Superconductivity in Electric Power SectorSubmitted by- Submitted to-Ashish Soreng Dr. Abhimanyu Mohapatra7th Sem, 0901106140 Dr. Ranjan Kumar JenaElectrical Engg.
CONTENTSIntroductionTypes Of SCLTS vs HTSProperties Of SCEnergy ApplicationsConclusion
Introduction Superconductors are broadly viewed as materials which have negligible resistance to the flow of electricity under low temperature conditions . The phenomenon of superconductivity was first observed in mercury by the Dutch physicist Heike Kamerlingh Onnes in 1911 Discovery of High Temperature superconductors in 1986 reignited interest in superconducting Power application because of lower cooling costs.
What is Superconductivity?Superconductivity is a phenomenon observed in several metals and ceramic materials. When these materials are cooled to temperatures ranging from near absolute zero ( 0 K, -2730 C) to liquid nitrogen temperatures ( 77 K, -1960 C), their electrical resistance drops with a jump down to zero.The temperature at which electrical resistance is zero is called the critical temperature (Tc)
Types of Superconductors Used Low Temperature Superconductors (LTS) Ex- Nb3Sn, Nb3Ge High Temperature Superconductors (HTS) Ex- YBCO
Shortcomings of LTSCritical Temperatures are Very lowCost of cooling is very high using Liquid HeliumFor LTS TC < 20KAdvent of HTS Comparatively higher critical Temperatures HTS show superconductivity at or above −196 °C(77 K) i.e. Temperature of Liquid NitrogenLiquid Nitrogen is 15 times cheaper than liquid . Helium
Properties required for practical superconductors
ApplicationsSuperconducting Magnetic Energy StoragePower Transmission CableTransformersFault Current LimiterRotating Machines
Superconducting Magnetic Energy Storage (SMES)SMES is a device for storing and instantaneously discharging large quantities of power.It stores electric energy in the magnetic field generated by DC current flowing through a coiled wire.The SMES recharges within minutes and can repeat the charge/dischargesequence thousands of times withoutany degradation of the magnet.
Components Of SMES SystemSuperconductor CoilsPower Conditioning SystemCryogenically Cooled RefrigeratorVacuum Vessel
How Does It Work?Stores Electric Energy in Magnetic Field•Superconductors have zero resistance to DC electrical current at low temperaturesVery low Ohmic heat dissipationEnergy stored within the coil is given by
E= 5kJ E= 200kJ
Operation Of SMES SystemTransmission Voltage is reduced to several hundred VoltsAC is converted into DCDC Voltage charges the Superconducting CoilThe coil discharges and acts as a source of energy when AC Network requires power boost
Advantages Of SMES• Time Delay during charge and discharge is quite short• Very High Power is available almost instantaneously• Loss of power is less than other storage method• High Reliability.• Environmental friendly and highly efficient
Power Transmission CablesSince 10% to 15% of generated electricity is dissipated in resistive losses in transmission lines, the prospect of zero loss superconducting transmission lines is appealing In prototype superconducting transmission lines at Brookhaven National Laboratory, 1000 MW of power can be transported within an enclosure of diameter 40 cm.
TransformersHTS Transformer have low lossesSize and Weight are reduced by half.HTS Transformer are cooled by Cryo Coolers rather than dielectric flammable oil =>No Threat Of Fire hazards
Fault Current LimitersHTS Current Limiters Protects against disturbances such as Power Surges due to Lightning or Accidents.HTS coils absorb excess energy due to large pulse of current within MillisecondsHTS Current Limiters can effectively Limit the Current spikes Circuit Breaker must handle.
Rotating MachinesEfficiency improvements near 1%Decreased size and weight for equivalent ratingsImproved steady state and transient system performanceReduced life-cycle costs
ConclusionFurther R&D is in progress to synthesize new materials which might attain superconductivity at even room temperaturesSuch an invention can truly revolutionize the modern world of electronics, power & transportation