BEE2133 Electrical Machine & Power System

1. BEE2133 Electrical Machine & Power System Chapter 4 An Overview of Power System Norazila Jaalam

2. Chapter outline • Introduction • Power system components - Generation, transmission, distribution • Power system loads - Types of load, load demand, demand curve • Power system in Malaysia - Energy generation company • - IPP, co-generator • - National Grid System

3. Introduction Support Components Main Components

4. Power System Components • At power generating station (generating voltage)  11 – 20kV and frequency of 50 Hz • Transform to higher voltage (transmission voltage)  132kV, 275kV and 500kV • Transform to lower voltage (distribution voltage)  33kV or 11kV

5. Power System Components Generation Step-up transformer (↑ voltage,↓current) Grid System (500kV, 275kV, 132kV, 66kV) TNB SESCO SESB Reduce the voltage 33kV,11kV Transmission Distribution Loads 3 phase - 415 V, single phase - 240 V

6. Power System Components

7. Power System Components AROUND TOWN & RESIDENTIAL AREA - Underground distribution to individual premises is at 415V and 240 V HOUSE - Overhead distribution to individual houses is at 240V. SMALL INDUSTRY - Most small factories receive their electricity at 11kV HEAVY INDUSTRY - Some have direct connections to the transmission at 132kV POWER STATION- Generator output at 11kV/20kV is stepped up by transformer to 132kV 275kV and 500kV for transmission. TRANSMISSION - Transmission is mainly at 132kV, 275kV and 500kV

9. Power System Components • (Generation) High voltages of 500kV, 275kV, 132kV are used for transmitting electricity over the grid system

10. Power System Components (Generation) • Generation Plant Mix

11. Power System Components (Generation) Combustion Turbine Power Plant

12. Power System Components (Generation) Coal-fired Power Plant-near a river/lake bcoz large quantities of cooling water are needed to condense the steam as it exhaust from the turbines

13. Power System Components (Generation) Hydroelectric Power Plant Sultan Mahmud Power Station, Kenyir

14. Power System Components (Generation) Bakun Dam: Under construction

15. Power System Components (Generation) TNB Power Stations

19. Power System Components (Transmission) A transformer in a large sub-station reduces the voltage to 33kV, 22kV,11kV

20. Power System Components (Transmission) • Lines/transformers operating at voltages above 100 kV are usually called the transmission system. • Consists of Transmission Line and Sub-stations • Transmission network of 500kV, 275kV and 132kV known as National Grid.

21. Power System Components (Transmission) • Transmission Line • Overhead Lines • Cable • Underground Cables • Submarine Cables • Sub-stations

22. Power System Components (Transmission) Transmission Parameters

23. Power System Components (Transmission) Transmission tower Waist-Type Tower Double Circuit Tower Guyed-V-Tower

24. Power System Components (Transmission) Transmission tower

25. Power System Components (Transmission)

26. Power System Components (Transmission) Overhead Line Conductors Overhead Line Conductors

27. Power System Components (Transmission) Sub-station • Size of substation • Depends on transformer size • Typical sizes • 132kV; 2 x 30MVA, 3 x 45MVA, 2 x 90MVA • 275kV; 2 x 180MVA, 3 x 180MVA, 2 x 240MVA • Types of Sub-station • Conventional outdoor • Require bigger space • GIS (gas insulated switchgear) • Less space • Outdoor or indoor

28. Power System Components (Transmission) Outdoor Sub-station

29. Power System Components (Transmission) GIS

30. Power System Components (Transmission) Sub-station Components • Transformer • Circuit Breaker / Switch Gear • Isolator Switches • Busbar • Protection Relay & Control Equipment

31. Power System Components (Transmission) Power Transformer

32. Power System Components (Transmission) Circuit Breaker Spark gap. In event of a lightning strike on the line, the current can jump the gap between that ball and the protrusion on the tank, and make a path to earth. This prevents overloading the breaker.

33. Power System Components (Transmission) Circuit Breaker

34. Power System Components (Transmission) Insulators

35. Power System Components (Distribution) Supplies to rural communities are often reduced from 11kV to domestic voltages (415/240V) by pole mounted transformers.

36. Lines/transformers operating at voltages below 100 kV are usually called the distribution system. Part of the electric utility system between the bulk power source and the customer service entrances (loads).  33kV, 22kV, 11kV, 6.6kV, 415V and 240V Power System Components (Distribution)

37. Distribution Sub-station Distribution Intakes (33kV, 22kV) Distribution Substations (22kV, 11kV, 6.6kV) Indoor substation Outdoor substation Pole mounted substation Compact substation Underground substation Transformer capacity 100kVA, 300kVA, 500kVA, 750kVA and 1000kVA Power System Components (Distribution)

38. Distribution Intake Power System Components (Distribution)

39. Indoor Sub-station Power System Components (Distribution)

40. Underground Sub-station Power System Components (Distribution)

41. Compact Sub-station Power System Components (Distribution)

42. Outdoor Sub-station Power System Components (Distribution)

43. Pole-Mounted Sub-station Power System Components (Distribution)

44. Types of Load: Residential Commercial Industrial Public Transportation Public Lighting etc. Power System Loads

45. Residential Load Consist of lighting, radio, TV, refrigerator, kitchen appliances, washing machine and etc. Usually, increases in the evening around 6 p.m. and return to a nominal value around 12 p.m.   Power System Loads Commercial Load • Consists of lighting, air-condition and small appliances. • Shops, business premises, schools, universities etc. • The load is fairly constant from 9am until 9pm with the exception of any mid-day break.

46. Industrial Load Mainly consists of motor load, air conditioner, lighting, welding and furnaces etc. It can be divided into small, medium and large category. The nature of industrial load curve depends on the number of shifts worked in the industry. Power System Loads

47. Electricity Consumers

48. Power System Loads • Electricity energy cannot be stored. • Generate electricity based on demand. • Total power drawn by consumer fluctuates depends on the time of day and seasons. • Demand Curve • Plot each demand of electricity by consumer daily/annually

49. Demand Curve Power System Loads

50. Load Duration Curve Power System Loads • 3 types of load • Base load • Has to be fed 100% of the time. • Intermediate loads • Have to be fed <100% of the time. • Peak load • May occur 0.1% of the time.