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Energy Losses in the Electrical Circuits Abeco “International” Ltd. V1.2 2010 Motors, lighting systems, wiring, mechanical terminations, distribution panels, protective devices, transformers, switchgear, and all end of circuit equipment experience a variety of resistance increasing inefficiencies that combine to create an average wattage loss • In a typical industrial facility of from 10% to 25% of total demanded power • • None of us expected such a large loss of energy in our companies Abeco “International” Ltd. V1.2 2010 The individual contributing loss components is a challenging engineering specialty, requiring extensive experience and knowledge of all the factors impacting the operating efficiencies of each of these components Abeco “International” Ltd. V1.2 2010 • Current dependent - heat losses: • on the Resistance (R) • on the Harmonic Distortion • on the Power Quality • on Reactive Power Abeco “International” Ltd. V1.2 2010 Losses in AC electrical circuits are dependent on the sum of all currents and resistance occurring in the circuit. Abeco “International” Ltd. V1.2 2010 • • These losses are a function of the length of the electron mean free path in the metal - wire. mean free path length depends on the number of electron collisions with: Dislocation Point defect injection Obcy atom • elements dependent on metal properties • Impurities in the lattice • Lattice imperfections (ie. Dislocations, point defects) • Grain boundaries, grain polarization... • elements dependent on temperature Phonons - vibrations of crystal lattice Phonons Abeco “International” Ltd. V1.2 2010 • Free electron scattering (collision) probability is proportional to the "space" occupied by the excited electron to the metal ion orbits • In the excited state “space” occupied is much, much larger - This means that decreasing the electron mean free path that is decreasing conductivity • Just pick up part of the energy of the electron in the outer orbit of the ion to reduce the “space” occupied by the ion in metal. Abeco “International” Ltd. V1.2 2010 Probable locations of the electron in the ground state Probable locations of the electron in an excited state • We use the features of the free electron and the photon as a particle and transfer part of the energy of the electron to the low-energy photon using one of the Compton scattering effects • In addition the Compton scattering effect is increaseng the wavelength of the electron. • Probability of free electron collision with the ion in the cross-section of electrical wire, with and without Power Optimizer ® Abeco “International” Ltd. V1.2 2010 Compton effect • Electrical properties of metal depend on its purity and production technology. • After manufacture of the wire is very difficult to change its electrical properties. with Power Optimizer Metal structure with Power Optimizer® We can dynamically increase the density of metal. Interacting metal by ferromagnetic modulator using PLZT ceramic properties. Increasing the density of the metal results in improved strength, electrical and thermal conductivity and permeability. • Abeco “International” Ltd. V1.2 2010 Metal structure w/o Power Optimizer® • Lower probability of collisions - less loss of energy, Less energy loss - less heat, • Less heat - lower temperature, • • Lower temperature - lattice vibration smaller • Smaller lattice vibration - lower probability of collisions • Less energy loss - less energy bill Abeco “International” Ltd. V1.2 2010 • Each harmonics current flowing through the resistance causes heat-losses. • As the harmonic frequency increases, resistance increases - the skin effect. • Reducing the harmonic content and skin effect , we reduce the energy heat losses. Very large impact on losses in the circuit with a fast solid state switches new instruments for measuring power quality, measure up to 3000 harmonics Abeco “International” Ltd. V1.2 2010 Harmonic distortion - current [A] • • • Because of the influence of the skin effect upon inductance the resistance is frequency-dependent The electromotive force produced in this way by self-inductance varies both in magnitude and phase through the crosssection of the conductor, being larger in the center and smaller towards the outside The current therefore tends to crowd into those parts of the conductor in which the opposing EMF is a minimum; that is, into the skin of a conductor Abeco “International” Ltd. V1.2 2010 l cable length, r conductor radius, µ0 magnetic field constant, µr relative permeability, σ conductivity and ω angular frequency (ω=2πf) The wire cross-section low frequency F > 1KHz F > 100 KHz • In the electric motors • Reduction of self-inductive effect and stray losses • content of some of the harmonic, reduces the reverse torque of motor • reduces the temperature of motor winding which extends its life time Abeco “International” Ltd. V1.2 2010 Inductive load - draws current has two components ◦ Real current I supplies Real Power P [W] to the load - to perform work. loss ∆Pr=I2R ◦ Reactive current Ir supplies Reactive Power Q[var] to the load - energize the magnetic field of load (i.e.. motor) - loss ∆Pre=Ir2R=(Q/U)2R Both currents supply Apparent Power S [VA] to the load - loss ∆P=∆Pr+∆Pre Abeco “International” Ltd. V1.2 2010 Reactive Power To get 1 KW of real power if PF = 1,1 KVA apparent power needs to be transferred To get 1 KW of real power if PF = 0.2,5 KVA apparent power needs to be transferred ◦ This apparent power must be transmitted to the load, and is subject to the usual distributed losses " Abeco “International” Ltd. V1.2 2010 • In addition to reducing energy losses we would increase the efficiency of conversion of electricity to other energies. • mechanical • Heat • light Abeco “International” Ltd. V1.2 2010 Abeco “International” Ltd. V1.2 2010 Is regular three-dimensional lattice of ions containing a large number of electrons that are free to flow throughout the whole metal. Abeco “International” Ltd. V1.2 2010 • The movement of charges constitutes an electrical current • In metals flowing electrical charges = free electrons • No external electric field applied free electrons move randomly = no current flow Abeco “International” Ltd. V1.2 2010 random move of the electrons The electric field causes the electrons move opposite to the direction of the field Flow of the electrons = electrical current Abeco “International” Ltd. V1.2 2010 E Arrenged Flow of Electrones The electric current flow I is determined in amperes A. I - the amount of electrical charge passing through the cross-section of the wire in time. j - current density the amount of electricity flowing through the wire cross-section Abeco “International” Ltd. V1.2 2010 • Average speed of electric charges constituting the current = 1A in the copper wire with cross section = 1mm2 • Cu • 29 protons and 27 core electrons and 2 - valence electrons • molar mass of copper =63.5 gm/mol density of copper= 9 gm/cm3 • number of free electrons per mol = 6.02 * 1023/mol , in 1 mm3 =1.7*1020 el/mm3 • charge in 1 mm3 = 1.7*1020 *1.6*10-19 =27 C/mm3 • Average speed of charge - 1A = 1C/s then 1/27 mm/s Abeco “International” Ltd. V1.2 2010 T Charge density " Collision time" Factor from the acceleration in electric field Abeco “International” Ltd. V1.2 2010 In the presence of an electric field the free electrons would have an acceleration and its velocity would steadily increase in proportion to the field E The electron is accelerated and then makes collision with a lattice ion and start accelerated again. Part of the electron energy is transferred to ion and turns into heat. (vibrations of the ion = Phonons) Abeco “International” Ltd. V1.2 2010 Collision with ions a c c e l e r a ti o n Time t Collision time The average distance between collisions is called the Mean Free Path • • Each collision causes the loss of energy sources needs to provide adequate amount of energy to the Load the longer mean free path is, it is less energy loss. Collision with ions a c c e l e r a ti o n Time t Collision time Abeco “International” Ltd. V1.2 2010 • Average speed and energy of charges (electrons) is constant • For the transport of charges Q along the electrical circuit, the electric field E has to perform the work W. • The same is the loss of charges Q along the electrical circuit • We need the Power P of the source of electric field Abeco “International” Ltd. V1.2 2010 ∆P=i2*(R+R1+R2)= 69.12W + V R1 54W R = 10 Ohm ∆P=I2R =54W R2 - R1 and R2 =1 Ohm R1=R2=0 Ohm I=2.4 A Electric potential Power taken from the energy source to perform of the same amount of work by the resistor R = 54W or 69.12W Abeco “International” Ltd. V1.2 2010 • Power of each electrical equipment is determined by manufacturer at a given voltage. Smaller losses greater voltage! • All energy losses in the electrical circuit have an impact on the efficient use of electricity. Abeco “International” Ltd. V1.2 2010 Abeco “International” Ltd. V1.2 2010