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.
- Battery energy storage system
- Radial distribution feeder
- Synchronous reference frame theory
Fig.1. Proposed DSTATCOM with BESS.
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.
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.
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