The line to neutral voltage can be found by dividing the line to line voltage by 1. Saturable reactor for power flow control in electric transmission. The saturable transformer block model shown consists of three coupled windings wound on the same core. The reactor design is based on the gapped core concept, which gives a compact design with low losses and low total mass. The only one i have run into outside the military was an old, riveted dual box beam, overhead crane. Design methodologyapproach this paper proposes the structure and the working principle of the multivalve controlled saturable reactor mcsr.
The ac reactor features a magnetic core that can be deliberately saturated by means of a direct electric current in a control winding. The saturable core model is capable of simulating nonlinear transformer behavior including saturation, hysteresis, and. Pdf a simulation model for the saturable reactor researchgate. My goal is to simulate magamps in the far future, but after the initial experience with the saturable core reactor i am not even sure that ltspice is the correct tool. Since both the saturable reactor and the load may consist of resistive and reactive components, each device has an impedance that is the vector sum of its resistance and reactance. Beginning in 2007, first as sc power systems and from 2008 as zenergy power, inc. The theory of magnetic amplifiers is dated, but its simplistic design has benefits for modern applications. Peak flux density of the core shall be less than 1. Saturable core reactors current controlling device. Power magnetics supplies the most reliable saturable reactors available, using our design and manufacturing expertise to meet the demands of industry. Zp ultimately perfected the design of the saturated. The ideal operating point is the place in which a small increase in control current will cause a large increase in output power and a small decrease in control current will cause a large. As it is usually connected in series to the anode of the thyristor, it is also referred to as an anode reactor.
Overview of nuclear reactor systems and fundamentals someday man will harness the rise and fall of the tides, imprison the power of the sun, and release atomic power. Parallel tuned contactless power pickup using saturable core reactor. A conventional series iron core saturable reactor may also be used where. The method used to change the impedance of the saturable reactor is to change its inductance, thus its inductive reactance and therefore its impedance. Saturable core reactor a saturable core reactor is a magnetic core reactor coil whose reactance is controlled by changing the permeability of the core.
Abstract a mathematical representation for a polycrystalline, thintape, ferromagnetic metal is derived for the. Zenergy power has successfully designed, built, tested, and installed in the us electrical grid a saturable reactor fault current limiter. As the level of power supplied to the control winding is increased, the saturable reactor becomes more saturated. Saturable reactors are used in systems when a drop in full line voltage with complete linearity, a need to limit voltage spikes, sags and harmonics is required.
Figure 332 shows a saturable core reactor that is used to control the. Details on a saturable reactor that can be quickly assembled using two standard power transformers. As the first stage of the development plan, the appropriate saturable reactor structure should be presented and verified by. Generalized model for the saturable reactor core by herbert horace woodson submitted to the department of electrical engineering on may 14, 1956, in partial fulfillment of the requirements for the degree of doctor of science. A saturable reactor is a special type of inductor, the inductance of which can be controlled by the dc current through a second winding around the same core. The concept was introduced in the mid nineteen sixties. Its performance may be likened to a variable resistance in a dc circuit, except that its impedance is changed by controlling the magnetic saturation in an iron core by circulating a direct current. By continuing refinements, abb has learned to master critical operating parameters like vibrations and noise. The schematic diagram of this circuit is shown in figure 333. Furthermore, two saturable inductors can be aligned in antiparallel to create a magnetic amplifier. This reduces the impedance of the ac gate winding, and increase the amount of the supply voltage that is transferred to the load. Calculate the reactor inductance for a set of operating currents. Main applications sample problems saturable reactor.
This decreases inductive reactance and allows increased flow of the alternating current ac. This report presents the design of the settingless protective relay and its application to three different protection zones. The model takes into account the winding resistances r1 r2 r3 and the leakage inductances l1 l2 l3 as well as the magnetizing characteristics of the core, which is modeled by a resistance rm simulating the core active losses and a. Design, test and demonstration of saturable reactor high. The control winding is shown with five loops, and the load winding is shown with three loops. Design, test and demonstration of saturable core reactor. First and second output circuits are provided, each connected with a pair of output windings and each including two closed current paths consisting of the output winding, a common load, a common a. A saturable reactor capitalizes on this effect by forcing the core into a state of saturation with a strong magnetic field generated by. The double bar between the inductors stands for an iron core, and the symbol that cuts across the two windings is a.
Design, test and demonstration of saturable core reactor hts fault current limiter 1. Apart from the main limbs, the core has additional limbs carrying the reactor winding. Simplified transformer design and lower costs, offset. Its rdson will be in the, impedance of the reactor. Special transformers and applications transformers electronics. Albert nelson, franco moriconi, robert lombaerde 2. To calculate percent impedance you would need the inductance per phase value of the reactor given and the line to neutral value of the voltage. Mag amps regulate the output voltage with a saturable core reactor that exhibits a square bh loop. The concept of utilizing the saturablecore reactor for circuit control. Encyclopedia article about saturable core reactor by the free dictionary. A saturable reactor in electrical engineering is a special form of inductor where the magnetic core can be deliberately saturated by a direct. Pdf a simulation model for the saturable reactor antonio barili. Saturable core reactors an overview sciencedirect topics. A major application field of the saturable reactor is.
Osborne has been involved in a wide variety of saturable reactor design projects over the years. The saturable reactor cannot be modeled using a single spice primitive element. With the expansion of the grid, continuous reactive power compensation is vital for efficient operation of long transmission power lines or cables. Direct current detecting device using saturable reactors. In the case of a resistor it is very simple, but the solution does not apply to the remaining passive components. Saturable reactor for power flow control in electric. Magnetic amplifier technology involves unique techniques that can be tailored to match the fit, form, and function of your application. The percent impedance is defined as the voltage drop across the reactor as a percentage of nominal voltage.
Trench is a supplier of specialized electrical products and a recognized world leader in the design and manufacture of dry type air core reactors for all utility and industrial applications. The comprehensive directory provides access to full contact and ability information for sourcing professionals, engineers and researchers wishing to get information on reactors. It had run for many, many years before the scrs had failed. The value of bmax is chosen to be less than the worstcase saturation flux density bsat of the core material. A figure 8 shaped saturable reactor including a central leg, two lateral legs, an upper bar connecting the upper ends of each leg, a lower bar connecting the lower ends of each leg, and a coil wrapped around the central leg, the crosssectional area of the central leg at its narrowest point being less than the crosssectional areas of the two lateral legs combined so that the central leg. The standard for design criteria is a minimum life span of 20 years.
While it was a very simple system and easy to fix, no one knew what it was. A magnetic core for use in a saturable reactor made of an febased softmagnetic alloy comprising as essential alloying elements fe, cu and m, wherein m is at least one element selected from the group consisting of nb, w, ta, zr, hf, ti and mo, and having an alloy structure at least 50% in area ratio of which being fine crystalline. Therefore, a saturable core macro model, utilizing the isspice subcircuit feature, must be created. Implement two or threewinding saturable transformer. The operating principles of saturable reactors have been known for quite a long time, but it is only within the. Weve prepared the illustrations below to share six established saturable reactor element core and coil configurations. The reactor range goes from small kvar to large power reactors for variuos applications and includes also special reactors for unique challenges in. A saturable reactor in electrical engineering is a special form of inductor where the magnetic core can be deliberately saturated by a direct electric current in a control winding. It makes up a thyristor module by connecting multiple thyristors in series, and. Second, the design of the ac part of the fcl was refined from a sixlegged, pictureframe magnetic core spider design to a more compact and lighter design with better limiting capability. Pdf electric vehicle battery charger controlled by. Refinement of the flux path and core shape led to an efficient saturable reactor design requiring less ampereturns to saturate the core. Romba and others published electric vehicle battery charger controlled by magnetic core reactor to wireless power transfer system find, read and cite all the research.
Saturable reactor definition of saturable reactor by. Yunnan electric power grid is planning to development saturable reactors for 500 kv long distance ac transmission lines. On each of the saturable cores, a bias winding, a feedback winding and an output winding are wound. Saturable reactor definition is an ac reactor coil of variable but limited impedance because of magnetic core saturation by means of an auxiliary dc excitation coil abbreviation sr. Design, test and demonstration of saturable reactor. The reactor core will not saturate for currents less than 250% of the fundamental current rating of the reactor. The saturable reactor is designed to holdoff current until the switch. The welding transformer of the integral reactor type, shown in fig. Magnetic amplifiers for voltage regulation applications. Magnetic amplifierbased power flow controller osti. A saturable reactor for power flow control srpfc is a novel application of a concept well known to electronics and power electronics engineers that provides continuous modulation of line reactance by controlling the magnetization in a ferromagnetic core. Once saturated, the inductance of the saturable reactor drops dramatically.
All hunterdon transformers can be furnished with an optional ul recognized component electrical insulation system 75 industrial drive. Each saturable reactor s impedance is determined by the application of dc power to a control winding. L1 is the schematic symbol for a saturable core reactor. Special transformers and applications transformers. The valve reactor is an important part of the dc converter valve. With enough dc current, the magnetic core can be saturated, decreasing the inductance of the power winding in a controlled fashion. The permeability of the core is changed by varying a unidirectional flux flux in one direction through the core. I worked around saturable reactors in military and found them to be very reliable. The design of the saturable reactor re quires three. By using a saturable reactor in series with either a semiconductor or thyratron switch, the circuit designer can reduce losses in the switch and extend its life. Saturable core manufacturers, service companies and distributors are listed in this trusted and comprehensive vertical portal.