Homework 1 Name:
Topic 8 – Substation Design
Distribution System Engineering Course
Instructor: Brian Winoski
Due: May 21 (Eastview)
May 22 (TLC)
Submit via upload to the LMS
Read chapters # 17, 22 & 24 of the standard handbook for electrical engineers, 15th edition – Text Book – Then answer the following questions:
1. The substation design determines the electrical and physical arrangement of the switching equipment. Different bus schemes can be selected as emphasis is shifted between the factors of safety, reliability, economy and simplicity. Breaker and half scheme – Most flexible and high reliability operation. True False
2. The substation design determines the electrical and physical arrangement of the switching equipment. Different bus schemes can be selected as emphasis is shifted between the factors of safety, reliability, economy and simplicity. Double bus, double breaker scheme – Most expensive scheme True False
3. The rigid bus usually requires less land area than the strain bus True False
4. The rigid bus designs are comparatively lower cost than the strain bus True False
5. Buses are rated on the basis of the temperature rise, which can be permitted without danger of overheating equipment terminals, bus connections, and joints True False
6. Rigid – bus materials are aluminum and copper. Copper as the advantage of being one-third the weight of aluminum, less expensive and requires little maintenance. True False
7. Tubular conductors have a better current distribution than any other shape of conductor of similar cross – sectional area. True False
8. Thermal expansion and contraction of bus conductor is insignificant factor in bus design. True False
9. The most severe over voltages are caused by lightning strokes and by switching surges. The main method to prevent these over voltages from causing insulation failure includes the use of circuit breakers and fuses. True False
10. Gas insulated substations – The sulfur hexafluoride (SF6) gas is heavier than air, which causes it to settle in lower areas. True False
11. Most of the protective and control practices for air – insulated substation apply also for gas – insulated substation True False
12. The National Electric Safety Code (C2) divides grounding into two distinct areas, equipment grounding & system grounding. The equipment grounding is the process of connecting above – ground equipment to the earth. The system grounding is the process of intentionally making an electrical connection to the earth. True False
