Enhancing Power System Stability with GFM-BESS: A Case Study on A Real Incident in Denmark

ENHANCING POWER SYSTEM STABILITY WITH GFM-BESS: A CASE STUDY ON A REAL INCIDENT IN DENMARK Paper ID: WISO25-26 Hong Gong, Liang Lu, Yicheng Liao, Jun Bum Kwon, Nan Qin, Ana B Montesinos, Ander G Lameiras Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau OUTLINE ▪Background & Motivation ▪Methodology (Simulation setup and approach) ▪Base Case Results ▪GFM-BESS Cases Results ▪Conclusion Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau BACKGROUND •EU 2024: 47% of electricity from renewable sources. •Denmark: 88% renewable electricity → highest share in the EU. •2030 Target: >30 GW renewable integration (onshore/offshore wind, solar). •System Shift: Toward decarbonized, decentralized, and inverter-dominated operation. Solar Onshore wind Offshore wind System characteristic •Decarbonized •Decentralized •PEID-dominant Renewable energy integration towards 2030 EU renewable energy share 2024 Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau CHALLENGES •Growing inverter-based generation (mainly GFL) → weaker system strength. •Slow or delayed controller response → reduced support during disturbances. •Combined effect → higher risk of voltage fluctuations, low-frequency oscillations, RoCoF, and transient instability. Frequency measurement at EDR 400kV station ROCOF > 2.5 Hz/sec. [Ref] Oscillation on 29 December 2024, captured by Energinet electricity control center. Oscillation magnitude (MW) Generation mix (MW) Shutdown of the last central power plant Down regulation of the wind farms Startup of central power plants Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau MOTIVATION •Need for new stability solutions: Traditional gridfollowing inverters rely on existing voltage and frequency references, limiting their ability to support system stability. •Emerging solution: GFM-BESS can independently establish voltage/frequency, deliver rapid active/reactive power, and provide synthetic inertia. •Danish initiative: Energinet’s GFM Deployment Project collaborates with OEMs/developers to test GFM devices using detailed EMT models → accelerates adoption and standardization. •Real-Event Validation Opportunity: Test GFMBESS in actual system disturbances to evaluate performance. Available to download: https://en.energinet.dk/about-our-reports/reports/towards-a-stable-andsustainable-future-with-grid-forming-technologies/ Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau INCIDENT OVERVIEWDK2, AUGUST 6, 2020 •Sequential faults: Two 400 kV line trips further reduced voltage support and system strength. •Cascade effects: SynCon at BJS and SB-HVDC tripped, isolating a 400 kV island with minimal local generation. •Takeaway: The event exposed how a sudden change of grid strength affects system stability and highlighted the need for near-instant active/reactive power support. •Use in study: Provides a realistic EMT test case to compare the existing system with a hypothetical GFM-BESS solution. ASV HKS BJS ISH HVE SB-HVDC KO-HVDC sc HKS_G sc BJS_G 400 kV HVDC sc SynCon DK1 German GØR Sweden Decoupled in 400 kV lines 220kV 132 kV GLN 1st fault 2nd fault Overview of DK2 incident on 6th August 2020, (a) Geographical description of DK2 incident, (b) Active power at Storebælt LCC HVDC, where “Meas” = Measurement, “EMT” = simulation results from Electro-magnetic simulation tool and “PDT” = simulation results from RMS based simulation tool. KO_P(Meas.) KO_P(EMT) KO_P(PDT) SB_P(Meas.) SB_P(EMT) SB_P(PDT) Active power in KO-HVDC Active power in SB-HVDC Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau METHODOLOGY ASV HKS BJS ISH HVE SB-HVDC KO-HVDC sc HKS_G sc BJS_G 400 kV HVDC sc SynCon 220kV 132 kV ASV HKS BJS ISH HVE SB-HVDC KO-HVDC sc HKS_G 400 kV HVDC sc SynCon 220kV 132 kV GFM-BESS ASV HKS BJS ISH HVE SB-HVDC KO-HVDC sc BJS_G 400 kV HVDC sc SynCon 220kV 132 kV GFM-BESS Simulation Environment •EMT simulation platform developed by Energinet [1] with vendor-specific DK2 models. •Replicates 6 Aug 2020 incident: lines, transformers, loads and switching. •GFM-BESS model scaled to match SynCon capacity. System Configurations •Base Case: Two SynCons (HKS & BJS). •Test Case: One SynCon replaced with GFM-BESS. Parameter Variations •Location: BJS vs. HKS. •Capacity: 150 / 200 / 250 MW. •Control tuning: inertia constant & voltage parameters. (a) Base Case with two SynCons (b) Test Case with GFM-BESS at BJS (c) Test Case with GFM-BESS at HKS [1] Liao, Y., Lu, L., Kwon, J. B., Qin, N., Muthumuni, D., Pipelzadeh, Y., and Dirks, K.: ‘Enabling systemlevel EMT studies of Danish power systems’, Proc. CIGRE Paris Session, Paris, France, 2024,pp. 1–10 Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau SIMULATION RESULTS Base Case-SynCon Configuration (a) Voltage at BJS and HKS (b) Active power of HVDCs (c) Reactive power of SynCons at BJS and HKS •t ≈ 12 s: single-phase fault on BJS_400_ISH line → cleared by disconnecting the faulted phase. •t ≈ 13 s: fault reapplied → line trips, simulating first auto-reclosure attempt failure. •t ≈ 15–16.5 s: second fault → BJS_400_HVE line trips → large voltage drop in affected area. Voltage at HKS Voltage at BJS Active power of KO Active power of SB Reactive power of SynCon at BJS Reactive power of SynCon at HKS ▪Sequential disturbances at BJS lines reduce system strength and voltage support. ▪SynCons at BJS & HKS inject reactive power and fault current, but: •Response too slow to restore voltages promptly. •HVDC commutation failures occur due to voltage dips. •Active power oscillations observed at both HVDC links. Klik for at redigere teksttypografierne i masteren •Andet niveau •Tredje niveau •Fjerde niveau •Femte niveau SIMULATION RESULTS Test Case1-GFM-BESS replacement (250MW at BJS) (a) Voltage at BJS and HKS (b) Active power of HVDCs (c) Reactive power of SynCons/GFMBESS at BJS and HKS •Replacing BJS SynCon → near-instantaneous reactive support. •Stabilizes AC voltages at BJS & HKS → prevents HVDC commutation failures. •Mitigates active power oscillations at SB-HVDC and KO-HVDC. •SynCon at HKS remains operational; system voltage & frequency stable. GFM-BESS provides fast voltage support, eliminating commutation failures seen in the Base Case. Key Takeaway: Voltage at HKS Voltage at BJS Active power of KO Active power of SB Reactive power of GFM-BESS at BJS Reactive power of SynCon at HKS