Optimal Distributed Generation Placement Considering Voltage Profile Improvement and Loss Reduction: Case Study on Iranian Distribution Network STSD 2014   S. Hadavi B. Zaker G. B. Gharehpetian N. Ghasemkhani Electrical Engineering Department, Amirkabir University of Technology, Tehran, Iran

National Grand Project of Iranian Smart Grid 1. Introduction The Iranian government has invested in researches about smart grids. One of these projects is: National Grand Project of Iranian Smart Grid In this project, one of the active partners is Amirkabir University of Technology (AUT). STSD 2014   2

What is a Smart Grid? STSD Smart grid generally refers to a class of technology, people are using to bring utility electricity delivery systems into the 21st century, using computer-based remote control and automation. These systems are made possible by two-way communication technology and computer processing that has been used for decades in other industries. They are beginning to be used on electricity networks, from the power plants to the consumers in homes and businesses. STSD 2014   3

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In distribution level and customer side, microgrids are one of the most important subsets of the smart grid. The heart of a microgrid is its DGs. STSD 2014   5

What is a DG? Generation methods can be classified into 2 methods, as shown here: STSD 2014   6

Danish Power System 7

Iran has various climate conditions and different energy resources, therefore diverse technologies of DGs can be used in Iran. Also, Iranian distribution network suffers from poor voltage profile and considerable power losses in some regions. STSD 2014   8

STSD This paper focuses on placement of DGs. Why DG placement? To increase the system performance and reliability. reduce the operational cost and network losses and increase the quality of the power supply. STSD 2014   9

2. Iranian Power System STSD Iranian power system installed capacity is about 70000 MW (14-th in the world ranking). The peak load in this summer (July 26, 2014) was 48527 MW (with 95 MW reserve generation!!!) In the same time, in Tehran Regional Electrical Company (TREC), the peak load was 8600 MW. STSD 2014   10

Generation of Power Plants in Iran Type/Year 2008 2009 2010 2011 2012 Steam (MW) 14565.6 14576.1 14559.9 14567.9 Diesel (MW) 285.4 288.9 278.7 261.8 283.8 Gas (MW) 9807 8447.1 9958.6 9808.7 9908.7 Combined Cycle (MW) 9908.8 11494.8 11697.8 12165.8 12595.8 Water (MW) 7323.8 7356.1 8487.8 8746.2 9746.1 Atomic (MW) - 915 Wind (MW) 89.8 90.6 92.9 98.2 106.1 Solar (MW) 0.073 0.097 0.069 Biogas (MW) 1.7 6.5 STSD 2014   11

The Energy Ministry should add 4000-5000 MW/year, to meet the load. In order to meet the load and overcome the problem of the lack of state financial resources, TREC needs private sector DGs for a generation, near to its 30% of capacity. This means 4000MW in 10 years. Now, TREC has signed contacts with the private sector for 729MW DG installation. STSD 2014   12

STSD Iran has potential of using different kinds of DG technologies. For example: Meshkinshahr city has the chance of using 55MW geothermal energy power plant, Shiraz 250kW photovoltaic, Kahak-Qazvin 7.5MW wind turbine (planed for 200MW as a wind farm) and so on. STSD 2014   13

STSD Why are DGs useful for Iranian network? 1- the load growth has a high rate. This figure shows the forecasted peak load of Iran (in a summer day). STSD 2014   The difference between forecasted and occurred peaks in 2014 is considerable in this figure. 48527MW, this year real peak 14

STSD Why are DGs useful for Iranian network? 1- High rate of load growth. 2-Lack of financial resources for Energy Ministry 3-High dependency on fossil fuel based power plants. 4-Environmental pollution problems in major cities of Iran STSD 2014   15

3. DG Allocation For DG allocation, optimization methods should be used. In this paper, GA, PSO, HSA and analytical approaches have been used to determine the optimal location of different types of DGs. The forward-backward sweep method has been used for load flow calculations. STSD 2014   16

losses reduction and voltage profile improvement have been considered by the following equation as the objective function. STSD 2014   17

The DG location and DG power factor are parameters of the optimization. f(x) is the objective function, where x is a 6 dimensional vector, as follows: x(1), x(2) and x(3) are locations of DGs and x(4), x(5) and x(6) are their power factors, respectively. STSD 2014   18

4. Case Study Kerman state, Chah-Hassan radial distribution network has high power losses and poor voltage profile because of supplying outland villages and feeding lots of agriculture water pumps. This system consists of 681 lines and 682 buses. Kerman state has a very good potential of using different technologies of DGs such as solar, wind and geothermal energy. STSD 2014   19

The mentioned optimization methods have been applied to Chah-Hassan distribution network . It is assumed that 3 DGs with the size of 500kVA should be installed in this network. STSD 2014   20

DG Location (Power factor) 5. Simulation Results   DG Location (Power factor) Losses (kW) VPI ( pu) Objective Function Without DG - 243.09 3.1684 2 GA Bus No. 427 (0.91) Bus No. 353 (0.91) Bus No. 465 (0.89) 76.82 0.1124 0.3515 HSA Bus No. 541 (0.92) Bus No. 565 (0.94) Bus No. 535 (0.83) 78.46 0.1094 0.3573 PSO Bus No. 353 (0.95) Bus No. 427 (0.88) 76.96 0.1133 0.3524 STSD 2014   21

STSD This figure shows that DGs installation is useful for voltage profile improvement in this network. STSD 2014   22

5. Conclusion In Iranian power system, DGs should be widely used because of Energy Ministry policies, pollution produced by fossil fuels based power plants, lack of financial resources of Energy Ministry and the load growth high rate. The optimal allocation of DGs has an important effect on voltage profile and loss reduction and also reliability. STSD 2014   23

In this paper, optimal DGs allocation has been effectively determined in Kerman state, Chah-Hassan radial distribution network, as a case study. STSD 2014   24

Thank you for your attention. STSD 2014   grptian@aut.ac.ir