потери на гистерезис — это… Что такое потери на гистерезис? 

потери на гистерезис

• потери на гистерезис

english: hysteresis loss(es)

deutsch: Hysteresisverluste

français: pertes par hystérésis

Русско-англо-немецко-французский металлургический словарь. Основные термины. 2-е издание, стереотип. — М.: РУССО. Лопухов Г.А., Черкасов П.А., Мырцимов А.Ф.. 1996.

• потери в меди
• потери на испарение

Смотреть что такое «потери на гистерезис» в других словарях:

• потери на гистерезис — Потери на гистерезис. Обусловлены необратимыми процессами перемагничивания. Потери на гистерезис за один цикл перемагничивания (т.е. за один период изменения поля), отнесенные к единице объема вещества, определяются площадью статической петли… …   Справочник технического переводчика

• потери на гистерезис — histerezės nuostoliai statusas T sritis automatika atitikmenys: angl. hysteresis losses vok. Hysteresisverluste, m rus. потери на гистерезис, f pranc. pertes hystérésis, f …   Automatikos terminų žodynas

• потери на гистерезис — Потери мощности в магнитном материале вследствие гистерезиса при перемагничивании …   Политехнический терминологический толковый словарь

• потери на гистерезис при вращательном перемагничивании — — [Я.Н.Лугинский, М.С.Фези Жилинская, Ю.С.Кабиров. Англо русский словарь по электротехнике и электроэнергетике, Москва, 1999 г.] Тематики электротехника, основные понятия EN rotating hysteresis losses …   Справочник технического переводчика

• удельные магнитные потери на гистерезис — потери на гистерезис Часть удельных магнитных потерь, обусловленная явлением магнитного гистерезиса. [ГОСТ 19693 74] Тематики материалы магнитные Синонимы потери на гистерезис EN specific hysteresis losses DE spezifische Hystereseverluste FR… …   Справочник технического переводчика

• малые потери на гистерезис — — [Я.Н.Лугинский, М.С.Фези Жилинская, Ю.С.Кабиров. Англо русский словарь по электротехнике и электроэнергетике, Москва] Тематики электротехника, основные понятия EN low hysteresis losses …   Справочник технического переводчика

• ПОТЕРИ МАГНИТНЫЕ — электромагн. энергия, превращающаяся в теплоту в ферромагн. телах при периодич. перемагничивании их переменным магн. полем. П. м. Q за 1 цикл перемагничивания где V объём перемагничиваемого тела, H напряжённость магн. поля, В магн. индукция, jB… …   Физическая энциклопедия

• ГИСТЕРЕЗИС — (от греч. hysteresis отставание, запаздывание), явление, к рое состоит в том, что физ. величина, характеризующая состояние тела (напр., намагниченность), неоднозначно зависит от физ. величины, характеризующей внеш. условия (напр., магн. поля). Г …   Физическая энциклопедия

• потери на магнитный гистерезис — — [Я.Н.Лугинский, М.С.Фези Жилинская, Ю.С.Кабиров. Англо русский словарь по электротехнике и электроэнергетике, Москва, 1999 г.] Тематики электротехника, основные понятия EN magnetic hysteresis losses …   Справочник технического переводчика

• потери энергии на гистерезис — — [Я.Н.Лугинский, М.С.Фези Жилинская, Ю.С.Кабиров. Англо русский словарь по электротехнике и электроэнергетике, Москва, 1999 г.] Тематики электротехника, основные понятия EN hysteresis energy …   Справочник технического переводчика

• ГИСТЕРЕЗИС — (от греч. hysteros более поздний), название, даваемое ряду явлений, объединяемых тем общим свойством, что определенная величина является зависимой от предшествующего состояния исследуемой системы. Г. магнитный. Если поместить железный стержень… …   Большая медицинская энциклопедия

90000 Hysteresis Loss and Eddy Current Loss: What’s the Difference? 90001 90002 All electric motors experience rotational losses during the conversion of electrical power to mechanical power. These losses are generally categorized as magnetic losses, mechanical losses, copper losses, brush losses, or stray losses, depending on the underlying cause and mechanism. Included in the category of magnetic losses are two types — hysteresis loss and eddy current loss. 90003 90004 90005 Hysteresis loss 90006 90002 Hysteresis loss is caused by the magnetization and demagnetization of the core as current flows in the forward and reverse directions.As the magnetizing force (current) increases, the magnetic flux increases. But when the magnetizing force (current) is decreased, the magnetic flux does not decrease at the same rate, but less gradually. Therefore, when the magnetizing force reaches zero, the flux density still has a positive value. In order for the flux density to reach zero, the magnetizing force must be applied in the negative direction. 90003 90002 The relationship between the magnetizing force, H, and the flux density, B, is shown on a hysteresis curve, or loop.The area of ​​the hysteresis loop shows the energy required to complete a full cycle of magnetizing and de-magnetizing, and the area of ​​the loop represents the energy lost during this process. 90003 90011 90002 A hysteresis loop shows the relationship between the induced magnetic flux density (B) and the magnetizing force (H). It is often referred to as the B-H loop. 90013 90014 Image credit: NDT Resource Center 90015 90003 90002 The equation for hysteresis loss is given as: 90003 90002 90020 P 90021 b 90022 = η * B 90021 max 90022 90025 n 90026 * f * V 90027 90003 90002 90014 P 90021 b 90022 = hysteresis loss (W) 90015 90003 90002 90014 η = Steinmetz hysteresis coefficient, depending on material (J / m 90025 3 90026) 90015 90003 90002 90014 B 90021 max 90022 = maximum flux density (Wb / m 90025 2 90026) 90015 90003 90002 90014 n = Steinmetz exponent, ranges from 1.5 to 2.5, depending on material 90015 90003 90002 90014 f = frequency of magnetic reversals per second (Hz) 90015 90003 90002 90014 V = volume of magnetic material (m 90025 3 90026) 90015 90003 90004 90005 Eddy current losses 90006 90002 Eddy current losses are the result of Farady’s law, which states that, 90014 «Any change in the environment of a coil of wire will cause a voltage to be induced in the coil, regardless of how the magnetic change is produced.» 90015 Thus, when a motor core is rotated in a magnetic field, a voltage, or EMF, is induced in the coils.This induced EMF causes circulating currents to flow, referred to as eddy currents. The power loss caused by these currents is known as eddy current loss. 90003 90002 Motors armature cores use many, thin pieces of iron (referred to as «laminations»), rather than a single piece, because the resistance of individual pieces is higher than the resistance of one, solid piece. This higher resistance (due to smaller area per piece) reduces eddy currents, and in turn, eddy current losses. The laminations are insulated from each other with a lacquer coating to prevent the eddy currents from «jumping» from one lamination to another.90003 90072 90002 Eddy currents in laminated cores (right) are smaller than those in solid cores (left). 90013 90014 Image credit: wikipedia.org 90015 90003 90002 The equation for eddy current loss is given as: 90003 90002 90020 P 90027 90020 90021 e 90022 90027 90020 = K 90027 90020 90021 e 90022 90027 90020 * B 90021 max 90022 90027 90020 90025 2 90026 90027 90020 * f 90027 90020 90025 2 90026 90027 90020 * t 90027 90020 90025 2 90026 * V 90027 90003 90002 90014 P 90015 90014 90021 e 90022 90015 90014 = eddy current loss (W) 90015 90003 90002 90014 K 90015 90014 90021 e 90022 90015 90014 = eddy current constant 90015 90003 90002 90014 B = flux density (Wb / m 90025 2 90026) 90015 90003 90002 90014 f = frequency of magnetic reversals per second (Hz) 90015 90003 90002 90014 t = material thickness (m) 90015 90003 90002 90014 V = volume (m 90025 3 90026) 90015 90003 90004 90002 90014 Magnetic losses are so named because they depend on the magnetic paths in the motor, but they are also referred to as «core losses» and «iron losses.»90015 90003 .90000 Explanation of Hysteresis Loss & Eddy Current Losses in Transformers — Electrical Engineering 123 90001 90002 90003 Transformer 90004 is very simple and basic part of electrical system and considered most efficient of electrical components of machines. If we consider experimental models which are using superconducting windings then we may talk about achieving the the performance of 99.75 percent as well. In practice, energy is found to be lost in the windings, core and surrounding structures due to various causes as outlined below: 90005 90006 90007 90003 Copper Losses in Winding resistance: 90004 Windings are made up of copper wire which get heated due to Joule heating when 90003 current 90004 flows through them.effect When working at higher frequencies, skin effect and proximity effect add to the losses due to winding resistance 90012 90007 90003 Eddy Current Losses: 90004 An eddy current is an electric current set up by an alternating magnetic field. These losses arise from the fact that the core itself is composed of conducting material, so that the voltage induced in it by the varying flux produces circulating currents in the material. Eddy current loss depends upon the rate of change of flux as well as the resistance of the path, it is reasonable to expect this loss to vary as the square of both the maximum flux density and frequency.If the core is solid and made up from ferromagnetic materials, it effectively acts as a single short-circuited turn. Induced 90003 eddy currents 90004 therefore circulate within the core in a plane normal to the flux, and cause resistive heating of the core material. 90012 90007 90003 Hysteresis Losses: 90004 During each A.C. cycle, current flowing in the forward and reverse directions magnetizes and demagnetizes the core alternatively. Energy is lost in each hysteresis cycle within the magnetic core.Energy loss is dependent on the properties (e.g. coersivity) of particular core material and is proportional to the area of ​​the hysteresis loop (B-H curve). 90012 90007 90003 Magnetostriction Losses: 90004 The core undergoes minute physical expansion and contraction with the eachA.C. cycle due to the alternating magnetic field. This effect known as magnetostriction produces the familiar buzzing sound, and causes losses due to frictional heating in susceptible cores. 90012 90007 90003 Mechanical Losses: 90004 The alternating magnetic field causes fluctuations in the electromagnetic forces between the primary and secondary windings.These produce mechanical vibrations in nearby metal work and add to the buzzing noise. 90012 90007 90003 Stray Losses: 90004 All the magnetic field produced by the winding is not linked to the secondary winding due to the leakage of flux primary current It may induce eddy currents within nearby conductive objects, such as the transformer’s support and get converted to heat which is lost to the surroundings structure 90012 90007 90003 Power Loss due to the Cooling system: 90004 Cooling arrangement like cooling fans, is necessary generated in oil pumps or water-cooled heat exchangers for removing heat large power transformers.As the power consumption in the operation of the cooling system is unproductive, it is considered as power loss of the transformer. 90012 90039 90040 Physical Explanation of Hysteresis Loss of Transformers 90041 90002 The magnetic core of transformer is made of ‘Cold Rolled Grain Oriented Silicon Steel’. Steel is very good ferromagnetic material. This kind of materials are very sensitive to be magnetized. That means, whenever magnetic flux would pass through, it will behave like magnet. Ferromagnetic substances have numbers of domains in their structure.Domains are very small regions in the material structure, where all the dipoles are paralleled to same direction. In other words, the domains are like small permanent magnets situated randomly in the structure of substance. These domains are arranged inside the material structure in such a random manner, that net resultant magnetic field of the said material is zero. Whenever external magnetic field or mmf is applied to that substance, these randomly directed domains get arranged themselves in parallel to the axis of applied mmf.After removing this external mmf, maximum numbers of domains again come to random positions, but some of them still remain in their changed position. Because of these unchanged domains, the substance becomes slightly magnetized permanently. This magnetism is called «Spontaneous Magnetism». To neutralize this magnetism, some opposite mmf is required to be applied. The magneto motive force or mmf applied in the transformer core is alternating. For every cycle due to this domain reversal, there will be extra work done.For this reason, there will be a consumption of electrical energy which is known as 90003 Hysteresis loss of transformer 90004. 90005 90002 90005 90002 90003 Hysteresis 90004 is the ‘lagging’ effect of flux density B whenever there are changes in the magnetic field strength H. When an initially unmagnetized ferromagnetic material is subjected to a varying magnetic field strength H, the flux density B produced in the material varies . 90005 90002 90053 Hysteresis loss 90054 is associated with the phenomena of hysteresis and is an expression of the fact when ferromagnetic material is involved, not all the energy of the magnetic field is returned to the circuit when mmf is removed.It is known as hysteresis loss. The core of a transformer is subjected to an alternating 90003 magnetizing force 90004 and for each cycle of 90003 emf 90004 a hysteresis loop is traced out. 90005 90002 The lagging phenomenon of B behind H is called hysteresis. The tip of hysteresis loop can be joined to obtain the magnetization characteristics. 90005 90062 90007 Hysteresis loss results in a dissipation of energy which appears as a heating of the magnetic material. The energy loss associated with hysteresis is proportional to the area of ​​the hysteresis loop.90012 90007 For AC-excited devices the hysteresis loop is repeated every cycle of alternating current. Thus a hysteresis loop with a large area is often unsuitable since the energy loss would be considerable. 90012 90007 Silicon steel has a narrow hysteresis loop, and thus small hysteresis loss, and is suitable for transformer cores and rotating machine armatures. 90012 90069 90070 Hysteresis Loop 90071 90002 A hysteresis loop shows the relationship between the induced magnetic flux density (B) and the magnetizing force (H).It is often referred to as the B-H loop. 90005 90002 90005 90002 The area of ​​a hysteresis loop varies with the type of material. The area, and thus the energy loss, is much greater for hard materials than for soft materials. 90005 90062 90007 Hard material, which has a high remanence and a large coercivity. 90012 90007 Soft steel, which has a large remanence and small coercivity. 90012 90007 Ferrite, this being a ceramic-like magnetic substance made from oxides of iron, nickel, cobalt, magnesium, aluminium and mangenese; the hysteresis of ferrite is very small.90012 90069 90002 A disturbance in the alignment of the domains of a ferromagnetic material causes energy to be expended in taking it through a cycle of magnetization. This energy appears as heat in the specimen and is called the 90003 hysteresis loss. 90004 90005 90070 Equation & Explanation of Hysteresis Loss in Transformer 90071 90092 Determination of Hysteresis Loss 90093 90002 Consider a ring of ferromagnetic specimen of circumference L meter, cross — sectional area am 90095 2 90096 and N turns of insulated wire as shown in the picture beside, Let us consider, the current flowing through the coil is I amp, Magnetizing force, Let, the flux density at this instant is B, Therefore, total flux through the ring, Φ = BXa Wb As the current flowing through the solenoid is alternating, the flux produced in the iron ring is also alternating in nature, so the 90053 emf 90054 (e ‘) induced will be expressed as, 90005 90002 90005 90002 According to Lenz, s law this induced emf will oppose the flow of current, therefore, in order to maintain the current I in the coil, the source must supply an equal and opposite emf.Hence applied emf, 90005 90002 90005 90002 Energy consumed in short time dt, during which the flux density has changed, 90005 90002 90005 90002 Thus, total work done or energy consumed during one complete cycle of magnetism, 90005 90002 90005 90002 Now aL is the volume of the ring and H.dB is the area of ​​elementary strip of B — H curve shown in the figure above, 90005 90002 90005 90002 Therefore, Energy consumed per cycle = volume of the ring X area of ​​hysteresis loop. 90005 90092 Core Losses 90093 90002 The sum of hysteresis loss and eddy current losses is called core loss as both the losses occur within the core (magnetic material).For a given magnetic circuit with a core of ferromagnetic material, volume and thickness of the plates are constant and the total core loss can be expressed as follows. Core loss = Hysteresis loss + Eddy current loss It is rather easier to measure the core loss with the help of a wattmeter (W) by energizing the N turn coil from a 90003 sinusoidal voltage 90004 of known frequency. 90005 90070 Like this: 90071 90002 Like Loading … 90005 .90000 Hysteresis Loss | Eddy Current and Core Losses 90001 90002 The area within the hysteresis loop is a product of B and H and this area represents the energy per unit volume that must be used per magnetization cycle to move the domains. 90003 90004 90005 Hysteresis Loss 90006 90007 90002 With appropriate constants, the hysteresis loss can be given in watts per unit volume. An empirical relationship developed by Charles P. Steinmetz gives the hysteresis loss as; 90003 90002 $ {{P} _ {h}} = {{k} _ {h}} fB_ {m} ^ {n} $ 90003 90002 Where P 90013 h 90014 is the watts per unit volume, k 90013 h 90014 a constant term, f the number of magnetization cycles per second, B 90013 m 90014 the maximum flux density, and n the Steinmetz constant normally taken as 1.6. It follows that the greater the energy required to magnetize a sample, the greater the energy needed to demagnetize it. Large hysteresis loops are, therefore, required for permanent magnets, because the large hysteresis loop represents a large storage of energy. 90003 90004 90005 Eddy Current Loss 90006 90007 90002 A changing magnetic field induces an emf in a conducting material in that field. Such emf, within a magnetic core, create circulating or eddy currents. The eddy currents encounter the electrical resistance of the core producing power loss proportional to I 90025 2 90026 R losses.{2} $ 90003 90002 Where P 90013 e 90014 is the eddy current loss in watts per unit volume and k 90013 e 90014 a constant; f and B 90013 m 90014 are as previously defined. In order to reduce the magnitude of eddy currents and hence reduce the power loss in a core, magnetic cores are constructed by stacking thin laminations as shown in the following figure. 90037 90038 90003 90002 The laminations are insulated from each other by a thin coat of varnish. 90003 90002 In conclusion, the combined hysteresis and eddy current loss are known as the core losses.90003 90002 90003.90000 Petropedia — What is Hysteresis Loss? 90001 Toggle navigation Menu 90002 90003 Topics Oil Downstream Upstream Environment Exploration and Production Midstream Natural Gas 90004 90005.