lecture1_Power System Analysis _USN.pptx

Power system analysis basic

1. Power system analysis I:  general introduction

2. Evolution of power system Power System History:The first power network in the US The first electric network in US was established by Thomas Edison in 1882 The power was generated by DC generators and distributed by underground cables Because of high power loss, the energy could only be delivered to short distances  from the power station, I.e high loss and short range of delivery are the drawbacks of DC system

3. Evolution of power system  Contd... The first AC power network in the US  Transformer was invented in 1885 by William Stanley, which was able to change the voltage level Induction motor was established in 1888 by Nikola Tesla, which replaced DC motor and produced power via AC With ability to control the voltage level, power delivery to longer distance became more efficient as compared to DC First single phase ac in the US was generated by two 300hp waterwheel turbines at 4KV First 3 phase AC was generated at 2.3 KV in 1893

4. Evolution of  POWER SYSTEM contd......

5. Power system Network

6. Interconnection     WHY INTERCONNECTION? Provide higher electric supply with reliability Reduce the reserved margin required for the system  Reduction in frequency fluctuation.

7. Three Levels of power system 

8. THREE LEVELS OF POWER SYSTEM  Contd....... Primary distribution:  The distribution line coming out from area substation is prmary distribution. Primary distribution feeds industrial consumers, commercial consumers, large office buildings, etc. Voltage levels: 11kV, 22kV and 33kV Secondary substation: This is the lowest operation voltage level which supplies electricity to the residenial consumers, small office building, street lightning. The main aimof secondary distribution voltage is safety level to the end users. Secondary distribution can be single phase two wire for small consumers and 3ɸ 4 wire for large consumers. 110 to 130 V and 220 to 260 V for 60 Hz 220 to 240V and 380 to 450 V for 50 Hz

9. Concept of infinite bus In an interconnected system there are large number of electrical generator connected in parallel through transmission line. These generators are of different capacity. If the capacity of individual generator with regard to rest of the system is very small then, the rest of the system is termed as infinite bus.  If the figure bus with voltage level E b is infinite bus. The voltage and frequency of an infinite bus bus remains unaffected by any change in power output of an individual system. For the system of 5000MW, the bus at which generator of 100MW is connected can be termed as infinite bus.