EHV AC/DC Transmission

1. a) What are the advantages of series compensation in EHV system? What are the problems associated with its use? [8]

b) Explain the corona Phenomenon and factor influencing the corona losses. [8]

1. a) Explain the geometric mean radius of bundle conductor and also derive the necessary formula for it. [8]

b) Explain the percent power loss and power handling capacity. [8]

2. a) Describe the speed governing system to control the real power flow with the help of neat diagram. [8]

b) Two generator rated 250Mw and 400Mw are operating in parallel. The drop characteristics of the governs are 4% and 6% respectively. How would a load of 650Mw be shared between them? What will be the system frequency? Assume nominal system frequency is 60Hz and No governing action. [8]

2. a) Prove that, for a short transmission line the reactive power transferred to receiving end side is proportional to the voltage drop in the line. [8]

b) Explain Automatic generation control with all necessary diagram. [8]

3. a) What are the types of tap changing transformer? Describe their function to control the voltage in Power system. [8]

b) What is shunt compensation? Why it is necessary? Discuss the types of static VAR system. [8]

3. a) Explain the static VAR compensator? Describe (TSC-TCR) with the help of all suitable diagram and mathematical formulas. [8]

b) Explain in detail Synchronous Phase Modifier. [8]

4. a) Explain Unified Power Flow Controller (UPFC) with suitable diagram. [8]

b) Explain in detail the application of FACTS devices. [8]

4. a) Describe Static Synchronous Compensator (STATCOM). [8]

b) Explain the benefits of utilizing FACTS devices in detail. [8]

5. a) What are the main advantages and disadvantages of HVDC transmission system? [8]

b) Explain the principle of DC link control and converter control characteristics. [8]

5. a) What is ground return? Why is it used? What are the problems associated with the use of ground as the return conductor? [8]

b) Explain in detail MULTI-TERMINAL HVDC system in detail. [8]