Example Report

BEE3133 Electrical Power Systems Distribution System: Radial and Ring Distribution Laboratory 1 Fathimah binti Abdul Halim EA09089 Faculty of Electric and Electrical Engineering Universiti Malaysia Pahang Email: [email  protected] com Introduction Generally, distribution system is part of power systems which distributes power to the consumers for utilization. That distribution system is the electrical system between the sub-station fed by the transmission system and the consumer meters. The distribution systems consist of feeders, distributors and service mains.A feeder is a conductor which connects the sub-station (or localised generating station) to the area where power is to be distributed. Basically no tappings are taken from the feeder so that current in it remains the same throughout. A distributor is a conductor from which tappings are taken for supply to the consumers. The current through a distributor is not constant because tappings are taken at various places along its l ength. A service main is generally a small cable which connects the distributor to the consumer’s terminals. In practice, the radial system and ring main system are used. Experiment 1: Radial Distribution SystemIntroduction Electricity suppliers normally use radial distribution in rural areas where the load is randomly distributed, separated by areas with little or no habitation, and back up supplies are normally not available. The length of feeder is typically limited to 500m or less. In the radial distribution system, feeders supplying the consumers are all fed from a central point (the substation) as shown in Figure 1. There is no looping of the feeders. Figure 1: Radial System of Feeders Objective To demonstrate the principles of the commonly used radial system for low voltage distribution networks. Schematic Diagrams:Figure 2: Schematic diagram for Experiment 1 Procedure A Figure 3: Schematic Diagram for Experiment 1 Procedure B Figure 4: Schematic Diagram for Experiment 1 Procedure C Results for Procedure A: Table 1: Lamp Voltages Load| Voltage| Lamp 1| 23. 0V| Lamp 2| 18. 0V| Lamp 3| 14. 0V| Lamp 4| 11. 0V| Lamp 5| 9. 0V| Lamp 6| 8. 0V| Results for Procedure B: Table 2: Results for Procedure B Circuit Number| Lamp| Feeder| | Measured Voltage| Measured Current| Voltage Drop| 1| 22. 0V| 0. 048A| 6. 0V| 2| 17. 0v| 0. 055A| 12. 0V| 3| 13. 0V| 0. 060A| 15. 0V| 4| 10. 0V| 0. 062A| 18. 0V| 5| 9. 0V| 0. 061A| 20. 0V| 6| 8. 0V| 0. 060A| 21. 0V|Table 3: Calculated and Measured Resistor Currents and Voltages Resistor Number| Calculated Current| Calculated Voltage Drop| Measured Voltage Drop| Error| 1| 0. 846A| 8. 0V| 6. 0V| 25. 00%| 2| 0. 654A| 13. 0V| 12. 0V| 7. 69%| 3| 0. 500A| 17. 0V| 15. 0V| 11. 76%| 4| 0. 385A| 20. 0V| 18. 0V| 10. 00%| 5| 0. 346A| 21. 0V| 20. 0V| 4. 76%| 6| 0. 308A| 22. 0V| 21. 0V| 4. 55%| Table 4: Lamp Voltages Lamp number| Calculated voltage| Measured voltage| Error| 1| 22. 00V| 22. 0V| 0%| 2| 17. 00V| 17. 0V| 0%| 3| 13. 00V| 13. 0V| 0%| 4| 10. 01V| 10. 0V| 0. 10%| 5| 9. 00V| 9. 0V| 0%| 6| 8. 01V| 8. 0V| 0. 12%| Results for Procedure C:Table 5: Separate Feeders CircuitNumber| Lamp| Feeder| | Measured Voltage| Measured Current| Voltage Drop| 1| 28. 0V| 0. 067A| 1. 0V| 2| 26. 0V| 0. 066A| 3. 0V| 3| 25. 0V| 0. 061A| 4. 0V| 4| 24. 0V| 0. 061A| 6. 0V| 5| 22. 0V| 0. 059A| 7. 0V| 6| 21. 0V| 0. 057A| 8. 0V| Discussion: The voltage across each lamp in procedure A, decreased as well as the brightness of the lamps due to the increase in the distance of the lamps from power supply. As the current passes through a longer distance, more the value of voltage is â€Å"lost† (unavailable to the load), due to the voltage drop developed across the resistance of the conductor.In the procedure B, value of current, voltage and voltage drop are calculated and measured. The kirchoff’s Law is used to calculate the value of calculated current. In table 3, the values of calculated and measured voltage for voltage drop are d ifferent from one another since the value of measured voltage drop and calculated voltage drop increased as the distance of the lamps from power supply increased. In table 4, the values of measured and calculated voltage are not much difference from each other.When the distance of the lamps from source increased, both values show a decreased. It can be concluded that as the amount of resistor increases, the voltage drop across the resistor also increases, it is shown in the graph resistor number against voltage drop above. In procedure C, each lamp is fed by a separate feeder connected to the supply. Referring to table 5, when the amount of loads/lamps increase, the voltage across each lamp decreases. However, the voltage drop in each lamp increases corresponding to the amount of loads applied in the procedure.A principle known as Kirchhoff's circuit laws states that in any circuit, the sum of the voltage drops across each component of the circuit is equal to the supply voltage. Con clusion: As conclusion, the principles of the commonly used radial system for low voltage distribution networks is demonstrated. Experiment 2: Ring Distribution System Introduction This is commonly used in urban areas with high housing density. In such system, LV cables from neighbouring distribution substations are either looped together or are terminated very close to one another where an interconnection of cables can be made.This system is normally used when a high degree of reliability of load supply is required and back up substations are made available. Figure 7 shows a schematic diagram for a ring distribution network. Figure 7: Ring Distribution Network Objective To demonstrate the principles of ring distribution systems as used in low voltage networks. Schematic Diagrams: Figure 6: Schematic diagram for Experiment 3 Procedure A Figure 7: Schematic diagram for Experiment 3 Procedure B Results for Procedure A: Lamp Number| Voltage| 1| 26V| 2| 24V| | 22V| 4| 24V| 5| 26V| 6| 30 V| Table 7: Lamp voltages Results for Procedure B: CircuitNumber| Lamp| Feeder| | Measured Voltage| Measured Current| Voltage Drop| 1| 26. 0V| 0. 025A| 4V| 2| 24. 0V| 0. 026A| 6V| 3| 23. 0V| 0. 025A| 7V| 4| 23. 5V| 0. 026A| 6V| 5| 26. 0V| 0. 025A| 4V| 6| 30. 0V| 0. 023A| 0V| Table 8: Voltage and Current Measurements Discussion: The ring circuit acts like two radial circuits proceeding in opposite directions around the ring, the dividing point between them dependent on the distribution of load in the ring.If the load is evenly split across the two directions, the current in each direction is half of the total, allowing the use of wire with half the current-carrying capacity. In procedure A, as the number of load increases, the voltage across lamp increases. The lamp voltage wit the corresponding value obtained in the experiment showed that as the number of load increases, the brightness of the lamp increases. There are differences between lamp voltage for ring distribution system and lamp voltage for radial distribution. The lamp voltage for radial distribution and ring distribution increases as the number of load increases.For procedure B, the comparisons can be made between radial and ring distribution systems. A radial system has only one power source. The lamp voltage for radial system decreased as the load/resistance increased while the lamp voltage for ring system increased as the load/resistance increased. Ring system is more expensive to install as it takes double the cable (but not double the installation time) but it is far superior in performance, as the current to any one socket/outlet has 2 parallel paths to take, so the cable is under less load.Also if one leg of the ring fails open (loose terminal in a socket/outlet) then the remaining leg still safely provides current. Radial circuits are adequate for lighting, as it is a low load, but sockets/outlets are best fed from a ring system. Hence, it can be concluded that ring distribution system offer ed a higher voltage load and lower feeder voltage drop. Conclusion: The objective was achieved. The principles of ring distribution systems as used in low voltage networks is demonstrated. Example Report BEE3133 Electrical Power Systems Distribution System: Radial and Ring Distribution Laboratory 1 Fathimah binti Abdul Halim EA09089 Faculty of Electric and Electrical Engineering Universiti Malaysia Pahang Email: [email  protected] com Introduction Generally, distribution system is part of power systems which distributes power to the consumers for utilization. That distribution system is the electrical system between the sub-station fed by the transmission system and the consumer meters. The distribution systems consist of feeders, distributors and service mains.A feeder is a conductor which connects the sub-station (or localised generating station) to the area where power is to be distributed. Basically no tappings are taken from the feeder so that current in it remains the same throughout. A distributor is a conductor from which tappings are taken for supply to the consumers. The current through a distributor is not constant because tappings are taken at various places along its l ength. A service main is generally a small cable which connects the distributor to the consumer’s terminals. In practice, the radial system and ring main system are used. Experiment 1: Radial Distribution SystemIntroduction Electricity suppliers normally use radial distribution in rural areas where the load is randomly distributed, separated by areas with little or no habitation, and back up supplies are normally not available. The length of feeder is typically limited to 500m or less. In the radial distribution system, feeders supplying the consumers are all fed from a central point (the substation) as shown in Figure 1. There is no looping of the feeders. Figure 1: Radial System of Feeders Objective To demonstrate the principles of the commonly used radial system for low voltage distribution networks. Schematic Diagrams:Figure 2: Schematic diagram for Experiment 1 Procedure A Figure 3: Schematic Diagram for Experiment 1 Procedure B Figure 4: Schematic Diagram for Experiment 1 Procedure C Results for Procedure A: Table 1: Lamp Voltages Load| Voltage| Lamp 1| 23. 0V| Lamp 2| 18. 0V| Lamp 3| 14. 0V| Lamp 4| 11. 0V| Lamp 5| 9. 0V| Lamp 6| 8. 0V| Results for Procedure B: Table 2: Results for Procedure B Circuit Number| Lamp| Feeder| | Measured Voltage| Measured Current| Voltage Drop| 1| 22. 0V| 0. 048A| 6. 0V| 2| 17. 0v| 0. 055A| 12. 0V| 3| 13. 0V| 0. 060A| 15. 0V| 4| 10. 0V| 0. 062A| 18. 0V| 5| 9. 0V| 0. 061A| 20. 0V| 6| 8. 0V| 0. 060A| 21. 0V|Table 3: Calculated and Measured Resistor Currents and Voltages Resistor Number| Calculated Current| Calculated Voltage Drop| Measured Voltage Drop| Error| 1| 0. 846A| 8. 0V| 6. 0V| 25. 00%| 2| 0. 654A| 13. 0V| 12. 0V| 7. 69%| 3| 0. 500A| 17. 0V| 15. 0V| 11. 76%| 4| 0. 385A| 20. 0V| 18. 0V| 10. 00%| 5| 0. 346A| 21. 0V| 20. 0V| 4. 76%| 6| 0. 308A| 22. 0V| 21. 0V| 4. 55%| Table 4: Lamp Voltages Lamp number| Calculated voltage| Measured voltage| Error| 1| 22. 00V| 22. 0V| 0%| 2| 17. 00V| 17. 0V| 0%| 3| 13. 00V| 13. 0V| 0%| 4| 10. 01V| 10. 0V| 0. 10%| 5| 9. 00V| 9. 0V| 0%| 6| 8. 01V| 8. 0V| 0. 12%| Results for Procedure C:Table 5: Separate Feeders CircuitNumber| Lamp| Feeder| | Measured Voltage| Measured Current| Voltage Drop| 1| 28. 0V| 0. 067A| 1. 0V| 2| 26. 0V| 0. 066A| 3. 0V| 3| 25. 0V| 0. 061A| 4. 0V| 4| 24. 0V| 0. 061A| 6. 0V| 5| 22. 0V| 0. 059A| 7. 0V| 6| 21. 0V| 0. 057A| 8. 0V| Discussion: The voltage across each lamp in procedure A, decreased as well as the brightness of the lamps due to the increase in the distance of the lamps from power supply. As the current passes through a longer distance, more the value of voltage is â€Å"lost† (unavailable to the load), due to the voltage drop developed across the resistance of the conductor.In the procedure B, value of current, voltage and voltage drop are calculated and measured. The kirchoff’s Law is used to calculate the value of calculated current. In table 3, the values of calculated and measured voltage for voltage drop are d ifferent from one another since the value of measured voltage drop and calculated voltage drop increased as the distance of the lamps from power supply increased. In table 4, the values of measured and calculated voltage are not much difference from each other.When the distance of the lamps from source increased, both values show a decreased. It can be concluded that as the amount of resistor increases, the voltage drop across the resistor also increases, it is shown in the graph resistor number against voltage drop above. In procedure C, each lamp is fed by a separate feeder connected to the supply. Referring to table 5, when the amount of loads/lamps increase, the voltage across each lamp decreases. However, the voltage drop in each lamp increases corresponding to the amount of loads applied in the procedure.A principle known as Kirchhoff's circuit laws states that in any circuit, the sum of the voltage drops across each component of the circuit is equal to the supply voltage. Con clusion: As conclusion, the principles of the commonly used radial system for low voltage distribution networks is demonstrated. Experiment 2: Ring Distribution System Introduction This is commonly used in urban areas with high housing density. In such system, LV cables from neighbouring distribution substations are either looped together or are terminated very close to one another where an interconnection of cables can be made.This system is normally used when a high degree of reliability of load supply is required and back up substations are made available. Figure 7 shows a schematic diagram for a ring distribution network. Figure 7: Ring Distribution Network Objective To demonstrate the principles of ring distribution systems as used in low voltage networks. Schematic Diagrams: Figure 6: Schematic diagram for Experiment 3 Procedure A Figure 7: Schematic diagram for Experiment 3 Procedure B Results for Procedure A: Lamp Number| Voltage| 1| 26V| 2| 24V| | 22V| 4| 24V| 5| 26V| 6| 30 V| Table 7: Lamp voltages Results for Procedure B: CircuitNumber| Lamp| Feeder| | Measured Voltage| Measured Current| Voltage Drop| 1| 26. 0V| 0. 025A| 4V| 2| 24. 0V| 0. 026A| 6V| 3| 23. 0V| 0. 025A| 7V| 4| 23. 5V| 0. 026A| 6V| 5| 26. 0V| 0. 025A| 4V| 6| 30. 0V| 0. 023A| 0V| Table 8: Voltage and Current Measurements Discussion: The ring circuit acts like two radial circuits proceeding in opposite directions around the ring, the dividing point between them dependent on the distribution of load in the ring.If the load is evenly split across the two directions, the current in each direction is half of the total, allowing the use of wire with half the current-carrying capacity. In procedure A, as the number of load increases, the voltage across lamp increases. The lamp voltage wit the corresponding value obtained in the experiment showed that as the number of load increases, the brightness of the lamp increases. There are differences between lamp voltage for ring distribution system and lamp voltage for radial distribution. The lamp voltage for radial distribution and ring distribution increases as the number of load increases.For procedure B, the comparisons can be made between radial and ring distribution systems. A radial system has only one power source. The lamp voltage for radial system decreased as the load/resistance increased while the lamp voltage for ring system increased as the load/resistance increased. Ring system is more expensive to install as it takes double the cable (but not double the installation time) but it is far superior in performance, as the current to any one socket/outlet has 2 parallel paths to take, so the cable is under less load.Also if one leg of the ring fails open (loose terminal in a socket/outlet) then the remaining leg still safely provides current. Radial circuits are adequate for lighting, as it is a low load, but sockets/outlets are best fed from a ring system. Hence, it can be concluded that ring distribution system offer ed a higher voltage load and lower feeder voltage drop. Conclusion: The objective was achieved. The principles of ring distribution systems as used in low voltage networks is demonstrated.