👤 Candidate: Aniket Thakur
🗓️ Date: 20th June 2025
🎯 Experience Level: Above Average
⏱️ Duration: Approx. 30–40 minutes
📍 Mode: Technical | Conceptual | Application-Oriented
🧩 Core Questions Asked:
🔌 1. Asynchronous Grids & Cascading
- Q: How can two asynchronous electrical grids be cascaded?
- Discussion: Explained principles of HVDC link usage for interconnecting non-synchronous grids and maintaining frequency independence.
⚡ 2. Lightning Protection
- Q: What happens when lightning strikes a building?
- Follow-up: What are the preventive measures?
- Answer Discussion: Talked about lightning arresters, grounding systems, surge protection devices, and earthing standards.
🔋 3. Resistive Networks
- Q: A bundle of resistors is given in a circuit — calculate the equivalent resistance (Req).
- Task: Apply combination rules for series and parallel resistors to simplify the network.
🧠 Control Systems & Machines
🎛️ 4. Practical Applications of Control Systems
- Q: Where are control systems used in a typical room setup?
- Answer Discussion: Explained fan speed control (PID in electronics), temperature regulation (thermostats), automatic lighting (motion sensors), etc.
🔄 5. Types of Controllers
- Q: Name and differentiate between P, PI, PD, and PID controllers.
- Follow-up: Which controller would be ideal in a given practical setup?
⚙️ Electrical Machines – Deep Dive
💨 6. Induction Motor (IM)
- Q: Draw and explain the Torque-Slip Characteristics of an Induction Motor.
- Follow-up: What changes occur under various loading conditions?
📈 7. Inverted V-Curve – Synchronous Motor
- Q: Draw and explain the inverted V-curve of a synchronous motor.
- Concept Tested: Relation between armature current and field excitation.
⚡ 8. Reactive Power Flow – Synchronous Machines
- Q: Between a Synchronous Generator and a Synchronous Motor, which one supplies reactive power and which one absorbs it?
- Application: When both are interconnected in a grid, analyze reactive power flow.
🔁 System Response & Special Cases
📉 9. Underdamped System
- Q: Draw the response graph of an underdamped second-order system.
- Discussion: Damped oscillations, time-domain parameters, and settling time.
🔄 10. Phase Sequence Swap in Induction Motor
- Q: What happens when the RYB phase sequence is changed to RBY in an Induction Motor?
- Answer:
- Direction of rotating magnetic field (RMF) changes
- Result: Reverse rotation of the motor
✅ Summary:
- Experience: Interviewers focused on clarity of concepts, real-world applications, and the ability to interpret diagrams and graphs.
- Key Topics Covered:
- Power systems
- Electrical machines
- Control systems
- Circuit theory
- Signal response
📌 Tips for Future Candidates:
- Be ready to draw and explain graphs (e.g., V-curves, torque-slip, system response).
- Always relate theoretical answers to practical applications (e.g., lightning arresters, control systems at home).
- Understand the physical significance of parameters like slip, flux direction, and excitation.
📞 For more guidance or PSU interview preparation:
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📲 +91 9404109392
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