EEET 4074

EEET 4074 - Operation and Control of Modern Power Systems

Assignment

National Electricity Market and Power Flow Analysis

The objectives of this assignment are:

 To familiarise with National Electricity Market of Singapore

 To investigate power flow analysis of a general power system This is a group assignment and two students will work in a group. Each group is required to submit a single formal report. Part-A (National Electricity Market of Singapore)

Download monthly electricity data from National Electricity Market of Singapore (NEMS) website https://www.emcsg.com/marketdata/priceinformation (Uniform Singapore Energy Price and Demand Forecast). Merge the downloaded data to a single file to represent electricity data for a complete financial year (January-December). Process the data (in MATLAB or Excel) to obtain the following:

1. Yearly load variation and price variation curves

2. Yearly load duration curve including its interpretation

3. Annual energy trade (MWh and dollars) and the average cost of energy ($/MWh)

4. Load variation of a typical week and a typical month.

Part-B (Power Flow Analysis)

The single line diagram of the IEEE 14-bus system is shown in the following page [a]. The power flow data of the system is also given in the following page.

1. Obtain base-case power flow solution using Newton-Raphson (NR) method and show the voltage profile of the system.

2. Using the power flow results (voltage magnitudes and angles) and line data,

calculate the complex power generated by the swing generator. Also determine the complex power at both ends of tap changing transformer connected between buses 5 and 6. Compare the calculated results with the corresponding simulation results obtained in part 1 and find the errors in percentage.

3. The reactive power of a voltage-controlled bus (or a P-V bus) depends on the

specified voltage magnitude of the bus. Vary the voltage magnitude of P-V bus 2 from 0.90 pu to 1.10 pu (with a suitable increment). You may relax the reactive power limits of the bus (say, from -500 to +500 MVAr), if necessary. Run the power flow program and record the corresponding reactive power of the generation. Plot the variation of reactive power against terminal voltage of the generator.

4. The voltage magnitude of a load bus (or a P-Q bus) depends on load of the bus.

Select a particular load bus and increase the load of the bus at a constant power factor (0.8 lagging) in step (start at 10 MVA) and obtain the corresponding voltage from power flow solutions. Continue to increase the load until the voltage drops to 0.8 pu. Plot the load voltage against load MVA of the bus. Describe a common method of improving voltage of a load bus with suitable simulation results.

5. Consider the system load is decreased by 50% during off-peak period and increased

by 75% during peak period. Investigate the voltage profile of the system during peak and off-peak periods.

Report

The deliverables of the assignment are the results of steps 1-4 of Part-A, and steps 1-5 of Part-B. You need to provide summary of the results with critical analysis and discussions. The assumptions and approximations used in evaluating the results should also be clearly stated. The reports should have the following format: title, short abstract, brief introduction, main body (with sections and sub-sections as required), conclusions and references. The report should be submitted via learnonline as a single pdf file.

References

[a] L. L. freris and A. M. Sasson, “Investigation of the Load Flow Problem”, Proc. IEE, Vol. 115, pp.1459-1479, 1968.

EEET 4074 / M. H. Haque / 2014