Small-scale Solar Plants coupled with Smart Public Transport System and its Coordination
1. Failures from hardware side: Four types of failures have been considered under this category
3.3 Results and discussion
3.3.1 Case-1: SPTS performance for normal and special days
ONB impact on the performance of both, the grid and SPTS for ND and SDs are shown from Fig. 3.13 to 3.24. The improvement in Vpu profile of the grid and the energy behaviour of ESD and SP during both, the off-peak and peak periods have been explained through these results.
For ND: Vpu response of the grid for ND is given in Fig. 3.13. ESD is receiving energy from both the grid and SP during off-peak period. ESD is sending its stored energy back to the grid along with SP during peak period. The area between the actual and resultant Vpu curves show that the valley filling/peak shaving in off-peak/peak period. Mostly the Vpu
profile has stayed under off-peak period during sunshine hours, so that the SP is sending its total energy to ESD as shown in Fig. 3.13.
Fig. 3.13 Vpu profile of the grid for ND
The energy behaviour of ESD and SP for ND is shown in Fig. 3.14. The positive/negative values of ESD curve represents the amount of energy received/sent by ESD from/to the grid.
The positive/negative values of SP curve represents the amount of energy sent to ESD/to the grid. The Vpu profile has remained under off-peak period from 10:00 to 24:00 h and 04:00 to 06:00 h so that ESD is receiving energy from the grid. Also, SP is sending its total energy to ESD from 10:00 to 17:00 h. In this duration ESD is receiving energy in two directions: one is from the grid and the other is from SP. The Vpu profile has remained under peak period from 24:00 to 03:00 h and from 06:00 to 10:00 h. ESD is sending its stored energy back to the gird during this period. Also, SP is sending energy to the grid from 06:00 to 10:00 h and that can be observed from Fig. 3.14. The e-buses receive energy from ESD for 24 h with respect to ONB (ref. (3.5)). SP energy generation is proportional to solar irradiance availability for ND and SDs (ref. Fig. 3.4).
Fig. 3.14 The energy behaviour of ESD and SP for ND
For SDs: Vpu profile for SD1 is shown in Fig. 3.15. ESD is receiving/sending more/less energy from/to the grid during off-peak/peak period. Improvement in the Vpu profile of the
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Vpu
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Vpu actual Vpu resultant
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Energy (kWh)
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ESD SP ESD to e-bus
grid during off-peak and peak period (using the energy support from both, ESD and SP to the grid) can be observed from Fig. 3.15.
Fig. 3.15 Vpu profile of the grid for SD1
The energy behaviour of ESD and SP for SD1 is shown in Fig. 3.16. The Vpu profile of the grid has stayed under peak period from 20:00 to 03:00 h, from 10:00 to 11:00 h and from 12:00 to 17:00 h, so that ESD is sending energy to the grid during this period. SP sent energy to the grid from 10:00 to 11:00 h and from 12:00 to 17:00 h, as shown in Fig. 3.16. The Vpu profile of the grid has stayed under off-peak period from 17:00 to 20:00 h, from 03:00 to 10:00 h and from 11:00 to 12:00 h, so that ESD is receiving energy from the grid during this period. Also, SP has sent energy to ESD from 08:00 to 10:00 h, from 11:00 to 12:00 h and from 17:00 to 18:00 h, as shown in Fig. 3.16. After 20:00 h, the energy status of ESD is reached to its 30%. Therefore, ESD is supporting less energy to both the grid and NBs. The comparison of ESD to e-bus curves from Fig. 3.14 and 3.16 shows the difference in ONB for ND and SD.
Fig. 3.16 The energy behaviour of ESD and SP for SD1
Vpu profile for SD2 is shown in Fig. 3.17. The energy behaviour of ESD and SP for SD2 is shown in Fig. 3.18. The Vpu profile of the grid has stayed under peak period during sunshine hours, so that the total SP energy has been sent to the grid and that can be observed from Fig.
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Vpu
Time (h)
Vpu actual Vpu resultant
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Energy (kWh)
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ESD SP ESD to e-bus
3.18. The off-peak period is existed from 21:00 to 09:00 h, from 15:00 to 16:00 h and from 17:00 to 19:00 h, so that ESD is receiving energy from the grid. Also, ESD is receiving energy from SP during 06:00 to 09:00 h, 15:00 to 16:00 h and 17:00 to 18:00 h, as shown in Fig. 3.18. The peak period is existed from 09:00 to 15:00 h, from 16:00 to 17:00 h and from 19:00 to 21:00 h, so that ESD is sending energy to the grid. Also, SP is sending energy to the grid from 09:00 to 15:00 h and from 16:00 to 17:00 h, as shown in Fig. 3.18.
Fig. 3.17 Vpu profile of the grid for SD2
Fig. 3.18 The energy behaviour of ESD and SP for SD2
The energy stored in ESD for ND, SD1 and SD2 are shown in Fig. 3.19.
Fig. 3.19 Energy stored in the ESD for ND, SD1 and SD2
Variations in the stored energy of ESD with respect to the load profiles of the grid can be observed from Fig. 3.19. For ND, the load profile of the grid has stayed under off-peak
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ND SD1 SD2
maximum amount of energy is available in ESD. For both SD1 and SD2, the load profile of the grid has stayed under peak period during the daytime and also, the energy demand from e-buses is high. Therefore, the minimum amount of energy is available in ESD.
ONB profiles for ND, SD1 and SD2 are shown in Fig. 3.20. Maximum priority has been given to provide the comfortable journey to the passengers in SDs. So that the maximum number of e-buses have been determined through ONB algorithm during peak periods of the passenger profile and that can be observed from Fig. 3.20.
Fig. 3.20 ONB profiles for ND, SD1 and SD2
Vpu profile for SD3 is shown in Fig. 3.21. The Vpu profile mostly stayed under off-peak period during the day-time. The maximum charging/discharging performance of ESD from/to the grid during off-peak /peak period can be observed from Fig. 3.21.
Fig. 3.21 Vpu profile of the grid for SD3
The energy behaviour of ESD and SP for SD3 is shown in Fig. 3.22. Vpu profile of the grid has stayed under off-peak period during sunshine hours, so that the total SP energy has been sent to ESD and that can be observed from Fig. 3.22. The off-peak period is existed from 23:00 to 18:00 h, so that ESD is receiving energy from the grid. The peak period is existed from 18:00 to 23:00 h, so that ESD is sending energy to the grid during this period.
The e-buses are receiving energy from ESD according to ONB for SDs. The ESD is
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ONB
Time (h)
ND SD1 SD2
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receiving less energy from the grid and maximum energy from SP. This means that the e- buses mostly travel with solar energy in SD3 and that can be observed from Fig. 3.22. The grid has remained under off-peak period during sunshine hours so that the SP is sending its total energy to ESD (solar irradiance availability is high for SD3) as shown in Fig. 3.22.
Fig. 3.22 The energy behaviour of ESD and SP for SD3
Vpu profile for SD4 is shown in Fig. 3.23. The SPTS receives maximum energy support from SP, if the grid stays under off-peak period during sunshine hours. For SD4, the Vpu profile mostly stayed under off-peak period during the day-time. Therefore, SPTS has utilized total SP energy in SD4 and that can be observed from Fig. 3.23. The maximum charging/discharging performance of ESD from/to the grid during off-peak/peak period and subsequent improvement in the Vpu profile for SD4 can be observed from Fig. 3.23.
Fig. 3.23 Vpu profile of the grid forSD4
The energy behaviour of ESD and SP for SD4 is shown in Fig. 3.24. The Vpu profile of the grid has stayed under off-peak period during sunshine hours, so that the total SP energy has been sent to the ESD and that can be observed from Fig. 3.24. The off-peak period is existed from 02:00 to 19:00 h, so that ESD is receiving energy from the grid. The peak period is existed from 19:00 to 02:00 h, so that ESD is sending energy to the grid during this period.
The e-buses are receiving energy from ESD according to ONB for SDs. The ESD is
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ESD SP ESD to e-bus
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availability is less for SD4, so that SP is sending less energy to ESD and that can be observed from Fig. 3.24.
Fig. 3.24 The energy behaviour of ESD and SP for SD4