Understanding HT Transmission Conductors: ACSR and More

🔥 Ferroresonance: The Silent Killer of MV Switchgear VTs 🔥 Did you know that a mysterious phenomenon called ferroresonance can destroy your medium voltage voltage transformers (VTs) in seconds? What is Ferroresonance? It's a nonlinear resonance occurring when VT magnetizing inductance interacts with system capacitance during: •Switching operations 🌀 •Single-phase interruptions ⚡ •Fault conditions 🔧 This creates sustained overvoltages(up to 5× normal!) and chaotic currents . The Damage: •Thermal: Windings overheat from excessive currents •Dielectric: Insulation breakdown from sustained overvoltages • Mechanical: Core damage from magnetostrictive forces •Harmonic distortion: Distorted waveforms disrupt protections Protection Solutions: 1. Damping resistors in open-delta secondaries (traditional but inefficient). 2. Electronic dampers - activate only during resonance 3. VT design optimization - lower flux density operation (0.4-0.7 T) 4. System design - avoid dangerous configurations/capacitance values Have you encountered ferroresonance incidents? Share your experiences below! #Ferroresonance #VoltageTransformers #Switchgear #PowerSystems #ElectricalEngineering #ProtectionRelay #MediumVoltage #VTProtection

List of Transformers Tests: 1. Winding Resistance Test 2.IR and PI Test 3. Ratio Test 4. Vector Group Test 5. Magnetic Balance Test 6. Core Insulation Test 7. Sweep Frequency Response Analysis 8. Dielectric Frequency Response Analysis 9. Oil Testing: 10. Tan Delta / Power Factor Test (Winding and Bushing) 11.Thermal lmaging (to check hotspots post-loading) 12. Impulse Test (if applicable) 13. Cooling System Functional Test 14. OLTC Operation Test 15. Dynamic Contact Resistance Measurement (DCRM) 16. Motor Current Analysis 17.Tap-to-Tap Transition Timing 18. Partial Discharge Test 19. Induced Overvoltage Test 20. Noise Level Measurement 21.Earth Resistance Test List of LV & MV Cable Tests: 1. Visual Inspection 2. Insulation Resistance (IR) Test 3. Phase Sequence and Continuity Test 4. High Voltage Test (VLF or DC Withstand Test) 5. Sheath Continuity and Insulation Test 6. Tan Delta (Dissipation Factor) Test 7. Partial Discharge (PD) Test 8. Earth Continuity Test 9. Cable Routing and Installation Check 10. Length Test 11. Earth Resistance Test 12.Thermography (Infrared Scanning)

👉What is the maximum earth loop impedance allowed in an electrical installation? 🫴It depends on the protective device used. For example, for a 230V,30A circuit protected by a Type B MCB, the maximum earth loop impedance is about 1.44 ohms (calculated to ensure disconnection within 0.4 seconds). Always refer to SS 638 tables for exact values.

132kV Circuit Breaker Explained: The Silent Guardian of the Grid When a fault strikes in a high-voltage system, the response has to be instant — and that’s where the 132kV Circuit Breaker comes in. Often mistaken as just a “big switch,” this piece of equipment is actually the first line of defense for the entire grid. In just a fraction of a second, it interrupts massive fault currents, prevents damage to transformers and lines, and most importantly, protects the safety of people working around the system. In this video, we’ll explore how a 132kV Circuit Breaker really works, why it’s considered one of the most critical devices inside a PMU, and the hidden engineering behind its ability to stop faults in milliseconds. By the end, you’ll see the circuit breaker not as a simple switch — but as a silent guardian that keeps the power system running safely and reliably. Others Video related to 132kV System : 132kV Single Line Drawing and how to draw it: https://lnkd.in/grzBxqH3 132kV Numbering for Equipment and how to recognised it : https://lnkd.in/gtST9RCM 132kV Common Primary Equipment : https://lnkd.in/gjrCNZaE 132kV Side View: https://lnkd.in/gciSbDMM 132kv AIS Vs GIS Substation: https://lnkd.in/gtad7ZaU Different Between AIS & GIS Substation : https://lnkd.in/g3WsBVEK Surge Arrestor and its Function : https://lnkd.in/g8UecrJS Capacitive Voltage Transformer (CVT) and its function : https://lnkd.in/gWhm2y56 Line isolator function : https://lnkd.in/gHbzXngA Current Transformer https://lnkd.in/gUXSkGDP 132kv Circuit Breaker : https://lnkd.in/g8Tu4w5t Want to join my Class about 132kV System? : https://lnkd.in/grFNwj-z

Internal Structure & Connections of 3-Phase Transformer The image above shows the internal structure of a 3-phase transformer along with its two main winding connections: Star (Y) and Delta (Δ). 3-Phase Transformer Structure: It consists of three sets of primary and secondary windings mounted on a laminated magnetic core. Used in power transmission and distribution to step up or step down voltage levels efficiently. Ensures balanced load sharing in industrial and utility power systems. Star (Y) Connection: One end of each phase winding is connected to a common neutral point, forming a "Y" shape. Line Voltage = √3 x Phase Voltage Provides neutral point loads. useful for single-phase Applications: Long-distance transmission, distribution systems, where neutral grounding is required. ▲ Delta (A) Connection: The end of each phase winding is connected to the start of the next, forming a closed loop (triangle). Line Voltage = Phase Voltage No neutral available, suitable for balanced loads. Applications: Industrial loads, short-distance high-power transmission, and motor starting.

The internal and external parts of an oil-immersed power transformer. 1. Conservator Tank A cylindrical tank mounted on top of the transformer. It stores extra insulating oil and accommodates oil expansion/contraction due to temperature changes. 2. Buchholz Relay A protective relay installed between the main tank and conservator. Detects gas accumulation or sudden oil movement (caused by internal faults) and triggers an alarm or trips the transformer. 3. Bushings Insulated devices through which the transformer connections (HV & LV terminals) pass. They safely allow electrical conductors to pass through the transformer tank without leakage or short-circuiting. 4. Oil Level Indicator Shows the oil level inside the transformer tank or conservator. Helps operators ensure there’s sufficient insulating/cooling oil. 5. Pressure Relief Valve Safety device that releases excess pressure from the tank during faults or overheating. Prevents transformer explosion. 6. Cooling Tubes (Radiators) Attached outside the main tank. Increase the surface area for heat dissipation. Oil circulates through them (natural or forced circulation) to cool the transformer. 7. Tap Changer Changes the number of turns in the transformer winding. Adjusts output voltage to keep it stable despite input or load variations. Can be On-Load Tap Changer (OLTC) or Off-Load Tap Changer. 8. Core Made of laminated silicon steel sheets. Provides a path for magnetic flux and reduces eddy current & hysteresis losses. 9. Primary Winding The coil connected to the input supply (HV or LV side depending on step-up/step-down use). Creates magnetic flux in the core when AC flows through it. 10. Secondary Winding The coil connected to the load side. Induced EMF appears here due to mutual induction. Provides the required stepped-up or stepped-down voltage. 11. Main Tank Houses the core, windings, and insulating oil. Provides mechanical protection and electrical insulation. 12. Insulating Oil (not directly labeled but shown in the tank) Immerses the windings and core. Functions: insulation, cooling, and arc suppression.

What is a Busbar? A flat strip of copper or aluminum used to distribute large currents within electrical systems like panels, switchgear, or substations. Key Factors in Sizing: ✅Current carrying capacity (determined by width, thickness, material), ✅ temperature rise, ✅short-circuit withstand, and ✅voltage drop. Current Capacity Formula For Busbar: ✍️The current (I) a busbar can carry is calculated by ✅multiplying its cross-sectional area (A) in mm² by ✅a current density constant (k) specific to the material (((1.2 to 2.0) A/mm² for copper),( 0.8 to 1.4) A/mm² for aluminum). ✍️Material Constant for Fault Current Calculation: For calculations involving short-circuit duration and thermal stress, the material constant k is crucial. Formula: A = √(I² x t) / k A = Cross-sectional area (mm²) I = Fault current (A) t = Fault duration (seconds) k = Material constant Values of K (per IEC 60949) Copper: k ≈ 205 Aluminum: k ≈ 126

Smart Technical Generator Calculation Formulas? RPM: (120 *F) / Number of Poles KVA: (Amps x Volts x 1.732) % 1000 KVA from KW: KVA: KW% Power Factor Generator Rotor Current(I2) : S E2 % (R2^2) x 1.732 + (Sx2) ^2 Rotor Current in a synchronous generator is the field current (If) : Vf / Rf OR (If): Px / Vf Px is a excitation Stator Current Formula (I) : (1000 X S) / V x 1.732 Stator current formula samely appliances of Bushing Current. Armature Copper Loss: Ia^2Ra Shunt Field Copper Loss: Ish^2Rsh Series Field Copper loss: Ise^2Rse Total Copper loss : Ia^2Ra + Ish^2Rsh + Ise^2Rse Generator Torque : T(N-m) : (60 + P(W)) / 6.283 + N(RPM)) For a shunt Generator(Ia) : IL + Ish Induced emf Eg: V + IA RA For a shunt generator total Voltage (Vt) : Eg - IA RA Generator Dynamic load or Bearing (P) : X Fr + Y Fa

🔹 Main Components in the Panel: 1. Incoming Supply (Bottom part) The thick red, yellow, blue, and black wires at the bottom are the 3-phase + Neutral incoming supply from the main source (transformer or main meter). These are connected to the Main MCCB/Isolator (bottom breaker). It is the master switch that controls the entire panel. 2. Busbars & Cabling After the main breaker, power is distributed to horizontal busbars (inside the panel, behind breakers). From busbars, red wires (Phase lines) are connected to different rows of breakers. Black wires on the side are the outgoing loads (to lights, sockets, equipment). 3. RCCB/RCB (2P/4P switches with test button) Each row starts with a big breaker (with a "test" button) – these are RCCBs (Residual Current Circuit Breakers). They provide earth leakage protection (protect people from electric shock). 4. MCBs (Miniature Circuit Breakers) The smaller switches next to RCCBs are MCBs. Each MCB controls a specific circuit (e.g., lighting, AC, sockets, geyser). They protect from overload & short circuit. 5. Neutral & Earth Links (Right side) The green/yellow terminals on the right side are Earth terminals. Neutral wires are also grouped and connected properly.

Transformer winding is a crucial process that directly affects the performance and efficiency of the entire device. High-quality copper or aluminum wire is precisely wound onto the core to form primary and secondary coils, ensuring excellent electrical conductivity and stable magnetic flux. During the winding process, strict tension control and insulation layering are applied to prevent short circuits and improve durability. Proper winding not only reduces energy loss, but also enhances the reliability of transformers in long-term operation. #TransformerWinding #PowerTransformer #HighEfficiency #CopperWinding #StablePerformance #ElectricalEngineering #ReliablePower #EnergyInfrastructure #PrecisionManufacturing