Smart Grid Solutions

Grid-Forming Inverters: A Comparative Study of Different Control Strategies ----------------------------------------------------------------------------------- As grid-forming inverters (GFMIs) are anticipated to play a leading role in future power systems, comprehensive understanding of their dynamics and control strategies becomes essential. Our recent article delves deep into this, offering a comparative study including: 1)      Detailing the control structures and tuning of four different control strategies for GFMIs (Droop, VSG, Compensated Generalized VSG, and Adaptive VSG). 2)      Conducting extensive frequency domain analysis employing impedance-based stability analysis, exploring various scenarios (SCR variations, Xg/Rg variations, operating point variations, dynamics of virtual impedance, and dynamics of inner current and voltage loops). 3)      Validating the frequency domain analysis through EMT simulations. 4)      Testing against external grid disturbances (frequency deviations, phase shifts, and voltage sags) in both strong and weak grid connections.   For more information: Article Title: Grid-Forming Inverters: A Comparative Study of Different Control Strategies in Frequency and Time Domains. Authors: Nabil Mohammed, Harith Udawatte, Weihua Zhou, Professor David Hill, Behrooz Bahrani. Journal: IEEE Open Journal of the Industrial Electronics Society. Links [Open Access]: https://lnkd.in/gE_fgJ6F ; https://lnkd.in/gMz-S4KE .   Special thanks to the Australian Renewable Energy Agency (ARENA) and the Australian Research Council for funding this work.   #powerelectronics #forminginverters #renewableenergy #gridintegration #sustainability #energytransition

If you are an early-stage researcher who wants to dive into the grid-forming (#GFM) inverter world, we have created a step-by-step tutorial based on #UNIFI’s GFM reference design— as part of UNIFI’s educational initiative. ⚙️Written in easy-to-follow language, this tutorial walks you through: ✅ The control architecture of GFM inverters ✅ How to pick control gains for outer voltage and inner current loops ✅ LCL filter design basics ✅ How current limiters work and why they matter ⚙️This tutorial also comes with hands-on guidance for navigating UNIFI’s open-source GitHub repository, which contains everything you need to build your first GFM inverter: ✅ Simulation models (both average and EMT models) ✅ PCB design files ✅ Embedded control code for running hardware ✅ Detailed documentation for single-phase and three-phase GFM hardware—covering all the bits and pieces: component selection, thermal considerations, sensing-circuit design, and more! Starting from scratch, building a working GFM inverter setup can take years. With this tutorial and the resources in UNIFI’s repository, you can skip most of the setup headaches—saving 1–2 years of work! 🔗If you’re ready to get started, check out the tutorial and explore the repository—links in the first comment. Rahul Mallik Weiqian Cai Kamakshi Tatkare Jakob Triemstra Cuauhtemoc Macias

Grid-forming control to achieve a 100% power electronics interfaced power transmission systems by Taoufik Qoria -”Nouvelles lois de contrˆole pour former des r´eseaux de transport avec 100% d’´electronique de puissance” ´ECOLE DOCTORALE SCIENCES ET M´ETIERS DE L’ING´ENIEUR L2EP - Campus de Lille  Abstract: The rapid development of intermittent renewable generation and HVDC links yields an important increase of the penetration rate of power electronic converters in the transmission systems. Today, power converters have the main function of injecting power into the main grid, while relying on synchronous machines that guaranty all system needs. This operation mode of power converters is called "Grid-following". Grid-following converters have several limitations: their inability to operate in a standalone mode, their stability issues under weak-grids and faulty conditions and their negative side effect on the system inertia.To meet these challenges, the grid-forming control is a good solution to respond to the system needs and allow a stable and safe operation of power system with high penetration rate of power electronic converters, up to a 100%. Firstly, three grid-forming control strategies are proposed to guarantee four main features: voltage control, power control, inertia emulation and frequency support. The system dynamics and robustness based on each control have been analyzed and discussed. Then, depending on the converter topology, the connection with the AC grid may require additional filters and control loops. In this thesis, two converter topologies have been considered (2-Level VSC and VSC-MMC) and the implementation associated with each one has been discussed. Finally, the questions of the grid-forming converters protection against overcurrent and their post-fault synchronization have been investigated, and then a hybrid current limitation and resynchronization algorithms have been proposed to enhance the transient stability of the system. At the end, an experimental test bench has been developed to confirm the theoretical approach.  VIEW FULL THESIS: https://lnkd.in/dcTJU-9v

Grid-Forming PV Integration for Enhanced Grid Stability ------------------------------------------------------------- As renewable penetration increases, maintaining grid stability without relying on synchronous generators has become a critical challenge. To address this, I designed and validated a grid-forming inverter system directly integrated with a photovoltaic (PV) source, controlled using droop control, and implemented in MATLAB Simulink. Unlike conventional grid-following PV systems, this architecture allows the PV inverter to form and regulate the grid actively, enabling stable operation even in weak or low-inertia grids. System Architecture & Key Design Parameters - Photovoltaic Source (DC Side) - PV Maximum Power (Pmp): 10.675 kW - PV Voltage at MPP (Vmp): 290 V - PV Current at MPP (Imp): 36.75 A The PV array is interfaced with a DC-link and grid-forming inverter, enabling seamless power conversion while maintaining dynamic control over voltage and frequency. - Grid-Forming Inverter (AC Side) - Injected Active Power: ≈ 10 kW - Grid Voltage: 400 V RMS - Nominal Grid Frequency: 50 Hz This setup reflects a realistic grid-connected PV scenario, where the inverter must operate under off-nominal frequency and voltage conditions while ensuring grid support. Why Grid-Forming Droop Control? By embedding droop control into the PV inverter, the system mimics the behavior of conventional synchronous generators, allowing the PV system to become an active grid asset rather than a passive energy source. ✔ Frequency Support: Active power modulation in response to frequency deviations ✔ Voltage Regulation: Reactive power sharing for voltage stability ✔ Black-Start Capability: Grid formation without an external voltage reference ✔ Scalability: Stable parallel operation of multiple PV inverters without communication - Effective Voltage Control: Reactive power droop ensured stable voltage profiles, even during transient conditions. - High Grid Resilience: The system maintained synchronism and stability during disturbances, demonstrating strong suitability for weak and low-inertia grids. Key Insights & Impact The simulation confirms that PV-based grid-forming inverters can: - Replace traditional synchronous generation roles - Enable higher renewable penetration without compromising stability - Support future power systems dominated by inverter-based resources This work demonstrates how PV systems can evolve from grid-following to grid-forming, transforming renewables into stability-providing elements of modern power systems. Feel free to reach out if you’d like to collaborate on similar projects.  #MATLAB #SIMULINK #GridForming #PVIntegration #DroopControl #PowerElectronics #RenewableEnergy #InverterBasedResources #SmartGrids

Grid strength is frequency-dependent, so how do we actually stabilize it? ⚡ In the previous post, I highlighted that stability in inverter-based systems is governed by the interaction: Z_grid(s) and Z_inv(s) and the critical condition: Z_grid(s) / Z_inv(s) = -1 When this condition is approached at any frequency, the system loses stability. So how does grid-forming (GFM) control change this? A GFM inverter does not behave as a current source following the grid. It behaves as a controlled voltage source, which fundamentally changes the interaction. Impedance perspective The inverter is no longer passively reacting to the grid. It actively reshapes its output impedance: Z_inv_new(s) = Z_inv(s) + Z_virtual(s) where: Z_virtual(s) = R_v + jX_v What this actually does It modifies both magnitude and phase of Z_inv(s): - Adds resistive damping (R_v) → reduces oscillations - Adjusts reactance (X_v) → shifts resonance frequencies - Increases phase margin → avoids −180° crossing Control dynamics matter GFM control (droop, vsm, or matching control) introduces: - Fast voltage regulation - Power–frequency coupling - Intrinsic damping without PLL This removes the unstable feedback loop: current → voltage → PLL → current Result in the frequency domain The impedance ratio: Z_grid(s) / Z_inv(s) is reshaped so that it does NOT approach the critical point (-1, 0) across the relevant frequency range. Why GFL struggles here Grid-following (GFL) inverters: - depend on PLL - introduce phase lag - behave as current sources They cannot actively control Z_inv(s), and in weak grids this often leads to: - low-frequency oscillations (≈ 5–20 Hz) - poor damping - instability under disturbances Real system implication In weak grids (low SCR), stability is not improved by “adding more power” It is improved by reshaping the impedance interaction Key takeaway Grid-forming control does not “increase strength” in the traditional sense. It redefines the system dynamics by actively shaping Z_inv(s) so the instability condition: Z_grid(s) / Z_inv(s) = -1 is never reached. #GridForming #Inverters #PVInverter #PowerElectronics #PowerSystems #GridStability #RenewableEnergy #SolarEnergy #FutureGrid #Hitachi #SolarPower #EnergyStorage #BESS #BatteryStorage #SmartGrid #Microgrids #VirtualInertia #SCR #SMASolar #ABB #UtilityScaleSolar #EnergyTransition #CleanEnergy #EnergyEngineering #Vision2030 #ElectricalEngineering #ClimateTech #NEOM #KSAEnergy #SynchronousCondenser

I’m pleased to share that my latest research paper has been published in the IEEE Xplore Digital Library. Paper link: https://lnkd.in/d8nHQktB As power systems continue to evolve toward renewable-dominated architectures, maintaining stability under dynamic operating conditions becomes increasingly challenging especially in Solar–HVDC configurations. In this work, I explore the role of grid-forming Battery Energy Storage Systems (BESS) in addressing one of the critical issues: PV curtailment events and their impact on DC-link stability. The paper proposes an enhanced grid-forming control strategy that enables BESS to operate with voltage-source behavior, ensuring fast and reliable system response during abrupt solar power reductions. A detailed dynamic model was developed and validated in MATLAB/Simulink. Key findings: - BESS compensates a 40% PV curtailment within 100 ms - DC voltage deviations are limited to within ±2% - Achieves ~60% reduction in voltage transients compared to grid-following control These results highlight the importance of grid-forming BESS not just as a storage element, but as an active stabilizing component in future HVDC-based renewable grids. Looking forward to engaging discussions with colleagues working on grid-forming technologies, HVDC systems, and energy storage integration. #IEEE #HVDC #BESS #GridForming #PowerSystems #EnergyTransition #Renewables

Central Electricity Authority (Cea) 2026 Amendment Sets New Technical Standards for #BESS, #Solar, and #Wind Projects in India effective from 1st April 2027. For years, BESS were largely seen as energy buffers. This amendment changes that narrative completely. Now, every BESS is expected to behave like a grid participant, not just a storage unit. • Active & reactive power control • Voltage regulation at the point of interconnection • Frequency response support This effectively aligns BESS with the expectations of modern #gridcodes. From a system design perspective, this pushes developers toward: • Advanced EMS architectures • High-performance PCS selection (with dynamic Q control) • Robust testing & validation frameworks ➤ Black Start & Grid-Forming Mandate For projects ≥50 MW, the regulation introduces a powerful requirement: Black start capability + Grid-forming inverter technology This is not a small upgrade—it’s a paradigm shift. Grid-forming (GFM) systems: • Establish voltage & frequency from scratch • Enable system restoration after total blackout • Support weak grid conditions where traditional generation struggles This aligns closely with global trends where grids are moving from synchronous inertia → #inverter-based stability. ➤ Performance Accountability Over 15 Years • ≥90% output after 5 years • ≥80% after 10 years • ≥70% after 15 years This introduces real accountability across the value chain: • Cell selection strategy • Thermal management design • Degradation modelling • Warranty structuring ➤ Solar: Moving Toward Traceability & Durability • Mandatory bypass diodes (reducing hotspot risks) • RFID tagging for lifecycle traceability • 25-year operational design requirement For floating solar: • UV & salt-resistant materials • Wind tunnel validation • Buoyancy testing This signals a move toward bankability through engineering discipline, not just capacity bidding. ➤ Wind Energy ≥500m distance from residential zones (noise mitigation) Offshore-specific requirements: • Scour protection • Marine-grade foundations • J-tube / I-tube cable systems • Offshore substations with helipad access This ensures that India’s offshore ambitions are built on global engineering standards from day one. ➤ Digital Data, Control & Grid Visibility • Remote operability via load dispatch centers • 90-day high-resolution data storage • Fault recording and analytics readiness ➤ Safety & Compliance • Multi-layer protection systems • Fire safety integration • Compliance with National Building Code From where I see it, this amendment does three things: → Only serious, system-level players will survive → Pushes India toward grid-forming future → Shifts focus from CAPEX to lifecycle performance Now is the time to rethink—compliance isn’t just about standards; it’s about building systems that perform for 15+ years. #cea #bess #energystorage #renewables #gridstability #indiaenergy #solarpanel #powersector #blackstart #lfpbattery

⚖️🔧⚡ Transitioning from Grid-Following (GFL) to Grid-Forming (GFM) in Solar + BESS Projects As more renewable projects move toward grid-forming capabilities, it’s critical to understand that success depends on two distinct but equally important layers: 👉 Power Electronics (device level) 👉 GPM – Grid Performance Management (plant/system level) They solve different parts of the problem — and both must evolve together. 🔌 1. Power Electronics – The Foundation Before (GFL): -Inverters follow grid voltage & frequency (PLL-based) -Require a strong grid -Limited stability support (no inertia, -weak voltage control) After (GFM): -Inverters create voltage & frequency -Act like synchronous machines (virtual inertia, droop control) -Operate in weak grids or islanded mode 🔧 Key Changes: Control shift: PLL → Droop / Virtual Synchronous Machine (VSM) Add: Frequency droop (P–f) Voltage droop (Q–V) Synthetic inertia OEM firmware & protection updates (e.g., Sungrow, Tesla, SMA) Integration of BESS for fast dynamic support Enhanced fault response & ride-through capability 🧠 2. GPM – The System-Level Brain GPM coordinates the entire plant: Inverters BESS Plant Power Controller (PPC) Interfaces with utilities (e.g., Oncor) and ISOs (e.g., ERCOT) 🔧 What Changes with GFM: ✔ PPC Upgrades Grid-forming dispatch Multi-unit coordination Voltage & frequency reference control Black start capability ✔ EMS Enhancements BESS dispatch optimization SOC management (maintain headroom for grid support) ✔ Grid Compliance Meet requirements like NOGRR272 Fast frequency response Voltage ride-through Disturbance support ✔ Protection Updates Adaptive protection schemes Revised relay coordination Anti-islanding updates ✔ Operational Modes Grid-connected ↔ Grid-forming Grid-forming ↔ Islanded Black start sequences ⚖️ Power Electronics vs GPM – Key Difference Power Electronics: Creates voltage & frequency (device-level stability) GPM: Coordinates and sustains plant-wide performance ⚡ Real Example: 40 MW Solar + 10 MW / 20 MWh BESS Without GFM: PV becomes unstable in weak grids No meaningful frequency support With GFM: BESS + inverter form the grid Stabilize voltage & frequency GPM ensures: SOC ~50–70% (bidirectional support) Dynamic dispatch Alignment with ERCOT signals 🚧 Key Risks if Not Done Right Control instability (oscillations) BESS depletion → loss of support Protection miscoordination Non-compliance (e.g., NOGRR272) Interconnection delays ✅ Bottom Line ⚡ Power Electronics = “Can we form the grid?” 🧠 GPM = “Can we control it reliably at scale?” 👉 You need both: Power electronics enables the capability GPM ensures it works in real-world grid conditions #SolarEnergy #RenewableEnergy #EnergyStorage #BESS #GridForming #GridFollowing #PowerElectronics #EnergyTransition #ERCOT #GridStability #CleanEnergy #Inverters #Engineering #PowerSystems #EnergyManagement #UtilityScale #SolarProjects #Transmission #Infrastructure

Not all #grid_forming (GFM) controls are created equal. Three generic GFM approaches are commonly referenced today: • REGFM_A1 → Droop-based control • REGFM_B1 → Virtual Synchronous Machine (VSM) • REGFM_C1 → Hybrid GFM control The real shift could be happening with REGFM_C1. Why? Because hybrid GFM architectures go beyond droop or inertia emulation, and start addressing one of the toughest challenges in modern grids: ⚡ Pulsating AI/data center loads (0.1–30 Hz) By adding high-bandwidth feedforward compensation on the current/power control path. This is where things change. Grid-forming is no longer just about “inertia replacement.” It’s evolving into a power quality and stability engine for the next generation of loads. #Grid_Forming #Grid_Following #BESS #Data_Centers #AI_Loads

⚡ Grid-Forming Batteries = The Inverter That Sets the Rules 🔋 Traditional grid inverters follow the grid's signal. Grid-forming batteries create it. That distinction is becoming one of the most important in energy storage. 🔌 Grid-Following = Inverters wait for instructions, matching existing voltage and frequency. This works when spinning turbines are holding the grid stable. But as renewables replace those turbines: • Less synchronous generation • Less inertia • Frequency deviations happen faster than grid-following assets can react → The reference signal weakens. The grid becomes more fragile. Spain's April 2025 blackout was a live demonstration… Voltage control failed, partly because regulations prevented inverters from providing it. ⚙️ Grid-Forming = Inverters generate the reference themselves The inverter sets its own voltage and frequency, even in weak or unstable conditions. This enables: • Synthetic inertia → millisecond response, no rotating parts • Black start → restart a grid from zero • System strength → support weak transmission areas • Islanded operation → run without a grid connection 🌍 Deployment is already happening: • Europe: ENTSO-E is moving to mandate grid-forming for all new storage >1 MW • UK: £323M Stability Pathfinder programme piloting grid-forming stability services • Australia: Leading at scale with 5 grid-forming BESS projects, including the 1 GWh Western Downs Battery 📈 With Wood Mackenzie estimating ~1,500 GW of new BESS by 2034, the future needs these batteries to lead, not just follow. #EnergyStorage #BESS #GridForming #GridStability #Renewables #EnergyTransition