In electrical power systems, High Voltage Direct Current (HVDC) transmission plays a critical role in long-distance bulk power transfer. It is a frequently asked topic in SSC JE Electrical as well as other JE/AE exams like RRB JE, UPPCL JE, UPPSC AE, etc. Below are the most important multiple-choice questions (MCQs) on HVDC Transmission, including SSC JE previous year questions (PYQs) and practice questions with explanations.
✅ 1. SSC JE 2020 - Q. Which of the following is an advantage of HVDC transmission over HVAC?
- A. Higher transmission losses
- B. Poor voltage regulation
- C. Less corona loss
- D. More reactive power generation
✅ Answer: C. Less corona loss
Explanation: HVDC systems have lower corona and dielectric losses compared to HVAC, especially in long-distance transmission.
✅ 2. SSC JE 2018 - Q. The main advantage of HVDC transmission is:
- A. It requires a larger right of way
- B. It has more transmission losses
- C. It is more economical for long distances
- D. Requires more insulation
✅ Answer: C. It is more economical for long distances
Explanation: HVDC becomes cost-effective and efficient for transmission distances greater than 600 km for overhead lines and 50 km for submarine cables.
✅ 3. SSC JE 2017 - Q. Which component is used to convert AC to DC in HVDC systems?
- A. Inverter
- B. Rectifier
- C. Transformer
- D. Synchronous condenser
✅ Answer: B. Rectifier
Explanation: A rectifier converts AC to DC at the sending end, and an inverter converts DC back to AC at the receiving end in HVDC systems.
🧩 Additional Practice MCQs – HVDC Transmission for JE/AE Exams
✅ 4. RRB JE 2019 - Q. In an HVDC system, which of the following is an essential component?
- A. Capacitor bank
- B. Exciter
- C. Converter station
- D. Ground wire
✅ Answer: C. Converter station
Explanation: HVDC systems use converter stations at both ends — one for rectification and one for inversion.
✅ 5. UPPCL JE 2018 - Q. Which of the following is NOT an advantage of HVDC transmission?
- A. Reduced line losses
- B. Simple line construction
- C. Easier voltage transformation
- D. No reactive power compensation
✅ Answer: C. Easier voltage transformation
Explanation: Voltage transformation is more complex in HVDC systems than HVAC, which uses transformers. HVDC uses converters and smoothing reactors.
✅ 6. UPPSC AE 2021 - Q. What is the typical transmission voltage level used in HVDC systems?
- A. 11 kV
- B. 132 kV
- C. 400 kV
- D. 765 kV
✅ Answer: C. 400 kV
Explanation: Common voltage levels for HVDC are in the range of 100–800 kV. 400 kV is a standard level used for bulk transmission.
📘 Quick Facts About HVDC Transmission
- HVDC is preferred for transmission distances >600 km (overhead) and >50 km (submarine).
- Converter stations are expensive, but overall system cost is lower for long distances.
- HVDC has no skin effect and lower corona losses compared to HVAC.
- Common converter types: Line Commutated Converter (LCC), Voltage Source Converter (VSC).