Complete Electrical Machines course for B.Tech EEE and GATE in 80+ video lectures: magnetic circuits, DC machines, single-phase and three-phase transformers, induction motors, alternators and synchronous motors. Watch in order: each lecture builds on the previous one. Modules: 1. Magnetic Circuits & Electromagnetic Induction (Lectures 1A-1R) 2. DC Machines: construction, windings, EMF equation, armature reaction, losses (2A-2J) 3. DC Motors: torque, characteristics, speed control (3A-3C) 4. Single-Phase Transformers: EMF equation, equivalent circuit, OC/SC tests, regulation, efficiency (4A-4H) 5. Three-Phase Transformers: winding connections, vector groups, Scott connection (5A-5D) 6. Three-Phase Induction Motors: rotating magnetic field, torque-slip, equivalent circuit, starting (6A-6K) 8. Alternators (Synchronous Generators): EMF equation, armature reaction, voltage regulation, two-reaction theory (8A-8J) 9. Synchronous Motors: starting, effect of excitation, synchronous condenser, applications (9A-9J) 10. Single-Phase Induction Motors: double revolving field, types, equivalent circuit (10A-10E) Solved problems for every module (Electrical Machines Tutorials): https://www.youtube.com/playlist?list=PL5TKV1tzb09kPh9xyaU8yZC4ph305bTty Notes & more: https://engineeringdevotion.com #ElectricalMachines #ElectricalEngineering #GATEEE
Curated by: Engineering Devotion (81 videos)
Synchronous Motor: Load Behavior with Constant & Varying Excitations A synchronous motor is an AC motor that operates at a constant speed, synchronized with the frequency of the supply voltage. Its unique characteristic lies in its ability to operate at leading, lagging, or unity power factor by simply adjusting its DC field excitation. Load with Constant Excitation: When the excitation (field current) is kept constant, a synchronous motor will maintain its synchronous speed even as the mechanical load on its shaft changes. However, increasing the load will cause the rotor to momentarily fall back in phase, leading to an increase in the load angle ($\delta$) and armature current ($I_a$) to draw more power. The power factor will also shift, typically becoming more lagging as the load increases (if initially over-excited). There's a "pull-out torque" beyond which the motor loses synchronism and stops. Load with Different Excitations (Variable Excitation): This is where synchronous motors shine. By varying the DC field excitation while maintaining a constant mechanical load, the motor's power factor can be precisely controlled: Under-excited: The motor operates at a lagging power factor, consuming reactive power from the grid. Armature current is high. Normally excited (Critical Excitation): The motor operates at unity power factor, drawing minimum armature current for a given load. Over-excited: The motor operates at a leading power factor, supplying reactive power to the grid. This makes them valuable for power factor correction in industrial plants. This behavior is often illustrated by V-curves and inverted V-curves, showing the relationship between armature current/power factor and field current for different constant loads. Important Search Queries: synchronous motor power factor correction, synchronous motor V curves, effect of excitation on synchronous motor, synchronous motor load angle, synchronous motor applications, synchronous motor characteristics, leading power factor synchronous motor, lagging power factor synchronous motor, synchronous motor normal excitation, synchronous motor pull-out torque. #SynchronousMotor #PowerFactorCorrection #ElectricalMachines #MotorControl #ExcitationSystem #V_Curves #IndustrialAutomation #ElectricalEngineering #PowerSystems --- Electrical Machines full course (lectures): https://www.youtube.com/playlist?list=PL5TKV1tzb09lbVthPhckKZ7JsnwHkWmFP Electrical Machines solved problems (tutorials): https://www.youtube.com/playlist?list=PL5TKV1tzb09kPh9xyaU8yZC4ph305bTty Notes & more: https://engineeringdevotion.com