ONLINE ELECTRICAL ENGINEERING STUDY SITE

Magnetic Saturation

If we increase the mmf of a magnet, the flux density inside the core to of the is also increased. Now we can ask a question, whether there is any limitation of increasing flux density in the core of magnet with increasing applied mmf. The answer is yes. There is a limit beyond which there is no more sharp increase of flux density in the magnetic core even with sharp increase of mmf. If this limit does not exit it ≈ would be possible to squash huge flux in very small cross section of magnet and which can produce very strong magnet with very small size. But this is not the practical case. There is a limit although this limit is not very sharp one but it exists. This limit is called magnetic saturation.

Definitoion of Magnetic Saturation

The unit beyond which magnetic flux density in a magnetic area does not increase sharply further with increase of mmf.

Magnetic Saturation of Iron

It is well known to us that iron has very little reluctance. It is much smaller than reluctance of air. But above statement is only true when magnetic flux density is an iron core is less than specific limit. This limit may be from 1.6 to 1.8 Tesla depending upon the particular magnetic steel or iron in question.
Now if we try to work with flux density above this limit, the iron exhibits higher reluctance compared to that at low flux density. As a result the said iron or steel does not behave like good conductor of magnetic flux. At that situation much more mmf is required to drive the flux through the same iron core. More mmf means more ampere turn in the case of electromagnetic, hence this situation should avoid.

Relation between Reluctance and Flux Density

The graph below is shown the relation between effective reluctance of a magnetic material such as iron and its corresponding flux density. magnetic saturation In the above figure it is seen that, when flux density is within limit, the reluctance of the magnetic path is quite low but when it crosses certain value such as 2 Tesla as shown here, the reluctance of the same magnetic path is sharply increased.

As density of any quantity is related with volume, hence by increasing the cross section (i.e. volume) of the magnetic path one can reduce the effective flux density of the path for same given mmf.
To avoid the undesirable effect of the magnetic saturation, the size of the iron core suitably chose for a particular engineering application.
Generally volume of the iron or steel core of magnetic path in a machine is so chosen that flux density of the core does not cross the limit of 1.5 Tesla in normal operating conditions.




Comments/Feedbacks






Closely Related Articles Magnetic FieldMagnetic FluxMagnetic PermeabilityHysteresis LoopMagnetic Field and Magnetic Circuit | Magnetic MaterialsEnergy Stored in a Magnetic FieldStatic Electric Field | Electrostatic Induction A Current Carrying Conductor Within A Magnetic FieldMagnetic SusceptibilityHard Magnetic MaterialsSoft Magnetic MaterialsMagnetic Circuit with Air GapMore Related Articles Electric Current and Theory of Electricity | Heating and Magnetic EffectNature of ElectricityDrift Velocity Drift Current and Electron MobilityElectric Current and Voltage Division RuleRMS or Root Mean Square Value of AC SignalWorking Principle of a CapacitorQuality Factor of Inductor and CapacitorTransient Behavior of CapacitorCylindrical CapacitorSpherical CapacitorCapacitors in Series and ParallelHow to Test Capacitors?Electrical Conductance Conductivity of Metal Semiconductor and Insulator | Band TheoryWhat is Electrical Resistance?Resistivity and Laws of ResistanceProperties of Electric ConductorTemperature Coefficient of ResistanceResistance Variation with TemperatureSeries ResistanceActive and Passive Elements of Electrical CircuitElectrical DC Series and Parallel CircuitOhm's Law | Equation Formula and Limitation of Ohm's LawKirchhoff Current Law and Kirchhoff Voltage LawSingle and Multi Mesh AnalysisSuperposition TheoremThevenin Theorem and Thevenin Equivalent Voltage and ResistanceNorton Theorem | Norton Equivalent Current and ResistanceReciprocity TheoremNodal Analysis in Electric CircuitsMaximum Power Transfer TheoremDelta - Star transformation | Star - Delta TransformationElectric ChargeCoulombs Law | Explanation Statement Formulas Principle Limitation of Coulomb’s LawElectric Lines of ForceWhat is Electric Field?Electric Field Strength or Electric Field IntensityWhat is Flux? Types of Flux?Electric FluxElectric PotentialCapacitor and Capacitance | Types of CapacitorsEnergy Stored in CapacitorCharging a CapacitorDischarging a CapacitorFourier Series and Fourier TransformTrigonometric Fourier SeriesAnalysis of Exponential Fourier SeriesParity GeneratorElectric Circuit and Electrical Circuit ElementsSeries Parallel Battery CellsRL Series CircuitWhat is Inductor and Inductance | Theory of InductorRLC CircuitThree Phase Circuit | Star and Delta SystemRL Parallel CircuitRL Circuit Transfer Function Time Constant RL Circuit as FilterConstruction of AC Circuits and Working of AC CircuitsSeries RLC CircuitParallel RLC CircuitResistances in Series and Resistances in ParallelResonance in Series RLC CircuitPlanar and Non Planar Graphs of CircuitClipping CircuitMutual InductanceSelf InductanceSI System of UnitsElectrical International SymbolElectric Power Single and Three Phase Power Active Reactive ApparentVector Algebra | Vector DiagramRelationship of Line and Phase Voltages and Currents in a Star Connected SystemVector Diagram | Three Phase Vector DiagramTypes of Resistor Carbon Composition and Wire Wound ResistorVaristor Metal Oxide Varistor is Nonlinear ResistorCarbon Composition ResistorWire Wound ResistorVariable Resistors | Defination, Uses and Types of Variable ResistorsLight Dependent Resistor | LDR and Working Principle of LDRSource of Electrical EnergyVoltage SourceIdeal Dependent Independent Voltage Current SourceVoltage or Electric Potential DifferenceVoltage in SeriesVoltage in ParallelVoltage Drop CalculationVoltage DividerVoltage MultiplierVoltage DoublerVoltage RegulatorVoltage FollowerVoltage Regulator 7805Voltage to Current ConverterNew Articles Principle of Water Content Test of Insulating OilCollecting Oil Sample from Oil Immersed Electrical EquipmentCauses of Insulating Oil DeteriorationAcidity Test of Transformer Insulating OilMagnetic Flux