Application of DVR based Trinary Hybrid Multilevel Inverter to Improve Power Quality of Sensitive Loads
In this paper, a new dynamic voltage restorer (DVR) based on a Trinary Hybrid Multilevel Inverter (THMI) is proposed, which is capable of compensating for voltage sag, swell and flickers for sensitive loads. A Trinary Hybrid nine-level inverter is composed of a smaller number of IGBTs and circuitry compared to similar structures. The base structure of this inverter is based on the connection of the H bridges and consists of two inverters of a single-phase bridge with a different DC voltage, each of which has a voltage of HB three times the previous HB. The inverter is also able to produce a number of higher output voltage levels and less harmonic distortion than cascade topologies, floating capacitors and diodes. This feature enables the structure to be used to compensate for the power quality of power distribution networks. Nearest Level Control (NLC) in the inverter is used to create the desired waveform. The In-Phase control method is selected to control the proposed DVR and use the synchronous reference frame (SRF) method to detect the network voltage fluctuations. To verify and validate the proposed DVR performance, simulations are carried out in the MATLAB / SIMULINK software environment, and the results indicate the optimal performance and desirability of the proposed DVR to compensate for the voltage sag, swell and flicker power distribution grids
 E. Akbari, A. Sheikholeslami and j. Rouhi, "operation DVR based Modular Multilevel Cascade Converter based on Double-star Chopper-cells (MMCC-DSCC) for Compensation Voltage sag and swell in Power Distribution Grids, Majlesi Journal of Mechatronic Systems (MJMS), Vol. 4, NO. 1, pp. 39-47, March 2015.
 A. Elnady and M. Salama, “Duall Role CDSC based Dual Vector Control for Effective Operation of DVR with Harmonic Mitigation” IEEE Transactions on Industrial Electronics, Vol. 16, No. 8, pp. 2614-2625, Nov 2018.
 S. P. Gautam and L. Kumar, “Hybrid topology of symmetrical multilevel inverter using less number of devices” IEEE Trans. Power Electron, Vol. 8, No. 11, pp. 3135-3145, Jan 2016.
 K. Gupta and A. Ranjan, “Multilevel inverter topologies with reduced device count a review” IEEE Trans. Power Electron, Vol. 31, No. 1, pp. 234-247, July2017.
 C. Silva and L. Cordova, “Implementation and control of a hybrid multilevel converter with floting DC links for current waveform improvement” IEEE Trans. Ind. Electron, Vol. 58, No. 6, pp. 1421-1432, May 2015.
 A. M. Rauf and V. Khadkikar, "An Enhanced Voltage Sag Compensation Scheme for Dynamic Voltage Restorer," IEEE Transactions on Industrial Electronics, vol. 62, no. 5, pp. 2683-2692, May 2015.
 Y. Liu, and F. Luo “Trinary hybrid 81-level multilevel inverter for motor drive with zero common-mode voltage” IEEE Trans. Power Electron, Vol. 30, No. 1, pp. 450-462, Aug 2008.
 P. M. Meshram, V. B. Borghate and F. Nugater “A simplified nearest level control (NLC) voltage balancing method for modular multilevel converter (MMC)” IEEE Trans. Power Electron, Vol. 30, No. 1, pp. 450-462, Aug 2017.
 E. Ebrahimzadeh, S. Farhangi, H. Iman-Eini, F. Badrkhani Ajaei and R. Iravani, "Improved Phasor Estimation Method for Dynamic Voltage Restorer Applications," IEEE Transactions on Power Delivery, vol. 30, no. 3, pp. 1467-1477, June 2016.