Modern energy resources, such as photovoltaics, batteries, wind, and electric vehicles are interfaced to the grid through power electronics. These interfaces are fundamentally distinct from conventional synchronous generators in that they do not contain moving parts and their dynamics are shaped with digital controls. As generation shifts from large rotating machines to collections of electronic interfaces dispersed across the grid, system dynamics will accelerate under reduced inertia and system structures will become increasingly decentralized. Our group is reimagining the way grids are built and stands at the forefront of grid-forming inverter technologies that enable scalable and resilient power systems. UT Austin is also a co-lead of the UNIFI Consortium.

low inertia

Selected Publications

2024

46.

Cai, Weiqian; Mallik, Rahul; Johnson, Brian

Singular-perturbation-based control design of single-phase grid-forming inverters Proceedings Article

In: Energy Conversion Congress and Exposition, 2024.

Links | BibTeX | Tags: inverter control, inverters

45.

Mallik, Rahul; Chatterjee, Debjyoti; Johnson, Brian

Fault ride-through for cascaded inverters using mixed grid-forming and grid-following control Proceedings Article

In: Energy Conversion Congress and Exposition, 2024.

Links | BibTeX | Tags: inverter control, inverters

44.

Baeckeland, Nathan; Chatterjee, Debjyoti; Lu, Minghui; Johnson, Brian; Seo, Gab-Su

Overcurrent limiting in grid-forming inverters: A comprehensive review and discussion Journal Article

In: IEEE Transactions on Power Electronics, 2024.

Links | BibTeX | Tags: inverter control, inverters, review

43.

Baeckeland, Nathan; Ankner, Thomas; Dhople, Sairaj; Johnson, Brian; Seo, Gab-Su

Equivalent-circuit models of grid-forming IBRs for electromagnetic-transient simulations Proceedings Article

In: Power and Energy Society General Meeting, 2024.

Links | BibTeX | Tags: inverters, modeling

2023

42.

Cai, Weiqian; Lu, Minghui; Johnson, Brian

Inverter-based emulation of single-phase air conditioner loads Proceedings Article

In: Energy Conversion Congress and Exposition, 2023.

Links | BibTeX | Tags: electromechanics, inverter control, inverters, modeling

41.

Lu, Minghui; Cai, Weiqian; Dhople, Sairaj; Johnson, Brian

Large-signal stability of phase-balanced equilibria in single-phase grid-forming inverter systems Journal Article

In: IEEE Transactions on Power Electronics, 2023.

Links | BibTeX | Tags: inverters, modeling, systems

40.

Pal, Diptak; Panigrahi, Bijaya Ketan; Johnson, Brian; Venkatramanan, D; Dhople, Sairaj

Large-signal stability analysis of three-phase grid-following inverters Journal Article

In: IEEE Transactions on Energy Conversion, 2023.

Links | BibTeX | Tags: inverters, modeling

39.

Ramasubramanian, Deepak; Kroposki, Benjamin; Dhople, Sairaj; Groß, Dominic; Hoke, Anderson; Wang, Wenzong; Shah, Shahil; Hart, Philip; Seo, Gab-Su; Ropp, Michael; Du, Wei; Vittal, Vijay; Ayyanar, Raja; Flicker, Jack; Benzaquen, Joseph; Johnson, Brian; Arsuaga, Pedro; Achilles, Sebastian; Pant, Siddharth; Bhattarai, Rojan; Howard, Dustin; Gong, Maozhong; Divan, Deepak; Tuohy, Aidan

Performance specifications for grid-forming technologies Proceedings Article

In: Power and Energy Society General Meeting, 2023.

Links | BibTeX | Tags: inverter control, inverters, systems

38.

Ramasubramanian, Deepak; Farantatos, Evangelos; Ajala, Olaoluwapo; Dhople, Sairaj; Johnson, Brian

A universal grid-forming inverter model and simulation-based characterization across timescales Proceedings Article

In: Hawaii International Conference on System Sciences, 2023.

Links | BibTeX | Tags: inverters, modeling, systems

2022

37.

Ajala, Olaoluwapo; Baeckeland, Nathan; Johnson, Brian; Dhople, Sairaj; Domínguez-García, Alejandro

Model reduction and dynamic aggregation of grid-forming inverter networks Journal Article

In: IEEE Transactions on Power Systems, 2022.

Links | BibTeX | Tags: inverters, systems

36.

Mallik, Rahul; Majmunović, Branko; Dutta, Soham; Seo, Gab-Su; Maksimović, Dragan; Johnson, Brian

Control design of series-connected PV-powered grid-forming converters via singular perturbation Journal Article

In: IEEE Transactions on Power Electronics, 2022.

Links | BibTeX | Tags: converter design, inverters

35.

Majmunović, Branko; Mukherjee, Satyaki; Martin, Trent; Mallik, Rahul; Dutta, Soham; Seo, Gab-Su; Johnson, Brian; Maksimović, Dragan

1 kV, 10-kW SiC-based quadruple active bridge DCX stage in a DC to three-phase AC module for medium-voltage grid integration Journal Article

In: IEEE Transactions on Power Electronics, 2022.

Links | BibTeX | Tags: converter design, inverters

34.

Lu, Minghui; Dhople, Sairaj; Zimmanck, Donny; Johnson, Brian

Spontaneous phase balancing in delta-connected single-phase droop-controlled inverters Journal Article

In: IEEE Transactions on Power Electronics, 2022.

Links | BibTeX | Tags: converter design, inverters

33.

Johnson, Brian; Roberts, T. G.; Ajala, Olaolu; Dominguez-Garcia, Alejandro; Dhople, Sairaj; Ramasubramanian, Deepak; Tuohy, Aidan; Divan, Deepak; Kroposki, Benjamin

A generic primary-control model for grid-forming inverters: Towards interoperable operation and control Proceedings Article

In: Hawaii International Conference on System Sciences, pp. 3398-3407, 2022.

Links | BibTeX | Tags: inverter control, inverters, modeling

32.

Lu, Minghui; Dhople, Sairaj V.; Johnson, Brian

Benchmarking nonlinear oscillators for grid-forming inverter control Journal Article

In: IEEE Transactions on Power Electronics, pp. 1-1, 2022.

Links | BibTeX | Tags: inverters

31.

Son, Yeongrack; Mukherjee, Satyaki; Mallik, Rahul; Majmunovi'c, Branko; Dutta, Soham; Johnson, Brian; Maksimovi'c, Dragan; Seo, Gab-Su

Levelized cost of energy-oriented modular string inverter design optimization for PV generation system using geometric programming Journal Article

In: IEEE Access, vol. 10, pp. 27561-27578, 2022.

Links | BibTeX | Tags: inverters

30.

Lin, Yashen; Eto, Joseph; Johnson, Brian; Flicker, Jack; Lasseter, Robert; Pico, Hugo Villegas; Seo, Gab-Su; Pierre, Brian; Ellis, Abraham; Miller, Jeremiah; Yuan, Guohui

Pathways to the next-generation power system with inverter-based resources: Challenges and recommendations Journal Article

In: IEEE Electrification Magazine, vol. 10, no. 1, pp. 10-21, 2022.

Links | BibTeX | Tags: inverters, systems

2021

29.

Lu, Minghui; Dutta, Soham; Johnson, Brian

Self-synchronizing cascaded inverters with virtual oscillator control Journal Article

In: IEEE Transactions on Power Electronics, pp. 1-1, 2021.

Links | BibTeX | Tags: inverters, systems

28.

Ajala, Olaoluwapo; Lu, Minghui; Dhople, Sairaj; Johnson, Brian; Domínguez-García, Alejandro

Model reduction for inverters with current limiting and dispatchable virtual oscillator control Journal Article

In: IEEE Transactions on Energy Conversion, pp. 1-1, 2021.

Links | BibTeX | Tags: inverters, modeling

27.

Lu, Minghui; Purba, Victor; Dhople, Sairaj; Johnson, Brian

Unified equivalent-circuit models for voltage-source inverters that capture averaged dynamics and power-flow solutions in distribution networks Proceedings Article

In: Hawaii International Conference on System Sciences, pp. 1–10, 2021.

Links | BibTeX | Tags: inverters, modeling

26.

Dutta, Soham; Lu, Minghui; Majmunović, Branko; Mallik, Rahul; Seo, Gab-Su; Maksimović, Dragan; Johnson, Brian

Grid-connected self-synchronizing cascaded H-bridge inverters with autonomous power sharing Proceedings Article

In: Energy Conversion Congress and Exposition, pp. 2806–2813, IEEE 2021.

Links | BibTeX | Tags: inverters, systems

25.

Venkatramanan, D; Vamanan, Nimesh; Johnson, Brian; Dhople, Sairaj

Quantitative analysis of third-harmonic neutral-point current, its impacts, and mitigation in three-level NPC inverters Proceedings Article

In: Energy Conversion Congress and Exposition, pp. 3563–3570, IEEE 2021.

Links | BibTeX | Tags: inverters, modeling

24.

Lu, Minghui; Mallik, Rahul; Johnson, Brian; Dhople, Sairaj

Dispatchable virtual-oscillator-controlled inverters with current-limiting and MPPT capabilities Proceedings Article

In: Energy Conversion Congress and Exposition, pp. 3316–3323, IEEE 2021.

Links | BibTeX | Tags: inverters

23.

Venkatramanan, D; Johnson, Brian; Dhople, Sairaj

Averaged dynamic model of three-level NPC grid-following inverter for examining neutral-point instability Proceedings Article

In: Workshop on Control and Modeling of Power Electronics, pp. 1–7, IEEE 2021.

Links | BibTeX | Tags: inverters, modeling

2020

22.

Dutta, Soham; Lu, Minghui; Mallik, Rahul; Majmunović, Branko; Mukherjee, Satyaki; Seo, Gab-Su; Maksimović, Dragan; Johnson, Brian

Decentralized control of cascaded H-bridge inverters for medium-voltage grid integration Proceedings Article

In: Workshop on Control and Modeling for Power Electronics, pp. 1–6, IEEE 2020.

Links | BibTeX | Tags: inverters, systems

21.

Lu, Minghui; Purba, Victor; Dhople, Sairaj; Johnson, Brian

Comparison of droop control and virtual oscillator control realized by Andronov-Hopf dynamics Proceedings Article

In: Conference of the IEEE Industrial Electronics Society, pp. 4051–4056, IEEE 2020.

Links | BibTeX | Tags: inverters, modeling

20.

Lu, Minghui; Dutta, Soham; Purba, Victor; Dhople, Sairaj; Johnson, Brian

A pre-synchronization strategy for grid-forming virtual oscillator controlled inverters Proceedings Article

In: Energy Conversion Congress and Exposition, pp. 4308–4313, IEEE 2020.

Links | BibTeX | Tags: inverters

2019

19.

Lu, Minghui; Dutta, Soham; Purba, Victor; Dhople, Sairaj; Johnson, Brian

A grid-compatible virtual oscillator controller: Analysis and design Proceedings Article

In: Energy Conversion Congress and Exposition, pp. 2643–2649, IEEE 2019.

Links | BibTeX | Tags: inverters

18.

Seo, Gab-Su; Colombino, Marcello; Subotic, Irina; Johnson, Brian; Gross, Dominic; Dörfler, Florian

Dispatchable virtual oscillator control for decentralized inverter-dominated power systems: Analysis and experiments Proceedings Article

In: Applied Power Electronics Conference, pp. 561–566, IEEE 2019.

Links | BibTeX | Tags: inverters

17.

Lu, Minghui; Seo, Gab-Su; Sinha, Mohit; Rodriguez, Fernando; Dhople, Sairaj; Johnson, Brian

Adaptation of commercial current-controlled inverters for operation with virtual oscillator control Proceedings Article

In: Applied Power Electronics Conference, pp. 3427–3432, IEEE 2019.

Links | BibTeX | Tags: inverters

2018

16.

Purba, Victor; Johnson, Brian; Rodriguez, Miguel; Jafarpour, Saber; Bullo, Francesco; Dhople, Sairaj

Reduced-order aggregate model for parallel-connected single-phase inverters Journal Article

In: IEEE Transactions on Energy Conversion, vol. 34, no. 2, pp. 824–837, 2018.

Links | BibTeX | Tags: inverters, modeling

15.

Achanta, Prasanta; Johnson, Brian; Seo, Gab-Su; Maksimović, Dragan

A multilevel DC to three-phase AC architecture for photovoltaic power plants Journal Article

In: IEEE Transactions on Energy Conversion, vol. 34, no. 1, pp. 181–190, 2018.

Links | BibTeX | Tags: inverters

14.

Sinha, Mohit; Dörfler, Florian; Johnson, Brian; Dhople, Sairaj

Stabilizing phase-balanced or phase-synchronized trajectories of Van der Pol oscillators in uniform electrical networks Proceedings Article

In: Allerton Conference on Communication, Control, and Computing, pp. 335–340, IEEE 2018.

Links | BibTeX | Tags: inverters, modeling

13.

Khan, Mohammed; Lin, Yashen; Johnson, Brian; Purba, Victor; Sinha, Mohit; Dhople, Sairaj

A reduced-order aggregated model for parallel inverter systems with virtual oscillator control Proceedings Article

In: Workshop on Control and Modeling for Power Electronics, pp. 1–6, IEEE 2018.

Links | BibTeX | Tags: inverters, modeling

12.

Achanta, Prasanta; Sinha, Mohit; Johnson, Brian; Dhople, Sairaj; Maksimović, Dragan

Self-synchronizing series-connected inverters Proceedings Article

In: Workshop on Control and Modeling for Power Electronics, pp. 1–6, IEEE 2018.

Links | BibTeX | Tags: inverters, modeling

2017

11.

Johnson, Brian; Rodriguez, Miguel; Sinha, Mohit; Dhople, Sairaj

Comparison of virtual oscillator and droop control Proceedings Article

In: Workshop on Control and Modeling for Power Electronics, pp. 1–6, IEEE 2017.

Links | BibTeX | Tags: inverters, modeling

2015

10.

Sinha, Mohit; Dörfler, Florian; Johnson, Brian; Dhople, Sairaj

Uncovering droop control laws embedded within the nonlinear dynamics of van der pol oscillators Journal Article

In: IEEE Transactions on Control of Network Systems, vol. 4, no. 2, pp. 347–358, 2015.

Links | BibTeX | Tags: inverters, modeling

9.

Johnson, Brian; Sinha, Mohit; Ainsworth, Nathan; Dörfler, Florian; Dhople, Sairaj

Synthesizing virtual oscillators to control islanded inverters Journal Article

In: IEEE Transactions on Power Electronics, vol. 31, no. 8, pp. 6002–6015, 2015.

Links | BibTeX | Tags: inverters

8.

Sinha, Mohit; Dhople, Sairaj; Johnson, Brian; Ainsworth, Nathan; Dörfler, Florian

Nonlinear supersets to droop control Proceedings Article

In: Workshop on Control and Modeling for Power Electronics, pp. 1–6, IEEE 2015.

Links | BibTeX | Tags: inverters, modeling

7.

Sinha, Mohit; Dörfler, Florian; Johnson, Brian; Dhople, Sairaj

Virtual oscillator control subsumes droop control Proceedings Article

In: American Control Conference, pp. 2353–2358, IEEE 2015.

Links | BibTeX | Tags: inverters, modeling

2014

6.

Salapaka, Srinivasa; Johnson, Brian; Lundstrom, Blake; Kim, Sangsun; Collyer, Scott; Salapaka, Murti

Viability and analysis of implementing only voltage-power droop for parallel inverter systems Proceedings Article

In: Conference on Decision and Control, pp. 3246–3251, IEEE 2014.

Links | BibTeX | Tags: inverters, modeling

5.

Dörfler, Florian; Dhople, Sairaj; Johnson, Brian; Hamadeh, Abdullah

Synchronization of nonlinear circuits in dynamic electrical networks Proceedings Article

In: European Control Conference, pp. 552–557, IEEE 2014.

Links | BibTeX | Tags: inverters, modeling

2013

4.

Johnson, Brian; Dhople, Sairaj; Hamadeh, Abdullah; Krein, Philip

Synchronization of parallel single-phase inverters with virtual oscillator control Journal Article

In: IEEE Transactions on Power Electronics, vol. 29, no. 11, pp. 6124–6138, 2013.

Links | BibTeX | Tags: inverters, systems

3.

Johnson, Brian; Dhople, Sairaj; Cale, James; Hamadeh, Abdullah; Krein, Philip

Oscillator-based inverter control for islanded three-phase microgrids Journal Article

In: IEEE Journal of Photovoltaics, vol. 4, no. 1, pp. 387–395, 2013.

Links | BibTeX | Tags: inverters

2.

Dhople, Sairaj; Johnson, Brian; Hamadeh, Abdullah

Virtual oscillator control for voltage source inverters Proceedings Article

In: Allerton Conference on Communication, Control, and Computing, pp. 1359-1363, 2013.

Links | BibTeX | Tags: inverters, modeling

2011

1.

Johnson, Brian; Krein, Philip; Chapman, Patrick

Photovoltaic AC module composed of a very large number of interleaved inverters Proceedings Article

In: Applied Power Electronics Conference, pp. 976-981, 2011.

Links | BibTeX | Tags: inverters, systems