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Presentation earthing


<p>i1</p> <p>i2</p> <p>V=N</p> <p>Faradays Laws of Electromagnetic Induction</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>Faradays law</p> <p>So we have the following : 1)</p> <p>2)</p> <p>i1</p> <p>i2</p> <p>i1 i2</p> <p>E1</p> <p>E2</p> <p>E1</p> <p>E2</p> <p>N1: N2 Step Up N1 &lt; N2</p> <p>N1 : N2 Step Down N1 &gt; N2</p> <p>E1</p> <p>E2</p> <p>N1 : N2</p> <p>E1</p> <p>E2</p> <p>N1 : N2</p> <p>THE VOLTAGE MEASURED FROM THE DOT END TO THE NON DOT END IS IN THE SAME PHASE</p> <p>C A</p> <p>VAB</p> <p>B D</p> <p>C A</p> <p>VAB</p> <p>B D</p> <p>VCD</p> <p>C A</p> <p>VAB</p> <p>B D</p> <p>VCD</p> <p>Primary</p> <p>Secondary</p> <p>Primary</p> <p>Secondary</p> <p>N1 : N2 1:n</p> <p>i2 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>i2 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>i2 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>EG , E1</p> <p>i2 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>As , E1 and E2 has the same dot polarity , So E1 is in phase with E2 So in the phasor diagram</p> <p>Primary</p> <p>Secondary E2 Z2</p> <p>EG</p> <p>E1</p> <p>N1 : N2 1:n</p> <p>EG , E1</p> <p>i2 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>E2</p> <p>EG , E1</p> <p>i2 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>i2 lags or leads by E2 depends upon the impendence i2 lags E2 if it is inductive load i2 leads E2 if it is Capacitive load</p> <p>Let us consider , Z2 be the inductive Load so i2 lags E2</p> <p>i2 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>E2</p> <p>EG , E1</p> <p>i2</p> <p>i1 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>So,E2 = n E1i1 =ni2 EG , E1 E2 = nE1</p> <p>i2</p> <p>So,i1 = n i2</p> <p>Inside the core there is a flux m linking Both primary and secondary</p> <p>i1 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>So,E2 = n E1EG , E1 E2 = nE1</p> <p>i1 =ni2</p> <p>i2</p> <p>So,i1 = n i2</p> <p>According to the Faradays Law ,</p> <p>= N1 j m Due to j operator m moves From E1 by clockwise of by 90 So We have in Phasor diagram</p> <p>i1 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>So,E2 = n E1i1 =ni2 EG , E1 E2 = nE1</p> <p>i2</p> <p>So,i1 = n i2</p> <p>i1 Primary Secondary</p> <p>i2</p> <p>EG</p> <p>E1</p> <p>E2</p> <p>Z2</p> <p>N1 : N2 1:n</p> <p>The Phasor Diagram of an Ideal Transformer</p> <p>So,E2 = n E1</p> <p>i1 =ni2</p> <p>EG , E1 E2 = nE1</p> <p>i2</p> <p>So,i1 = n i2</p> <p>Power Handling Capacity Electrical Parameters i1 , V1 , Power , Turns (N1, N2) Mechanical or Physical dimensions Core Sizes , Sizes of wire gages etc</p> <p>To determine the power handling capacity of the transformer we have to mapping the Relationship between Electrical Parameters and Mechanical dimension</p> <p>the practical transformer the coils are terminated by soldering , the rectangular solid block is the core , in this case the core is CRGO( cold rolled grained oriented) silicon steel ,as the steel is conductive , we have lot of eddy currents in the solid steel , to reduce the cross-sectional area of the eddy current path , to increase the resistance for the eddy current path the lamination have been put into it , all the practical transformer has solid bulk of core is laminated , its all are pocket is vacuumed and it is varnished and its darkish color is due to the varnish coating , well you see the winding in the centre which goes to the central limb, now this consists of both primary and secondary winding the primary goes first and then the secondary</p> <p> Electrical Equipment wUZ U avZe mvidmwUZ ground voltage G eRvq _vK BnvZ Zvi msk Avmv gvbylwU ` Ubv nZ iv cvq | N Bnv GKwU wb-impedance evavhy path Zix Ki hvnvZ eRcvZ wKsev Kvb aibi BjKwUK mvR Electrical Equipment ev KgiZ ewUK wZ bv Ki wb-impedance evavhy path -wU w`q gvwUZ Pj hvq|</p> <p>AvRKi welq t 1. Uvdigvii Avw_s Ges jvW evjws Gi iZ | 2. Uvdigvii cvivjvj Acvikb Ges jvwWs cwZ|</p> <p>Avw_s Gi Arrangement : AvvwZK Standard IEC 60364 3 wU Arrangement wb`wkZ R KiQ hvnv `yB Ai w`q wPwZ Kiv nqQ t c_g AiwU w`q Earth Ges Power Supply Equipment ( Generator or Transformer) Connection eySvq t T mivmwi Earth Gi mv_ mshy| I Earth Gi mv_ mshy Via high impedance wZxq AiwU w`q Earth Ges Electrical Device Connection eySvq t T mivmwi Earth Gi mv_ mshy| N Earth Gi mv_ mshy Power Supply Equipment Gi Earthing - Gi gvag</p> <p>TN bUIqvK tdRq</p> <p>wbDUvj</p> <p>Equipment-Gi Avw_s</p> <p>TN bUIqvK Earthing System G Transformer - Gi Star point Earthing - Gi mv_ Equipment-wU mshy _vK|</p> <p>TN bUIqvK Gi cKvif` t</p> <p>TT bUIqvK t</p> <p>dRq</p> <p>wbDUvj</p> <p>Equipment-Gi Avw_s</p> <p>Power Supply Equipment-Gi Avw_s</p> <p>IT bUIqvK dRq</p> <p>Equipment-Gi Avw_s</p> <p>All the power station are made on ground grids , the grid consists of metal rods driven to the ground and this is connected to the metallic mesh met , all this area is the same ground potential . the main reason is that for safety.</p> <p>Switch Gear-1</p> <p>Switch Gear-2</p> <p>Transformer-1</p> <p>Transformer-2</p> <p>10 wdU GROUNDING ROD</p> <p>evZvm</p> <p>gvwUMetallic Mesh</p> <p>The external metallic frame of the s/g , xformer, substation structure , relay panels and so on are solidly connected to the mesh-metgrounding straps are always are considerable current carrying capacity to provide an easy path for flow of stray current to the ground , the potential though-out the area is at the same ground potential , so providing safety for the personnel working in and around the equipment</p> <p> Uvdigvii jvwWs wK ? Uvdigvii jvwWs nQ DnvK wbivcv mxgvbvq iL DnvK jvWW Kiv | hZ jvW evo ZZ Dnvi Zvcgvv ew cvq | wKmi Zvcgvv ew cvh ? K) Zji L) cvuPvbv Zvii Hot spot ( Winding Hot spot) KZ Zvcgvv Uvdigvii Rb Allowable ? K) Zji - 65 C L) cvuPvbv Zvii Hot spot ( Winding Hot spot) - 80 C wKy GUv eRvi ivLv eo KKi , Kb ? jvwWs me mgq GKB ivLv hvq bv | ZvB Zvcgvv mg~n Kg-ew cvq |</p> <p>wKQy wewea K_v t K) Uvdigvii bgcU Rated Output `Iqv _vK wbw` Zvcgvv Rise Gi Dci hvnv KviLvbvq Kwgfve test Kiv nqwQj| L) UvdigviK (Insulation) wZ bv Ki bgcU Rated Output Gi KvQv KvwQ Output cZ nj mZKfve jvwWs KiZ ne | Ze Rated Output wewfb operating condition Gi Dci wbfI Ki , hgb - evwnii Zvcgvv, cv_wgK Loading , Cooling Provision etc. M) Uvdigvii Avqy Kg hvq hw` Dnv ekxb Overloading Kiv nq| O) KZb Overloading Kiv hve Zvnv wbfi Ki : K) Uvdigvii Byjkbi cKwZ | L) cv_wgK jvwWs | M) Kzwjs</p> <p>Percentage Impedance :Dnv GKwU Uvdigvii dzj jvW Dnv Avf iwRv Ges wjKR wiqvKU Kvib fvR Wc K eySvq | ixb</p> <p>Conditions of Parallel Operation of Transformers :</p> <p>Transformer-1 R Y B R</p> <p>Transformer-2 Y B</p> <p>Transformer-1</p> <p>Transformer -2</p> <p>1) Polarity2) Voltage ratio 3) Percentage impedance 4) Phase Rotation / Sequence 5) Vector Group</p> <p>== = = =</p> <p>Polarityvoltage ratio Percentage impedance Phase Rotation / Sequence Vector Group</p>