
The response of a conductor network to the presence of an externally applied electromagnetic field can be very interesting, particularly to simulate the effects of distant lightning strikes or geomagnetic disturbances. HIFREQ can carry out such calculations for two different forms of externally applied field: a constant (electrostatic) electric field or a general electromagnetic planewave. The usersupplied characteristics of the applied field in the air are used to compute the applied field everywhere else, as well as the current distribution in the network. The scattered fields caused by this circulation of current can be obtained.
Transformers
HIFREQ offers a singlephase transformer model that makes it easy to study systems with multiple voltage levels or the many other applications where transformers are used in the power industry. Two kinds of transformers, namely Ideal and General transformers, can be defined. The ideal transformer is perfect, lossless and infinite in mutual coupling, and is characterized by a Voltage Ratio. The general transformer model takes into account the self and mutual inductances, resistances and the magnetic flux leakage. Other transformers, such as autotransformers and threephase transformers, can be built by combining several singlephase transformers together. A database of prebuilt transformers offers the most commonly occurring types of connections available in the industry.
Cables
With HIFREQ, modeling complex, multiphase cables is as simple as modeling a single solid conductor. HIFREQ allows you to define one or more types of concentric (coaxial) or pipetype (multicore) cables. These cable types can then be assigned to network conductors turning those conductors into cables. Coaxial cables can consist of up to three distinct components (the core, sheath and armour) with arbitrary electrical characteristics. Multicore cables can include any number of coaxial cables surrounded by a pipe enclosure with arbitrary characteristics. The characteristics of the insulating material between the cable components and inside the pipe enclosure can also be specified.

