PV-Battery Powered Direct Torque ControlledSwitched Reluctance Motor Drive

ABSTRACT:

 Categorized as one of the renewable energies, Photo- Voltaic system has a great potential compared to its counterparts of renewable energies. This paper deals with the design of a Photovoltaic (PV)-Battery fed Switched Reluctance Motor(SRM). The system mainly composed of a PV module, boost converter, rechargeable battery, bidirectional converter, asymmetric bridge converter, SRM and system controllers. The main problems of SRM are high torque ripple, acoustic noise and vibration problems. In order to reduce these problems, a new direct torque control of 3.5 kW 8/6 SRM is proposed, which is simple and can be implemented with low cost processor. It can be seen from the simulation results that this scheme has well regulated the torque output of the motor with in hysteresis band. The proposed system assures its suitability for solar applications like solar vehicles, solar water pumping system and floor mills in hilly and isolated areas.

KEYWORDS:

  1. PV module
  2. Switched reluctance motor
  3. Direct torque control
  4. Battery energy storage system

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Figure 1. (a)PV-Battery fed Induction Motor drive (b) PV-Battery Switched Reluctance Motor drive

EXPECTED SIMULATION RESULTS:

Figure 2. Variation of PV output voltage and current due variation in solar Radiation

Figure 3. Control of flux vector with in hysteresis band

Figure 4. Flux trajectory in d-q plane

 

Figure 5. Current waveform of different phases

Figure 6. Control of torque in hysteresis band

Figure 7. Flux waveform of different phases

 CONCLUSION:

 The proposed scheme reduces dc link voltage there by reducing capacitor size and insulation level. A single stage conversion is also possible without the use of boost converter. The advantage of using asymmetric bridge converter is freedom to control individual phase independently and no shoot through fault. Torque ripple in the SRM can be eliminated by Direct Torque Control technique. The results indicate that DTC of SRM can directly regulate the torque output of the motor within a hysteresis band.

REFERENCES:

 [1] Jewell W.T and Ramkumar R “The history of utility –interactive photovoltaic generation”,IEEE/PES procedings ,Vol 30 pp1-5,Feb 1988.

[2] J. Applebaum J and Sarma M.S;“The operation of permanent magnet dc motors powered by a common source of solar cells,.” IEEE Trans. On EC., ,Vol. 4, pp.635-641, dec 1989 .

[3] Putta Swamy C L, Singh Bhim and Singh B P; “Dynamic performance of permanent magnet brushless DC powered by a PV array for water pumping,. ”Journel of Solar materials and Solar cells, ,Vol. 36, No.2 pp.187-200,1995

[4] Bhat S.R, Pittet A and Sonade B S; “Performance optimization ofinduction motor pump system using photovoltaic source,.”IEEE Transon Industrial Applications., ,Vol. 23, No 6 pp.955-1000, Nov/Dec 1987.

[5] Daud, and M. Mahmoud; “Solar Power Induction Motor Drive WaterPump Operating on a Desert Well, Simulation and Field Test”,,.” IEEE Trans.on Renewable Energy, ,Vol. 30, pp.701-714,2005.

Power quality improvement in distribution network using DSTATCOM with battery energy storage system

ABSTRACT

The distribution static compensator (DSTATCOM) provides fast control of active and reactive powers to enable load compensation, harmonics current elimination, voltage flicker mitigation, voltage and frequency regulation. This paper presents power quality improvement technique in the presence of grid disturbances and wind energy penetration using DSTATCOM with battery energy storage system. DSTATCOM control is provided based on synchronous reference frame theory. A modified IEEE 13 bus test feeder with DSTATCOM and wind generator is used for the study. Power quality events during grid disturbances such as feeder tripping and re-closing, voltage sag, swell and load switching have been studied in association with DSTATCOM. The power quality disturbances due to wind generator outage, synchronization and wind speed variations have also been investigated. The study has been carried out using MATLAB/SIMULINK and the simulation results are compared with real time results obtained by the use of real time digital simulator (RTDS) for validating the effectiveness of proposed methodology. The proposed method has been proved to be effective in improvement of power quality with all disturbances stated above.

 

KEYWORDS

  1. Battery energy storage system
  2. Radial distribution feeder
  3. DSTATCOM
  4. Synchronous reference frame theory

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig.1. Proposed DSTATCOM with BESS.

 

SIMULATION RESULTS

Fig.2. Feeder tripping and re-closing without DSTATCOM in the network (a) RMS voltage at bus 632, (b) active power flow and (c) reactive power flow

Fig.3. Feeder tripping and re-closing with DSTATCOM in the network (a) RMS voltage at bus 632, (b) active power flow and (c) reactive power flow

Fig.4. Load switching without DSTATCOM in the network (a) RMS voltage at bus 632, (b) active power flow and (c) reactive power flow

Fig.5. Load switching with DSTATCOM in the network (a) RMS voltage at bus 632, (b) active power flow and (c) reactive power flow.

Fig.6. Voltage sag and swell (a) without DSTATCOM, (b) with DSTATCOM and (c) reactive power flow during voltage sag and swell.

Fig. 7 Wind synchronization (a) voltage without DSTATCOM, (b) voltage with DSTATCOM, (c) active power flow with DSTATCOM and (d) reactive power flow with DSTATCOM.

Fig. 8. Wind outage (a) voltage without DSTATCOM, (b) voltage with DSTATCOM, (c) active power flow with DSTATCOM and (d) reactive power flow with DSTATCOM

Fig. 9. Wind speed variation.

 

CONCLUSION

The proposed research work investigates into PQ events associated with distribution network due to grid disturbances such as voltage sag, swell, load switching, feeder tripping and re-closing. The DSTATCOM has been proposed to improve the power quality in the above events. The proposed DSTATCOM with SRF based control has been proved to be effective in improving the power quality in these events at grid level. The power quality events associated with wind operations such as wind generator outage, grid synchronization of wind generator and wind speed variations have been improved by the use of proposed DSTATCOM in the distribution network. From, these studies it has been established that the DSTATCOM can effectively be used to improve the power quality in the distribution network with wind generation and during grid disturbances. The results have been validated in real time utilizing RTDS. The real time results are very close to the simulation results which shows the effectiveness of proposed DSTATCOM with BESS for improvement of PQ in the distribution system.

 

REFERENCES

  • Ibrahim W, Morcos M. A power quality perspective to system operational diagnosis using fuzzy logic and adaptive techniques. IEEE Trans Power Deliv 2003;18(3):903–9. http://dx.doi.org/10.1109/TPWRD.2003.813885.
  • Ray P, Mohanty S, Kishor N. Classification of power quality disturbances due to environmental characteristics in distributed generation system. IEEE TransSust Energy 2013;4(2):302–13. http://dx.doi.org/10.1109/TSTE.2012.2224678.
  • Tascikaraoglu A, Uzunoglu M, Vural B, Erdinc O. Power quality assessment of wind turbines and comparison with conventional legal regulations: a case study in turkey. Appl Energy 2011;88(5):1864–72. http://dx.doi.org/10.1016/j. apenergy.2010.12.001.
  • Dash P, Padhee M, Barik S. Estimation of power quality indices in distributed generation systems during power islanding conditions. Int J Electr Power Energy Syst 2012;36(1):18–30. http://dx.doi.org/10.1016/j.ijepes.2011.10.019.
  • Mahela OP, Shaik AG, Gupta N. A critical review of detection and classification of power quality events. Renew Sust Energy Rev 2015;41(0):495–505. http:// dx.doi.org/10.1016/j.rser.2014.08.070.

Residential Photovoltaic Energy Storage System

 

ABSTRACT:

This paper introduces a residential photovoltaic (PV) energy storage system, in which the PV power is controlled by a dc–dc converter and transferred to a small battery energy storage system (BESS). For managing the power, a pattern of daily operation considering the load characteristic of the homeowner, the generation characteristic of the PV power, and the power leveling demand of the utility is prescribed. The system looks up the pattern to select the operation mode, so that powers from the PV array, the batteries, and the utility are utilized in a cost-effective manner. As for the control of the system, a novel control technique for the maximum power-point tracking (MPPT) of the PV array is proposed, in which the state-averaged model of the dc–dc converter, including the dynamic model of the PV array, is derived. Accordingly, a high-performance discrete MPPT controller that tracks the maximum power point with zero-slope regulation and current-mode control is presented. With proposed arrangements on the control of the BESS and the current-to-power scaling factor setting, the dc–dc converter is capable of combining with the BESS for performing the functions of power conditioning and active power filtering. An experimental 600-W system is implemented, and some simulation and experimental results are provided to demonstrate the effectiveness of the proposed system.

KEYWORDS:

  1. Active power filtering
  2. Battery energy storage system
  3. Maximum power-point tracking
  4. Power conditioning

SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Fig. 1. The power circuit of proposed PV energy storage system.

EXPECTED SIMULATION RESULTS:

 

Fig. 2. Simulated results of MPPT control. (a) An increasing step change in Ip. (b) A decreasing step change in Ip.

Fig. 3. Measured waveforms of  , and    in MPPT control.

Fig. 4. System operations. (a) Measured waveforms when system is changed from mode 3 to mode 2, where subscripts o;L; and u are used to represent the BESS, the load, and the utility, respectively. (b) Measured real power waveforms in various operation modes.

CONCLUSION:

This paper has proposed a residential PV energy storage system, where the PV power is controlled by a dc–dc converter and transferred to a small BESS. The proposed system, possessing the functions of power conditioner and active power filter, is capable of providing an optimal interface with the utility. The additional PV power makes the system flexible in power usage, so that all powers in the system can be utilized in a cost-effective manner. Some control techniques for realizing the functions of the proposed system, including the MPPT control of the PV array and control of power flows in the system, have been presented. A prototype 600-W system was implemented, and some simulated and experimental results were provided to demonstrate the effectiveness of the proposed system. Although the setup cost of the proposed system is high, such that it is hard to compete with the current utility power, we believe that the capital issue will be resolved if there is a political encouragement in the kilowatt price and the market is large enough.

REFERENCES:

[1] G. J. Jones, “The design of photovoltaic systems for residential applications,” in Conf. Rec. IEEE Photovoltaic Specialists Conf., 1981, pp. 805–810.

[2] G. L. Campen, “An analysis of the harmonics and power factor effects at a utility intertied photovoltaic system,” IEEE Trans. Power App. Syst., vol. PAS-101, pp. 4632–4639, Dec. 1982.

[3] C. M. Liaw, T. H. Chen, S. J. Chiang, C. M. Lee, and C. T. Wang, “Small battery energy storage system,” Proc. Inst. Elect. Eng., vol. 140, pt. B, no. 1, pp. 7–17, 1993.

[4] S. J. Chiang, “Design and implementation of multi-functional battery energy storage systems,” Ph.D. dissertation, Dep. Elect. Eng., National Tsing Hua University, Hsin-Chu, Taiwan, R.O.C., 1994.

[5] Z. Salameh and D. Taylor, “Step-up maximum power point tracker for photovoltaic arrays,” Sol. Energy Proc., vol. 44, no. 1, pp. 57–61, 1990.