Power Quality Enhancement Using Dynamic Voltage Restorer (DVR)-Based Predictive Space Vector Transformation (PSVT) With Proportional Resonant (PR)-Controller

Abstract

 In the power distribution system, the Power Quality (PQ) is disturbed by the voltage sag and swells. The Dynamic Voltage Restorer (DVR) is used to enhance various PQ problems like voltage sag, swells, and Harmonics. The previous Intrinsic Space Vector Transformation (ISVT) control techniques with DVR system, to compensate the power quality issue. It produced a steady-state error, low efficiency, and high THD. The SMES based DVR has provided excellent results in overcoming these issues. The energy is stored by DVR through a storage element, which takes alternate energy from a Solar PV cell. The Maximum Power Point Tracking (MPPT) based P&O algorithm is implemented to equalize the solar power. The Voltage Source Inverter (VSI) generates the reactive power, which has to be compensated with the help of Pulse Width Modulation (PWM) and the feedback control loop are essential to enhance the injection of reactive power to the line. Due to this reason, a proposed Predictive Space Vector Transformation (PSVT) control-based DVR is implemented. It analyzes the variation of power on the distribution side and generates the proper feedback control to the inverter systems. In the instant of voltage injection to the line with the help of DVR, the phase angle mismatch happens which is not synchronized reactive power to the grid. Due to the non-synchronization of reactive power, more harmonic distortion is generated. A Proportional Resonant (PR) controller is introduced, which is Proportional Resonant (PR) current controller. The current injected by the inverter into the grid in phase with the grid voltage maintain constant with unity power factor. The PR controller design is cascaded with a harmonic compensator to mitigate low order odd harmonic components present in the output current of VSI and minimize the total harmonic distortion (THD). The performance of the proposed is evaluated using MATLAB 2017b software.

Index Terms

DVR, predictive space vector transformation (PSVT), PR-controller, PQ, VSI, THD, MPPT

based P&O algorithm.

Proposed Circuit:

 

Figure 1. Proposed DVR control scheme.

Expected Simulation Results:

Figure 2. Load Power Stabilization Of 500watts And 1000w System waveforms in the compensation of voltage sags and harmonic distortion. (a_c) feeder 1 waveforms; (d_f) feeder 2 waveforms; (g) virtual dc-link Voltage Waveform.

 

Figure 3. Voltage And Current In-Phase Waveform.

 

Figure 4. Voltage Sag With Resistive Load.(1) Load Voltage, Grid voltage (2) dclink voltage, (3) grid voltage of source side converter, source current.

 

Figure 5. Voltage Swell With Resistive Load. (I) Load Voltage, Grid Voltage (ii): dc-link voltage (iii): grid voltage of source side converter.

 

                               Figure 6. Single Line Load Voltage Waveform With Sag/Swell compensation.

 

                                       Figure 7. Waveforms Of Shunt And Series Converter With Sag In Grid voltage.

 

 Conclusion

In this work, a DVR-PSVT based PR controller power compensation model was implemented to compensate for the grid power fluctuations. The purpose of the PSVT controller is to vary the PWM of the inverter and to use the DVR offset to generate the appropriate reactive power and maintain the power quality. The proposed PR control system includes the possibility of turning their individual resonant peaks to the grid frequency, while injecting the compensated voltage through DVR based PSVT system. The PR controller required lesser computational overhead and also not required an explicit grid voltage feed forwarder control path in DVR system. For three phase grid connected system, the PR technique compensating for both positive and negative sequence simultaneously, there is no need for synchronous reference frame. In case of PI controller, the synchronous reference frame is required to compensate the positive and negative sequence voltage. The output of the PR controller with DVR system provides better performance compared with conventional controller and the THD of the proposed system was very low. The DVR-PSVT based PR controller was compensate the voltage sag, voltage swell and reduced the THD to 1.06% at the time of reactive power compensation to the grid. The results show that the integrated DVR - PSVT based PR control technologies can maintain optimal power flow in the power supply system and power distribution system. This makes it an attractive solution to deal with voltage sag, swell and Harmonic of PQ problems. On the other hand, the proposed PR controller topology presents many development opportunities for future research, including

1. The implementation of a prototype for experimental tests.

2. Interfacing the Grid with line the compensation of voltage sag device which produced good quality of power in hybrid micro-grids.

3. Improving the reliability of micro-grid.

References

[1] E. Hossain, M. R. Tur, S. Padmanaban, S. Ay, and I. Khan, ``Analysis and mitigation of power quality issues in distributed generation systems using custom power devices,'' IEEE Access, vol. 6, pp. 1681616833, 2018.

[2] M. Pradhan and M. K. Mishra, ``Dual P��Q theory based energy-optimized dynamic voltage restorer for power quality improvement in a distribution system,'' IEEE Trans. Ind. Electron., vol. 66, no. 4, pp. 29462955, Jun. 2018.

[3] S. Patra, N. Kishor, S. R. Mohanty, and P. K. Ray, ``Power quality assessment in 3- grid connected pv system with single and dual stage circuits,'' Int. J. Electr. Power Energy Syst., vol. 75, pp. 275288, Feb. 2016.

[4] O. P. Mahela, A. G. Shaik, N. Gupta, M. Khosravy, B. Khan, H. H. Alhelou, and S. Padmanaban, ``Recognition of power quality issues associated with grid integrated solar photovoltaic plant in experimental framework,'' IEEE Syst. J., vol. 15, no. 3, pp. 37403748, Sep. 2021.

[5] A. A. Alkahtani, S. T. Y. Alfalahi, A. A. Athamneh, A. Q. Al-Shetwi, M. B. Mansor, M. A. Hannan, and V. G. Agelidis, ``Power quality in microgrids including supraharmonics: Issues, standards, and mitigations,'' IEEE Access, vol. 8, pp. 127104127122, 2020.

An Efficient Inductive Power Transfer Topology for Electric Vehicle Battery Charging

Abstract

 Recently available high-frequency power converter topologies for inductive power transfer (IPT) system utilize either zero voltage switching (ZVS) or zero current switching (ZCS) based power electronic converters while maintaining a near sinusoidal current for limited power transfer range. However, achieving ZVS or ZCS for all power switches simultaneously is still a challenging task in IPT systems. In this article, an improved zero-voltage zero-current switching (ZVZCS) IPT topology and its switching pattern are proposed. ZVS is achieved by optimizing the classical series compensation and additionally, an auxiliary network is employed to achieve ZCS. The proposed concept is verified by using MATLAB/Simulink based simulations for resistive and battery load. Finally, the practical viability of the proposed topology is validated by the results obtained using a laboratory prototype rated for 1.1kW, 85 kHz.An efficiency of 91.26% is achieved with ZVZCS for a full dynamic power transfer range of 20W–1.1 kW.

Index Terms

Battery chargers, dc–dc power converters, electric vehicles (EVs), inductive charging, soft switching, wireless power transmission.

Block diagram:

 

Fig. 1. General configuration of wireless battery charger topology.

Expected simulation results:

 

 

Fig. 2. ZCS turn-OFF for (a) S2 and (b) S4.

 

Fig. 3. Converter characteristics waveform in various operating modes.

 

Fig. 4. Input side characteristic of primary network.

 

Fig. 5. Output characteristic for BC application

Conclusion

 In this article, the voltage fed series compensation based ZVZCS topology and its tuning method for wireless electrical vehicle battery charger have been proposed. Suitable modifications were presented for the full-bridge dc–dc converter, and enhanced performance with a wide range of input variation is achieved. The need for a high-power processor is eliminated, which further reduces the overall cost. The theoretical analysis and modeling have been presented to obtain ZVZCS with reduced control complexity. The simulation results verified the ZVZCS condition of the proposed topology for a full load range. The offered solution produced less ripple in input/ output voltage and current while utilizing a low value of dc link, and filter capacitance values, respectively. An acceptable efficiency of 91.26% has been achieved for both battery and resistive loads.

References

 

[1] M. Granovskii, I. Dincer, and M. A. Rosen, “Economic and environmental comparison of conventional, hybrid, electric and hydrogen fuel cell vehicles,” J. Power Sources, vol. 159, no. 2, pp. 1186–1193, 2006.

[2] S. B. Peterson, J. Whitacre, and J. Apt, “The economics of using plug-in hybrid electric vehicle battery packs for grid storage,” J. Power Sources, vol. 195, no. 8, pp. 2377–2384, 2010.

[3] Y. Zhou, M. Wang, H. Hao, L. Johnson, and H. Wang, “Plug-in electric vehicle market penetration and incentives: A global review,” Mitigation Adaptation Strategies Global Change, vol. 20, no. 5, pp. 777–795, 2015.

[4] B. Nykvist and M. Nilsson, “Rapidly falling costs of battery packs for electric vehicles,” Nature Climate Change, vol. 5, no. 4, pp. 329–332, 2015.

[5] W. Zhang and C. C. Mi, “Compensation topologies of high-power wireless power transfer systems,” IEEE Trans. Veh. Technol., vol. 65, no. 6, pp. 4768–4778, Jun. 2016.

A New Technique Implemented in Synchronous Reference Frame for DVR Control Under Severe Sag and Swell Conditions

Abstract

Nowadays, power quality under the excessive implementation of power electronics devices is quite challenging issue. The compensation of non-sinusoidal; reactive and harmonic; components is the main role for power quality devices which highly depend on the robustness of the control system. Some common control systems are implemented using Synchronous Stationary Frame (DQ) theory. This paper proposes a new version of DQ control technique to control dynamic voltage restorer under severe transient voltage conditions. The power system network with the new DQ control technique is studied and analyzed under different scenarios to compensate for severe balanced and unbalanced voltage sags and swells. This new scheme is based on extraction of positive sequence components to implement the control algorithm. A mathematical model of the dynamic voltage restorer (DVR), hysteresis voltage control, converter controller model, new DQ scheme with complete system equations are carried out and verified using Simulink / MATLAB. The proposed system is validated experimentally using D Space 1104 based laboratory system. The obtained results of the proposed compensation algorithm are compared with the results obtained from the traditional DQ method. Simulation and experimental results are correlated and show effectiveness of the proposed DQ control scheme.

Index Terms

Balance and unbalanced load, dynamic voltage restorer (DVR), instantaneous space vector, synchronous stationary frame (DQ) theory, voltage sag, voltage swell.

Circuit diagram:

 

 Figure 1. Basic Circuit Of Power System With DVR.

Expected Simulation Results:

 

Figure 2. Simulation Results Of Grid Voltages, Load Voltage And DVR Voltages (Traditional DQ) Under Balanced 3' Grid Voltage Sag Of 20%.

 

 

Figure 3. Simulation Results Of Grid Voltages, Load Voltage And Dvr Voltages (Modified Dq) Under Balanced 3' Grid Voltage Sag Of 20%.

 Figure 4. Simulation Results Of Grid Voltages, Load Voltage And Dvr Voltages (Traditional Dq) Under Balanced 3' Grid Voltage Swell Of 70%.

 

 Figure 5. Simulation Results Of Grid Voltages, Load Voltage And Dvr Voltages (Modified Dq) Under Balanced 3' Grid Voltage Swell Of 70%.

 

 

Figure 6. Simulation Results Of Grid Voltages, Load Voltage And Dvr Voltages (Traditional Dq) Under Unbalanced 3' Grid Voltage Sag Of 20%.

 

Figure 7. Simulation Results Of Grid Voltages, Load Voltage And Dvr Voltages (Modified Dq) Under Unbalanced 3' Grid Voltage Sag Of 20%.

 

Figure 8. Simulation Results Of Grid Voltages, Load Voltage And Dvr Voltages (Traditional Dq) Under Unbalanced 3' Grid Voltage Swell Of 70%.

 Figure 9. Simulation Results Of Grid Voltages, Load Voltage And Dvr Voltages (Modified Dq) Under Unbalanced 3' Grid Voltage Swell Of 70%.

 

Conclusion

This paper inspects the control of DVR with modified DQ algorithm to generate reference voltage signals to control the DVR. The proposed DVR control method relies on a modified version of DQ theory with a detection method for the positive and negative sequence components. The modelled simulations are carried out in MATLAB Simulink and the results were validated with Experimental setup carried out on DSPACE 1104 module. The results are shown good correlation between simulation and experimental results. The control of modified DQ method is compared with the traditional DQ control technique under the conditions of severe sag and swell. The performance of the controllers is also compared during balanced and unbalanced situation with severe cases of sag and swell. The comparative results suggest that the new modified DQ control method shows effective in compensating voltage during severe sag swell in balance and unbalance conditions with advantages of

· Less computational effort.

· Faster response.

· Less transient oscillation in the fundamental frequency under unbalanced voltage sag and swell.

References

[1] S. Hasan, K. Muttaqi, D. Sutanto, and M. A. Rahman, ``A novel dual slope delta modulation technique for a current source inverter based dynamic voltage restorer for mitigation of voltage sags,'' IEEE Trans. Ind. Appl., vol. 57, no. 5, pp. 54375447, Sep. 2021, doi: 10.1109/TIA.2021.3089984.

[2] B. Bae, J. Jeong, J. Lee, and B. Hen, ``Novel sag detection method for lineinteractive dynamic voltage restorer,'' IEEE Trans. Power Del., vol. 25, no. 2, pp. 12101211, Apr. 2010, doi: 10.1109/TPWRD.2009.2037520.

[3] M. Vilathgamuwa, A. A. D. Ranjith, S. S. Choi, and K. J. Tseng, ``Control of energy optimized dynamic voltage restorer,'' in Proc. IECON Conf. 25^th Annu. Conf. IEEE Ind. Electron. Soc., vol. 3, Dec. 1999, pp. 873878.

[4] P. Li, L. Xie, J. Han, S. Pang, and P. Li, ``New decentralized control scheme for a dynamic voltage restorer based on the elliptical trajectory compensation,'' IEEE Trans. Ind. Electron., vol. 64, no. 8, pp. 64846495, Aug. 2017, doi: 10.1109/TIE.2017.2682785.

[5] N. C. S. Sarita, S. S. Reddy, and P. Sujatha, ``Control strategies for power quality enrichment in distribution network using UPQC,'' Mater. Today, Proc., vol. 10, Feb. 2022, doi: 10.1016/j.matpr.2021.07.053.